The researchers multiplied isolate Aglr64 of N. tropicalis on leaves of the American grape cultivar Vitis labrusca cv. Niagara Rosada, collected urediniospores and incubated them on polystyrene plates. After 16 hours at 22 degrees Celsius, 88% of the spores had developed long germ tubes.

Germinated spores were collected for RNA sequencing because this approach allowed pathogen RNA to be isolated without the large amount of plant material that would otherwise contaminate the sample. Paired-end sequencing generated more than 90 million trimmed reads. Assembly with Trinity produced 64,333 transcripts, including 28,968 longer than 1,000 base pairs, while BUSCO analysis indicated that 89.6% of the assembly contained sequences corresponding to conserved fungal single-copy genes.

The transcriptome also yielded full-length coding sequences for two beta-tubulin genes and a glyceraldehyde-3-phosphate dehydrogenase gene. One beta-tubulin sequence, NtBetaTub1, shared 100% identity with a previously reported N. tropicalis gene, whereas NtBetaTub2 was described as a possible second isoform not previously reported in the species. Two glyceraldehyde-3-phosphate dehydrogenase contigs differed by a single nonsynonymous substitution and were interpreted as allelic variants of a single-copy gene.

The researchers used these sequences, together with a cytochrome c oxidase subunit III reference, to normalize expression measurements. The complete beta-tubulin sequences may also support monitoring of mutations associated with benzimidazole fungicide resistance, although the present study did not test resistance. Of the 64,333 assembled transcripts, 6,081, or 9.45%, encoded predicted secreted proteins without a transmembrane domain.

Applying EffectorP with a probability threshold greater than 0.8 reduced this collection to 303 candidate effectors. After predicted signal peptides were removed, the mature protein sequences were clustered at a 40% global amino-acid identity threshold. The candidates formed 142 putative families: 65 contained a single member, while the other 77 contained between two and seven.

This distribution shows that the predicted repertoire was dominated by distinct and relatively small sequence groups rather than a few large expanded families. Seven of the 15 most highly expressed candidates had no detectable homologs in the National Center for Biotechnology Information non-redundant protein database. Those 15 candidates, designated NtEC-01 through NtEC-15, represented 13 sequence families and provided a broad sample of the predicted repertoire.

Four were homologous only to proteins from rust fungi, three had similarities restricted to Basidiomycota, and NtEC-10 showed sequence similarity across Basidiomycota and Ascomycota. Reverse-transcription PCR produced the expected mature coding-region amplicons for 14 candidates. NtEC-06 instead produced a product of approximately 380 base pairs rather than the predicted 480 base pairs, corresponding to an overall validation rate of 93.33% for the computational predictions.

These results establish the presence and relative abundance of candidate transcripts during spore germination; they do not by themselves demonstrate secretion, delivery or activity of each protein during infection. Reverse-transcription quantitative PCR separated the candidates into six expression patterns. NtEC-08 accumulated transcripts in both dormant and germinated spores, whereas NtEC-07 peaked in germinated spores and at 24 hours post-inoculation.

NtEC-02, NtEC-03, NtEC-10, NtEC-04, NtEC-11 and NtEC-13 reached their highest transcript levels in germinated spores. NtEC-01 and NtEC-14 peaked at 24 hours post-inoculation; NtEC-05 and NtEC-12 peaked at both 24 and 48 hours; and NtEC-09 and NtEC-15 peaked at 48 hours. Seven candidates were therefore associated chiefly with penetration and early biotrophic colonization.

Chitin-targeted fluorescence microscopy provided a developmental framework for interpreting those measurements. At 24 hours post-inoculation, N. tropicalis had formed elongated germ tubes ending in differentiated appressoria, with hyphae entering host tissue through stomatal openings. Similar structures remained visible at 48 hours, when intracellular infection hyphae indicated a transition from penetration to early colonization.

At 72 hours, infection hyphae were proliferating within the leaf, and by five days they had formed broad, coalescing intercellular networks. Closed and partly open uredia containing urediniospores appeared at seven days, while mature open pustules were present at nine days. Under these experimental conditions, penetration occurred at 24–48 hours, colonization was observed from 72 hours to five days, and reproduction began at seven to nine days.

Functional testing used the type III secretion system of Pseudomonas fluorescens EtHAn to deliver nine selected NtEC proteins, without their native signal peptides, into N. benthamiana leaves. Each candidate was co-infiltrated with AvrB, a bacterial protein that triggers a hypersensitive response. Suppression was scored when a candidate reduced or prevented tissue collapse in at least 40% of co-infiltrated leaves.

Across three independent experiments with ten biological replicates each, NtEC-05, NtEC-09 and NtEC-10 produced suppression frequencies of 53% to 66%, categorized as moderately high activity. NtEC-11, NtEC-12 and NtEC-13 produced frequencies of 40% to 46%, categorized as moderate activity. NtEC-03, NtEC-14 and NtEC-15 remained below 30% and were considered inactive in this assay.

AlphaFold 3 models offered preliminary structural information about the six candidates that reduced cell death. Predictions for NtEC-10 and NtEC-12 had high confidence, with predicted TM-scores above 0.5, while models for NtEC-05, NtEC-09, NtEC-11 and NtEC-13 had scores below 0.5 and were classified as low confidence. NtEC-10 showed sequence and structural similarity to a predicted glycan-binding protein from Phakopsora pachyrhizi.

That comparison may guide later biochemical work, but it does not establish glycan binding or any other biochemical activity. The study also did not determine whether the NtEC proteins act on RIN4, another immune regulator or through another route. Their measured ability to suppress an AvrB-triggered response only shows activity in the tested heterologous delivery assay.

Several scope limitations constrain interpretation of the results. The research used one N. tropicalis isolate and one susceptible grape cultivar, while the functional assays took place in N. benthamiana rather than grapevine. The experiment did not show that any candidate is required for virulence, that the proteins are secreted during natural infection or that they directly suppress immunity in grapevine.

Most expression peaks occurred during germination or early infection, and none of the selected candidates showed preferential expression at the later reproductive stages. Even so, the study assembled the first broad transcriptomic inventory of predicted N. tropicalis effectors, mapped candidate expression against an observed infection timeline and experimentally identified six proteins with cell-death-suppressing activity. These resources provide defined targets for subsequent work on secretion, host interactions and resistance-relevant effector recognition, without yet establishing a clinical, agricultural or disease-control outcome.

Subject of Research: Candidate effector proteins and stage-specific expression in the grapevine rust fungus Neophysopella tropicalis

Article Title: Grapevine rust fungus Neophysopella tropicalis deploys protein effectors with plant immunity-suppressing activity during sequential stages of pathogenesis

Article References: Maia, T., Ferro, J. V., Husein, G., Bombardelli, R. G. H., & Monteiro-Vitorello, C. B. (2026). Grapevine rust fungus Neophysopella tropicalis deploys protein effectors with plant immunity-suppressing activity during sequential stages of pathogenesis. Plant Cell Reports, 45(11), Article 337. https://doi.org/10.1007/s00299-026-03980-w

Image Credits: AI Generated

DOI: 10.1007/s00299-026-03980-w

Keywords: Neophysopella tropicalis, grapevine leaf rust, fungal effectors, plant immunity, urediniospores, transcriptomics, host penetration, hypersensitive response, AlphaFold 3, biotrophic fungi, Grapevine, rust

The scale of the improvements is what makes the findings remarkable. Compared with conventional fertilization, the fully enriched biochar treatment raised soil organic carbon by 109 percent and cation exchange capacity by 68 percent, while cutting soil bulk density by 19 percent. Those three numbers describe a soil that stores more carbon, holds and exchanges more nutrients, and is physically less compacted — a combination that directly benefits roots, which must push through dense soil to reach water and nutrients. In semi-arid regions where drought degrades soil structure year after year, reversing all three trends at once with a single amendment is an unusual outcome.

Below ground, the effects were even more dramatic. Root surface area increased 2.8-fold under the enriched treatment, and fine roots — those thinner than half a millimeter — made up 71 percent of total root length. This shift in root architecture matters enormously for drought adaptation. Fine roots are the workhorses of water and nutrient uptake, exploring soil pores that thicker roots cannot penetrate. A root system dominated by fine roots can exploit a much larger volume of soil for the same carbon investment, effectively giving the vine a larger and more efficient foraging network precisely when water is scarce. The researchers attribute this architectural shift partly to the biostimulant components, particularly brassinosteroid, a plant hormone known to regulate root development, and partly to the improved physical conditions created by the biochar itself.

The physiological evidence of drought relief was equally clear. Leaf relative water content — a direct measure of how well-hydrated the foliage is — climbed from 68.5 percent to 88.2 percent under the fully enriched treatment. Meanwhile, two classic biochemical stress markers moved sharply in the right direction: proline, an amino acid that accumulates when plants are water-stressed, fell by 67 percent, and malondialdehyde, a byproduct of oxidative damage to cell membranes, dropped by 62 percent. In plain terms, the vines were no longer desperately conserving water or repairing membrane damage. They were functioning as well-hydrated, low-stress plants despite receiving no irrigation at all.

These physiological gains translated into photosynthetic performance and nutrient uptake. The enriched treatment improved photosynthetic efficiency and increased the uptake of essential nutrients, consistent with the combined action of the amendment’s components. The arbuscular mycorrhizal fungus Rhizophagus irregularis extends the root’s effective reach through fungal hyphae that access phosphorus and other nutrients beyond the depletion zone around roots. The bacteria Azospirillum brasilense and Pseudomonas fluorescens contribute nitrogen fixation, hormone production, and general growth promotion. Biochar serves as an ideal carrier for these organisms, offering a porous, carbon-rich habitat that protects microbial inoculants from the harsh conditions of semi-arid soil — a role that has attracted growing attention in recent years as researchers seek reliable ways to keep beneficial microbes alive long enough to colonize plant roots.

The enrichment strategy is what distinguishes this work from most biochar studies. Plain biochar has been tested extensively in vineyards, with mixed results that often depend on soil type, pyrolysis conditions, and climate. Here, the researchers layered multiple functions onto the same carbon matrix. Chitosan, a biopolymer derived from crustacean shells, acts as a soil conditioner and elicitor of plant defense responses, and it can improve water retention in amended soils. Fulvic acid, a small-molecule component of humic substances, chelates nutrients and enhances their mobility toward roots. Brassinosteroid tunes hormonal signaling for stress tolerance and root growth. By loading all of these onto grapevine-pruning biochar — itself a clever piece of circular agriculture, since the feedstock comes from the same vineyards being treated — the team created what is essentially a slow-release, biologically active soil supplement.

The four-year duration of the experiment, running from 2022 to 2025, lends the results particular weight. Many biochar trials last a single season, which raises questions about whether initial flushes of improvement will persist once the amendment’s labile fractions are consumed. Multi-year data showing sustained gains in soil carbon, root architecture, water status, and yield suggest that the enriched biochar is not merely a short-lived fertilizer spike but a durable modification of the soil-plant system. The seven treatments evaluated across the trial also allowed the researchers to isolate the contribution of each enrichment component, and the fully enriched formulation consistently outperformed simpler combinations.

Yield is where the story becomes genuinely viral-worthy for the agricultural world: the fully enriched treatment produced a 114 percent increase in yield relative to conventional fertilization. Doubling the productivity of rain-fed vines, without irrigation, in a semi-arid climate, is the kind of result that could reshape how marginal vineyard regions approach water scarcity. And the economics held up. The benefit-to-cost ratio for the fully enriched treatment was 2.95 — the highest among all treatments — meaning that every unit of money spent on the amendment returned nearly three units of value. For growers operating on thin margins in drought-prone regions, that ratio may matter as much as the yield figure itself, because it demonstrates that the approach is not just scientifically interesting but commercially viable.

The broader context is a growing scientific consensus that single-tool solutions are insufficient for climate adaptation in agriculture. Reviews of biochar research have emphasized that its effects on soil and plants depend on mechanisms that vary widely — carbon sequestration, water retention, microbial habitat, nutrient exchange — and that combining biochar with complementary technologies often outperforms biochar alone. Similarly, meta-analyses of mycorrhizal fungi and plant growth-promoting bacteria show consistent benefits for drought tolerance and nutrient uptake, but field delivery of living inoculants remains a persistent challenge. The enriched-biochar approach addresses that challenge directly by using the biochar’s porous structure as a protective carrier, effectively solving two problems — soil conditioning and microbial survival — with one material.

For the wine and grape industries, which face intensifying drought pressure across the Mediterranean, the Middle East, and other warm-climate regions, the study points toward a practical pathway: recycle vineyard pruning waste into biochar, enrich it with chitosan, fulvic acid, brassinosteroid, and proven microbial strains, and return it to the soil. The result, according to the Iranian research team led by Mohammad Saeed Tadayon of the Agricultural Research, Education and Extension Organization, is a soil that holds more carbon and water, roots that forage more efficiently, leaves that stay hydrated under stress, and harvests that roughly double. As climate change tightens its grip on rain-fed agriculture worldwide, a treatment that turns vineyard waste into vineyard resilience — profitably — is exactly the kind of innovation the sector has been waiting for.

Subject of Research: Enriched biochar amendments for drought resilience and productivity in rain-fed grapevines

Article Title: Biochar enriched with chitosan and biostimulants improves root architecture, nutrient uptake, and drought adaptation of rain-fed grapevines

Article References: Tadayon, M. S., Mousavi, S. M., Hosseini, S. M., & Sadeghi, S. (2026). Biochar enriched with chitosan and biostimulants improves root architecture, nutrient uptake, and drought adaptation of rain-fed grapevines. Plant and Soil. https://doi.org/10.1007/s11104-026-09031-3

Image Credits: AI Generated

DOI: 10.1007/s11104-026-09031-3

Keywords: biochar, grapevine, drought resilience, chitosan, fulvic acid, brassinosteroid, mycorrhizal fungi, plant growth-promoting bacteria, root architecture, soil organic carbon, rain-fed viticulture, biostimulants

The research team, led by Anne Janoueix of the EGFV research unit at the University of Bordeaux, INRAE and Bordeaux Sciences Agro, worked in an organic vineyard in Lapouyade, France, established in 2008 with Merlot vines grafted onto 101-14 MGt rootstock. Over the years, growers had planted plum trees, quince trees and field maples directly within the vine rows at spacings of five to nine metres. This created a natural experiment: some vines had lived beside trees for ten years, others for only five, and a third group grew in rows far from any trees. Because all vines shared the same soil, climate and management history, differences between the groups could be attributed with reasonable confidence to the trees and the length of time they had been co-cultivating with the vines.

The researchers sampled both bulk soil, collected roughly fifty centimetres from tree trunks, and rhizosphere soil, the thin, biologically charged layer clinging to grapevine fine roots. They measured a suite of physicochemical properties, including soil organic carbon, total nitrogen, pH, and extractable phosphorus, potassium and magnesium. The headline result was unambiguous: bulk soils near the ten-year-old plum trees contained significantly more soil organic carbon, at 1.71 percent compared with 1.16 percent near control vines, and significantly more total nitrogen, at 1.40 parts per thousand versus 1.01. Soils near the five-year-old trees showed intermediate values that did not differ significantly from the controls, hinting that these belowground changes accumulate gradually over years of co-cultivation.

The enzymatic story proved even more striking. Soil microbes secrete extracellular enzymes to break down complex organic matter and release the carbon, nitrogen and phosphorus they need, so measuring these enzymes reveals what microbial communities are actively investing in. The team quantified seven enzymes using fluorogenic substrates in high-throughput microplate assays: four carbon-acquiring enzymes including beta-glucosidase and cellobiohydrolase, two nitrogen-acquiring enzymes, and acid phosphatase for phosphorus. In the grapevine rhizosphere, every one of these functional categories showed significantly higher activity near the ten-year-old plum trees than near the young trees or in control rows. The bulk soil, by contrast, showed only modest and mostly non-significant differences, underscoring that the rhizosphere, not the whole soil volume, is where tree-vine interactions play out most intensely.

To interpret these patterns, the researchers applied vector analysis of eco-enzymatic stoichiometry, a framework that converts the relative activities of carbon-, nitrogen- and phosphorus-acquiring enzymes into two metrics: vector length, which signals relative microbial investment in carbon acquisition, and vector angle, which indicates the balance between nitrogen and phosphorus acquisition. In bulk soil, vector angles rose significantly near trees of both age cohorts compared with controls, exceeding forty-five degrees and pointing toward proportionally greater microbial investment in phosphorus-scavenging enzymes. This shift occurred even though extractable soil phosphorus pools barely changed, suggesting that trees altered microbial nutrient demand in ways not captured by conventional soil chemistry. In the rhizosphere, vector length tended to increase near the younger trees, hinting at heightened carbon investment in that compartment.

Notably, the surge in rhizosphere enzyme activity near older trees was not accompanied by any change in extractable DNA concentration, a rough proxy for microbial biomass. This dissociation matters: it implies that the microbial communities near trees did not simply become larger, but functionally reorganised, reallocating their enzymatic effort in response to altered substrate availability and nutrient demand. Rhizosphere microbes are known to adjust their functional investment rapidly, and the tree-driven enrichment of soil organic matter, through litterfall, pruning residues, root turnover and rhizodeposition, appears to have created conditions favouring a more metabolically active, phosphorus-hungry community around the vine roots.

The consequences extended above ground. In May 2024, the team used a hand-held Dualex fluorescence sensor to measure the Nitrogen Balance Index, the ratio of leaf chlorophyll to flavonol content, which serves as a non-destructive indicator of a vine’s instantaneous nitrogen status. Vines growing near the ten-year-old plum trees showed significantly higher NBI values than both the five-year-old cohort and the controls. Although petiole nitrogen and must nitrogen did not differ significantly among treatments on their own, the NBI correlated strongly and positively with both petiole nitrogen concentration and ammoniacal nitrogen in the must, reinforcing the interpretation that vines near mature trees were better nourished. Enhanced rhizosphere enzyme activity, the authors suggest, may have accelerated organic matter mineralisation and increased nitrogen availability to the vines.

Crucially, none of these belowground changes came at the vines’ expense. Yield per vine, measured by weighing all bunches at harvest in September 2024, showed no significant differences among treatments. Carbon isotope composition of the must, an integrative indicator of seasonal water stress, ranged from minus 25.99 to minus 27.15 parts per thousand and did not differ among groups, indicating little to no water limitation and no evidence of trees outcompeting vines for soil moisture. The one caveat is that 2024 was an exceptionally wet growing season in Bordeaux, so competition for water could yet emerge under drier conditions. Berry must from vines near older trees did show higher gluconic and tartaric acid contents and thus higher total acidity, a compositional shift that winemakers may find worth monitoring.

The temporal dimension of the study carries perhaps its most important practical message. Significant gains in soil organic carbon under agroforestry are typically reported only after fifteen years or more of tree establishment, and earlier studies often found weak or undetectable effects in systems younger than five years. Here, clear differences between the five- and ten-year cohorts, spanning soil chemistry, enzyme activity, stoichiometric strategy and vine nitrogen status, demonstrate that the benefits of vitiforestry build progressively as tree-vine interactions mature. The five-year-old trees generally produced intermediate responses, suggesting a trajectory rather than a threshold, and the pattern held when all tree species were pooled, indicating it was driven by planting age rather than species identity.

Vitiforestry remains rare in modern temperate viticulture, largely because growers fear competition between trees and vines, both above and below ground. Historic European systems such as hautains and joualles once embedded vines among fruit trees, but mechanisation and intensification largely erased them. This study, conducted under real commercial production conditions, suggests those fears may be at least partially misplaced, at least over the first decade and in the oceanic climate of southwest France. The rhizosphere emerges as the decisive arena where trees reshape vine nutrition, and soil microbes as the mediators of that influence. Longer-term monitoring, drought-year replication, and molecular tools such as metabarcoding and metagenomics will be needed to confirm the mechanisms and test the limits, but the direction of the evidence is clear: planting trees in vine rows may cultivate a healthier, more resilient soil ecosystem while the grapes keep coming.

Subject of Research: Effects of tree planting age on rhizosphere microbial activity and nitrogen nutrition of grapevines in temperate vitiforestry

Article Title: Grapevine rhizosphere microbial activity and nitrogen nutrition vary with tree planting age in a temperate vitiforestry system

Article References: Janoueix, A., Fanin, N., Milin, S., & Lauvergeat, V. (2026). Grapevine rhizosphere microbial activity and nitrogen nutrition vary with tree planting age in a temperate vitiforestry system. Plant and Soil. https://doi.org/10.1007/s11104-026-09166-3

Image Credits: AI Generated

DOI: 10.1007/s11104-026-09166-3

Keywords: vitiforestry, agroforestry, grapevine, rhizosphere, soil microbes, enzymatic activity, nitrogen status, soil organic carbon, phosphorus acquisition, eco-enzymatic stoichiometry, Bordeaux vineyard, sustainable viticulture

The story of Tribidrag is itself a tale of scientific detective work. For decades, the identity of Zinfandel was one of the great mysteries of viticulture, with competing claims about whether the variety originated in Italy, where it thrives as Primitivo, or elsewhere in the Mediterranean. Genetic fingerprinting eventually traced the cultivar to Croatia, where it survives under its oldest recorded name, Tribidrag, and where old vines still cling to terraced slopes along the Adriatic coast. Because grapevines are propagated vegetatively, by cuttings rather than seeds, every plant of a given variety is in principle a genetic copy of its parent. Yet over centuries of cloning, somatic mutations accumulate, and growers have selected vines that differ in yield, berry size, sugar accumulation, and acidity. These selected lines, called clones, are the raw material of clonal selection programs that supply nurseries and vineyards worldwide.

The research team, led by Goran Zdunić of the Institute for Adriatic Crops and Karst Reclamation in Split and including collaborators at the University of Zagreb and Yunnan Agricultural University in Kunming, set out to bridge a persistent gap in clonal research. Although previous studies had documented variation among Tribidrag clones both in the vineyard and at the molecular level, no one had systematically connected the two. The question was deceptively simple: if two clones of the same variety look and behave differently, can we find the genetic differences responsible? To answer it, the researchers evaluated productive traits in eight clones over three consecutive growing seasons, measuring yield, yield components, and basic must chemistry, the sugar and acid parameters that determine the character of the resulting wine.

The field data told a clear story of phenotypic divergence. The eight clones varied significantly in productivity and showed significant phenotypic plasticity, meaning their performance shifted from year to year depending on growing conditions. Statistical analysis revealed a significant clone-by-year interaction, confirming that no single clone dominates in every season. Two clones maintained under the Foundation Plant Services collection in California, designated FPS03 and FPS06 and known as Primitivo selections, consistently showed lower productivity, smaller berries, higher sugar content, and lower total acidity in the 2021 and 2022 seasons compared with the Zinfandel 1–24 clone. That latter clone displayed greater productivity in all three years of the study, making it the most reliable performer in the trial. For winemakers, these differences matter enormously: smaller berries with concentrated sugars tend to produce more structured, intense wines, while higher-yielding clones favor volume and freshness.

With the phenotypic landscape mapped, the team turned to the genome. Using short-read whole-genome resequencing, they generated high-coverage sequence data for each of the eight clones and called variants across the entire reference genome of grapevine. The scale of the variation was remarkable. Each sample carried approximately 3.8 million single nucleotide polymorphisms, or SNPs, which are positions where a single DNA letter differs from the reference, along with roughly 300,000 insertions and deletions, known as InDels, where short stretches of sequence are present or absent. That level of variation within a single vegetatively propagated cultivar underscores how much somatic mutation and historical mixing of plant material can accumulate over centuries of clonal transmission. Most of the structural variants were located in intergenic regions, the stretches of DNA between genes, which is consistent with the expectation that purifying selection keeps functional gene sequences relatively stable while neutral variation piles up elsewhere in the genome.

To hunt for signatures of clonal selection, the researchers took a windowed approach, dividing the genome into 100-kilobase segments and counting pairwise SNP differences among the eight clones within each window. This method highlights genomic neighborhoods where particular clones stand out from the rest, suggesting that a mutation or set of mutations arose on a specific vine lineage and was then propagated along with it. The analysis revealed candidate regions that distinguish individual clones, providing a catalog of genomic intervals that future studies can mine for genes influencing berry size, sugar transport, acid metabolism, and other traits of viticultural interest. Because the windows are small enough to pinpoint candidate loci but large enough to be robust to sequencing noise, the approach offers a practical middle ground between whole-genome association studies and targeted candidate-gene sequencing.

Then came the twist. When the researchers performed a principal component analysis on the genome-wide SNP data, the eight clones resolved into three principal genetic clusters. If clonal selection had driven the phenotypic differences, one might expect the low-yielding, sugar-rich Primitivo clones to group together genetically, apart from the productive Zinfandel selections. Instead, the genetic groupings showed no clear geographic association among the samples and, more strikingly, no direct association with the phenotypic or productive traits of individual clones. The clones that look most different in the vineyard are not necessarily the ones that are most different in their DNA, at least not at the resolution of genome-wide SNP patterns. Measurable genetic differentiation is real, but it is not a simple mirror of measurable phenotypic divergence.

This disconnect is not a failure of the study; it is arguably its most valuable finding, and it echoes a pattern seen in other clonally propagated crops. Phenotypic differences among clones can arise from a small number of mutations with large effects, from epigenetic changes such as DNA methylation that whole-genome resequencing of the kind performed here does not capture, from structural rearrangements too large or too complex for short-read sequencing to resolve, or from interactions between genotype and environment that three field seasons, however carefully measured, only begin to sample. The significant clone-by-year interaction observed in the trial reinforces this last point: the same clone can rank differently for yield and must composition depending on the season, so any attempt to link genes to traits must account for environmental noise. The candidate SNP signatures identified in 100-kilobase windows now provide a starting list of genomic regions where deeper investigation, including long-read sequencing, epigenomic profiling, and functional validation, is most likely to pay off.

For the wine industry, the implications are practical as well as scientific. Clonal selection programs rely on the assumption that the clones they distribute are genetically distinct and predictably different in performance. The new study confirms that Tribidrag clones carry abundant genomic variation and that some of it marks individual clonal lineages, which strengthens the case for DNA-based tools to authenticate and track clonal material. At the same time, the weak link between genome-wide differentiation and field performance is a caution against assuming that a genetic profile alone can predict how a clone will behave in a given vineyard. Growers choosing between the consistently productive Zinfandel 1–24 and the smaller-berry, higher-sugar Primitivo selections FPS03 and FPS06 will still need multi-season field data, but they now have a far richer genomic map to guide the search for the mutations that ultimately matter in the glass.

The work also carries a conservation message. Tribidrag survives in Croatia as a heritage cultivar of limited distribution, and the study was supported by the Croatian Science Foundation through the RemainGrape project, which is dedicated to the prospection and genomic analysis of endangered Croatian grapevine cultivars and wild grapevine. By documenting both the phenotypic richness and the genomic depth of variation within a single ancient variety, the research makes the case that preserving old vineyards and clonal collections preserves an irreplaceable archive of somatic evolution. Every century-old vine carries mutations accumulated over generations of vegetative transmission, and each clone is a living record of both natural mutation and human selection. Sequencing eight clones has revealed how much of that record remains to be read, and how much of the connection between the grapevine genome and the wine in the bottle is still waiting to be decoded.

Subject of Research: Whole-genome sequencing and phenotypic analysis of clonal variation in the grapevine cultivar Tribidrag (Zinfandel)

Article Title: Whole-genome sequencing of eight grapevine clones of cv. Tribidrag (Vitis vinifera L.) reveals measurable differentiation not linked directly to phenotypic divergence

Article References: Zdunić, G., Duan, S., Wang, C., Lukšić, K., Marinov, L., Mucalo, A., Ozretić Zoković, M., Maletić, E., Pejić, I., & Chen, W. (2026). Whole-genome sequencing of eight grapevine clones of cv. Tribidrag (Vitis vinifera L.) reveals measurable differentiation not linked directly to phenotypic divergence. BMC Plant Biology. https://doi.org/10.1186/s12870-026-10110-x

Image Credits: AI Generated

DOI: 10.1186/s12870-026-10110-x

Keywords: Tribidrag, Zinfandel, grapevine, clonal variation, whole-genome sequencing, somatic mutation, Vitis vinifera, viticulture, SNP, phenotypic plasticity, plant genetics, clonal selection

The research, led by Marta Zaffaroni and colleagues, was carried out in partnership with a French wine cooperative. Rather than asking growers to react to a finished model, the team used an action-research approach: over four workshops, cooperative managers and a multidisciplinary group of researchers sat together to design deployment strategies that were not only scientifically interesting but genuinely feasible for a real business operating a real landscape. This participatory framing matters, because deployment strategies that look optimal on paper often fail when confronted with practical constraints such as market demands, varietal identity, labor and the patchwork of plots that make up a working vineyard.

Out of those workshops came six candidate strategies for planting resistant cultivars, abbreviated RC in the study. The scenarios shared a common logic: resistant vines would replace old vines on plots more than thirty years old, which are natural candidates for replanting. Within that shared frame, the strategies differed in pace and placement. Some involved planting resistant cultivars on a fixed share of the older plots each year, set at 3.3 percent, producing a gradual rollout over decades. Others concentrated resistant vines in no-treatment zones, areas where fungicide spraying is restricted or impossible because of proximity to watercourses or human dwellings. Some scenarios also imposed a maximum percentage of resistant vines allowed in the vineyard, capping the overall share of the landscape planted with the new varieties.

To evaluate these six strategies, the team turned to the landsepi model, a simulation platform designed to capture how pathogens spread and evolve across agricultural landscapes. Landsepi treats the landscape as a mosaic of fields and tracks both the epidemiological dynamics of disease and the evolutionary dynamics of the pathogen population, including the emergence and establishment of strains capable of overcoming host resistance. The researchers implemented the strategies within the actual landscape of the cooperative, so the simulations reflected the real spatial arrangement of plots rather than an idealized grid. This landscape-scale realism is a key strength, because the spatial distribution of resistant and susceptible hosts strongly influences how quickly a pathogen can adapt.

The assessment rested on four families of criteria. The first was disease control efficacy, meaning how well each strategy kept downy mildew damage below damaging thresholds. The second was resistance durability, essentially how long the resistant cultivars remained effective before virulent pathogen strains became established. The third was the reduction in fungicide use, a central motivation for planting resistant varieties in the first place. The fourth was economic performance, evaluated both for individual vineyards and for the cooperative as a whole. By combining epidemiological, evolutionary and economic indicators, the study captured trade-offs that any single metric would have missed.

When the results were presented back to the cooperative, the managers prioritized one strategy above the rest: planting resistant cultivars in the no-treatment zones. This choice illustrates the value of the participatory process. The no-treatment strategy was not necessarily the top performer on every simulated metric, but it fit the cooperative’s broader practical constraints, including regulatory restrictions on spraying near sensitive areas. Putting resistant vines exactly where fungicides cannot be used converts an agronomic liability into an opportunity, protecting those plots genetically while leaving the rest of the landscape under conventional management.

The exercise also opened two scientific questions that have received little attention in the literature on resistance deployment. The first concerns fungicides: should growers keep spraying, even on and around resistant vines? The simulations showed that fungicide application substantially decreases the risk of resistance breakdown. Fungicides complement the epidemiological control provided by resistant cultivars, and this protective effect is particularly pronounced when the fitness costs of virulence are low, meaning the pathogen pays little penalty for evolving the ability to attack resistant plants. In that situation, reducing the pathogen population through chemical control also shrinks the evolutionary opportunity for resistance-breaking strains to emerge and spread.

The second question concerns speed: is it better to plant resistant cultivars rapidly or gradually? The simulations generally found that the probability of pathogens adapted to resistant cultivars becoming established was lower with gradual deployment than with rapid deployment. Spreading the new varieties over time keeps the landscape mosaic diverse for longer, making it harder for a specialized pathogen strain to find enough compatible hosts. However, the study uncovered a subtler and somewhat counterintuitive pattern: when adaptation did occur, the time to establishment was shorter under gradual strategies once the mean cropping ratio of resistant cultivars reached fifty percent or more. In other words, a slow rollout lowers the odds of breakdown but can accelerate it in the scenarios where breakdown happens anyway, because the resistant share of the landscape keeps climbing over time.

Perhaps the most sobering finding is that these deployment choices, despite their clear individual effects, had only a marginal overall impact on disease control. The reason lies in compensatory processes that partly cancel each other out. Dilution effects, in which resistant hosts interrupt the transmission of the pathogen among susceptible ones, improve epidemiological control as the resistant share grows. At the same time, a growing resistant share raises both the probability that a resistance-breaking strain will appear and the speed at which it establishes once it does. Rapid versus gradual deployment, spraying versus not spraying, each shift the balance between these epidemiological and evolutionary forces, but the net effect on disease levels tends to even out. This does not mean deployment strategy is irrelevant; durability and the timing of breakdown still differ between scenarios, and those differences matter to growers whose livelihoods depend on a variety remaining effective for decades.

Beyond the specific findings for viticulture, the study is a demonstration of what participatory, landscape-scale modeling can achieve. By building the scenarios with the cooperative rather than for it, the researchers ensured that the strategies were implementable, and the cooperative gained a quantitative understanding of the trade-offs behind its replanting decisions. The approach is directly transferable to other crops and other diseases where resistant cultivars are a cornerstone of integrated disease management. As agriculture seeks to reduce its reliance on fungicides, pesticides and other chemical inputs, the lesson from this French wine cooperative is that sustainable disease control is not just a breeding problem or a modeling problem. It is a design problem, best solved when the models of scientists and the knowledge of farmers are combined from the very start.

Subject of Research: Participatory landscape-scale modeling of disease-resistant grapevine cultivar deployment strategies with a wine cooperative

Article Title: Co-designing deployment strategies for disease-resistant cultivars: Insights from a participatory landscape-scale modeling study with a wine cooperative

Article References: Zaffaroni, M., Alonso Ugaglia, A., Miclot, A.-S., Rimbaud, L., Papaïx, J., Rey, J.-F., & Fabre, F. (2026). Co-designing deployment strategies for disease-resistant cultivars: Insights from a participatory landscape-scale modeling study with a wine cooperative. PLOS Sustainability and Transformation, 5(10), e0000286. https://doi.org/10.1371/journal.pstr.0000286

Image Credits: AI Generated

DOI: 10.1371/journal.pstr.0000286

Keywords: grapevine, downy mildew, resistant cultivars, resistance durability, landscape modeling, participatory research, wine cooperative, fungicide reduction, pathogen evolution, sustainable agriculture, landsepi, France

The problem the team set out to solve is deceptively simple to state and notoriously hard to execute. Accurate, objective, and scalable disease assessment underpins everything from fungicide timing to breeding decisions, but manual scouting cannot deliver it. Human evaluators differ from one another and from themselves over time; rater fatigue and variable lighting degrade consistency further; and coarse ordinal scales lack the resolution to capture subtle treatment effects. These inconsistencies ripple directly into genetics, where phenotype-to-genotype analyses depend on reliable measurements. Even when quantitative trait loci exist, noisy phenotypes can obscure them, reducing reproducibility across breeding programs. In regions like California, scouts must also peer into shaded inner canopy tissues where symptoms hide or pathogen viability is suppressed by ultraviolet light and heat.

Automated imaging systems have long promised a way out, capturing high-throughput visual data across entire vineyard blocks. But a bottleneck has persisted on the annotation side. Powdery mildew lesions are irregular, diffuse, and visually variable, making pixel-level labeling labor-intensive and dependent on scarce expert knowledge. Building large, high-quality, domain-specific datasets is prohibitively expensive, and conventional deep learning models trained from scratch on limited labeled data tend to falter in messy outdoor environments. The challenge, as the researchers frame it, is not acquiring imagery but teaching models to learn from scarce and noisy labels.

Their answer draws on the current paradigm shift in artificial intelligence from task-specific networks to generalist foundation models. The team fused two of the most influential vision foundation models: the Segment Anything Model, or SAM, trained on more than a billion masks and capable of promptable segmentation of arbitrary objects, and CLIP, a model trained on 400 million image-text pairs that aligns visual and linguistic representations in a shared embedding space. SAM contributes high-resolution spatial precision, preserving object boundaries and fine structure, while CLIP contributes semantic reasoning grounded in natural language. In the integrated architecture, each image is processed in parallel by both encoders. A learnable multilayer perceptron projects SAM’s embedding into CLIP’s latent space, the two representations are fused by element-wise addition, and the result is conditioned on text embeddings for prompts such as “Powdery mildew” or “Canopy.” A dot-product interaction between the fused visual representation and the text embedding produces a multi-modal representation that a second MLP transforms back into the spatial layout SAM’s mask decoder needs. The output is segmentation guided jointly by pixel-level detail and language-based disease concepts.

Because labeled agricultural data is scarce, the researchers systematically compared parameter-efficient fine-tuning strategies: full fine-tuning, adapter modules inserted into key layers, and low-rank adaptation, or LoRA, which updates attention and feedforward layers through small low-rank matrices. Each strategy was tested with two SAM backbones, ViT-B and ViT-H, and with either the encoder alone or both encoder and decoder trainable. The verdict was clear: adapter-based tuning with both modules trainable performed best, and the fine-tuning strategy mattered more than raw model size. LoRA’s tiny updates proved insufficient to transfer CLIP’s rich semantic knowledge into the agricultural domain, a finding that underscores how much representational capacity is needed to absorb new visual vocabulary.

The resulting models, PM-SAM-CLIP for lesion segmentation and Canopy-SAM-CLIP for canopy extraction, were trained on modest datasets collected in New York with custom imaging rigs using active strobe illumination to maximize contrast and consistency. PM-SAM-CLIP, built on the ViT-H backbone, was fine-tuned on just 175 manually annotated images; Canopy-SAM-CLIP used 415. Despite the small training sets, the models decisively outperformed baselines including PM-SAM, DeepLab v3+, and SegFormer. On the powdery mildew test set, PM-SAM-CLIP achieved 59.63 percent image-level mean intersection over union and 64.12 percent dataset-level, beating the strongest baseline by roughly 13 to 14 percentage points and weaker baselines by more than 30. Crucially, on the worst-performing subsets of images, where competing models nearly collapsed to zero, the multi-modal model maintained scores between 21.51 and 30.25 percent, demonstrating that semantic context stabilizes performance on the hardest cases, such as sparse lesions and cluttered canopies. Canopy segmentation reached 95.59 percent image-level accuracy with strong worst-case robustness.

The real test came in California, at a USDA vineyard in Parlier planted with a genetically diverse mapping population spanning multiple Vitis species and managed under a different trellis system than the New York training data. Deployed zero-shot, without any additional fine-tuning, PM-SAM-CLIP segmented infections across two growing seasons and more than 30,000 images, contending with confounders like dust and sunburn that visually mimic mildew. A post-processing step intersecting predicted infection masks with canopy masks suppressed false positives outside biologically relevant tissue. At the vine level, severity was computed as the maximum normalized overlap between infection and canopy masks across all images of each vine, mirroring how expert scouts assess the worst infection instance. The agreement with human experts was striking: 79 percent of vines in 2023 and 81 percent in 2024 received identical scores, and more than 98 percent fell within one score level of the human rating. The pipeline even captured subtleties humans cannot, such as the difference between 75 and 76 percent infected area.

The most consequential validation came from genetics. The team fed image-derived severity scores into QTL mapping using a high-density rhAmpSeq genetic map built from 465 markers across 291 progeny of a cross between Vitis amurensis and V. vinifera. Across both years, every phenotyping method, human and automated alike, converged on the same significant QTL on chromosome 13, spanning 22.2 to 27.6 megabases. That interval overlaps the previously fine-mapped REN12 locus, a known major resistance gene, providing biological confirmation that the AI-generated phenotypes capture real genetic signal. The image-derived QTL explained 22.9 to 26.2 percent of phenotypic variance, slightly below the human-scored range but well within expected field variability. Spatiotemporal heatmaps of infection across the vineyard additionally revealed persistent high-severity zones and stable low-scoring vines, information that can guide both genotype selection and site-specific fungicide decisions.

The implications extend well beyond one disease or one crop. By fine-tuning pre-trained foundation models on tiny domain datasets, the approach sidesteps the annotation bottleneck that has long constrained AI in agriculture, and text prompts give plant pathologists an interpretable way to steer model behavior using their own vocabulary. The researchers acknowledge limitations, including occasional false positives from dust and sunburn, QR-code detection failures, and the expressiveness limits of single-keyword prompts, and they point toward edge deployment on field robots, richer textual descriptions, and integration with hyperspectral or thermal sensing. They also call for open, FAIR-compliant multi-modal agricultural datasets to accelerate foundation-model training across the plant sciences. With code, models, and datasets publicly released, the study sketches a closed loop from field imagery to genotype discovery to precision disease management, a blueprint for next-generation phenotyping in viticulture and beyond.

Subject of Research: Automated phenotyping of grapevine powdery mildew using integrated SAM-CLIP multi-modal vision foundation models

Article Title: Integrating large multi-modal models for automated powdery mildew phenotyping in grapevines

Article References: Lin, Y., Dashner, Z., Jimenez, A., Wilkerson, D., Cadle-Davidson, L., Riaz, S., & Jiang, Y. (2026). Integrating large multi-modal models for automated powdery mildew phenotyping in grapevines. Artificial Intelligence in Agriculture. https://doi.org/10.1016/j.aiia.2026.09.006

Image Credits: AI Generated

DOI: 10.1016/j.aiia.2026.09.006

Keywords: powdery mildew, grapevine, phenotyping, SAM, CLIP, foundation models, segmentation, QTL mapping, viticulture, plant disease detection, multi-modal AI, breeding

Researchers loaded gibberellic acid into biodegradable polymeric nanoparticles and applied the formulation to grapevines in field trials. Compared with conventional applications of the free hormone, the nanoparticle treatment increased grape cluster weight by 104 percent and cluster length by 67 percent. At the level of individual berries, the gains were more modest but still meaningful: berry weight rose by 15 percent, berry length by 4 percent, and berry width by 13 percent. In an industry where cluster size and berry uniformity translate directly into market value, improvements of this magnitude are far from trivial.

The logic behind the approach draws on one of the most active frontiers in agricultural science: controlled-release delivery systems. Nanocarriers, typically built from biodegradable polymers, act as microscopic protective shells that encapsulate active ingredients and release them gradually as the polymer matrix breaks down. This serves two purposes at once. First, it shields sensitive molecules like gibberellic acid from the environmental stressors, principally ultraviolet radiation and elevated temperatures, that would otherwise destroy them. Second, it extends the window of biological activity, so the plant receives a steadier supply of the hormone rather than a single pulse that fades within hours.

As the study’s authors put it, nanocarrier systems ensure more efficient delivery of active substances such as plant growth regulators compared with traditional products. That efficiency matters for reasons that go beyond yield. When a large fraction of an applied agrochemical degrades or drifts before it can act, growers must compensate by applying more, which raises costs and increases the chemical load entering soil and waterways. A delivery system that keeps more of the active ingredient biologically available for longer allows lower doses to achieve the same or better agronomic outcomes, a central goal of sustainable intensification in farming.

Gibberellic acid itself has a storied history in crop science. Identified in the mid-twentieth century as the compound behind the so-called foolish seedling disease of rice, in which infected plants grow abnormally tall, the gibberellin family of hormones was quickly harnessed for agriculture. Today, manufactured gibberellic acid is used worldwide to enlarge grapes, particularly seedless table varieties, to promote malting in barley, to trigger flowering in some crops, and to improve fruit set under unfavorable conditions. In viticulture, its ability to loosen and elongate grape clusters also has a practical side: less densely packed clusters dry faster after rain and are less prone to fungal rot.

What makes the new findings notable is that they were demonstrated under real field conditions rather than in the greenhouse or laboratory, where nano-delivery research often stalls. Translating laboratory formulations into agronomic practice is notoriously difficult. Field environments expose nanoparticles to rain, wind, temperature swings, and microbial communities that can alter their stability and release behavior. Demonstrating that a biodegradable nanocarrier can outperform the conventional formulation in a working vineyard is therefore a significant step toward practical adoption, and it provides a template that could be adapted to other plant growth regulators and crop systems.

The choice of a biodegradable polymer carrier is also significant for the environmental calculus. Unlike some engineered nanomaterials that raise questions about persistence and accumulation in soils, biodegradable polymers are designed to break down into naturally occurring degradation products, limiting long-term residue concerns. This aligns with the broader push in agricultural technology toward materials that perform their function and then disappear. If nano-encapsulation allows growers to use less active ingredient per hectare while achieving larger yield responses, the combined effect could be a genuine reduction in the chemical footprint of high-value horticulture.

The reported effects on berry dimensions and cluster architecture hint at the underlying physiology. Gibberellins promote cell elongation and division, and in grapes this manifests as larger berries and elongated clusters. By maintaining a sustained presence of the hormone at the plant surface and in the vascular system, the nanoparticle formulation appears to have amplified these developmental programs beyond what a single conventional spray can achieve. The study’s authors also report enhancements related to pedicel strength, the structural connection between berry and stem, which influences how well fruit holds on the vine through harvest, an attribute with direct implications for handling and shelf life.

For the grape industry, the implications are immediate and tangible. Table grapes compete in global markets on appearance, size, and uniformity, and growers invest heavily in plant growth regulator programs to meet exacting retail standards. A delivery technology that more than doubles the cluster weight response of the same active ingredient could reshape those programs, reducing both input costs and the number of applications needed through a season. Wine grape production, where cluster compactness and berry size are managed more delicately, could also benefit from the precision that controlled-release systems offer, allowing targeted interventions without the overshoot that conventional sprays sometimes produce.

More broadly, the study adds to a growing body of evidence that nanotechnology, often associated with electronics and medicine, has a serious role to play in feeding a changing world. Encapsulation platforms are being explored for fertilizers that release nutrients on demand, for pesticides that target pests with less collateral exposure, and for the delivery of biologicals such as beneficial microbes and RNA-based crop protection agents. The present work, published with the article title Polymeric Nano-Delivery of Gibberellic Acid Enhances Fruit Quality, Yield, and Pedicel Strength in Grapevine (Vitis vinifera L.), stands out because it pairs a fully biodegradable carrier with a natural plant hormone and validates the combination in the field. As the authors suggest, nanocarrier systems represent a promising and environmentally friendly route to sustainable agricultural production, and if subsequent studies replicate these yield gains across seasons, regions, and crops, the humble nanoparticle may soon become as standard a tool in the orchard and vineyard as the sprayer itself.

Subject of Research: Biodegradable polymeric nanoparticle delivery of gibberellic acid to improve grapevine yield and quality

Article Title: Biodegradable nanoparticle–technology may improve agricultural production

Article References: Biodegradable nanoparticle–technology may improve agricultural production. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: gibberellic acid, nanoparticles, biodegradable polymers, grapevine, plant growth regulators, sustainable agriculture, nano-delivery, crop yield, fruit quality, Vitis vinifera, agricultural nanotechnology, Biodegradable

The research team set out to answer a question that has long frustrated plant pathologists and viticulturists alike: why do some grapevine cultivars tolerate infection by trunk disease fungi while others succumb, even though no grapevine genotype is fully resistant? Tolerance in this context is measured by the expression of foliar symptoms, which varies considerably among cultivars, yet the biochemical mechanisms underlying this variation have remained poorly understood. To probe the question, the researchers chose two cultivars with well-documented contrasting responses to Botryosphaeria dieback: Chardonnay, which shows greater tolerance, and Gewurztraminer, which is more susceptible. By comparing how these two cultivars reconfigure their chemistry after infection, the team hoped to identify the metabolic signatures that separate a resilient vine from a vulnerable one.

The experimental design was ambitious in scope. Rather than examining only the infection site in the woody stem, as most earlier studies have done, the researchers conducted whole-plant metabolomic analyses, sampling wood, leaves and roots at different times after inoculation. They used untargeted liquid chromatography coupled with mass spectrometry, a technique that allows scientists to detect and measure thousands of small molecules simultaneously without knowing in advance which ones will prove important. This unbiased approach is critical when studying complex plant-pathogen interactions, because defense chemistry often involves unexpected compounds and pathways that a targeted analysis would miss entirely.

A key feature of the study was the use of two different N. parvum isolates that differ in aggressiveness. Pathogen colonization assays confirmed that the two isolates possessed contrasting wood invasion capacities, with one spreading more extensively through the host tissue than the other. This distinction mattered: it allowed the researchers to separate the effects of the plant cultivar from the effects of the fungal strain, revealing that the outcome of infection depends on the specific pairing of host and pathogen rather than on a generic interaction between grapevine and wood-decay fungus. The two isolates used in the work were designated Np.Bt67 and Np.Bourgogne, and their differing behavior in the wood provided a natural experiment in fungal virulence.

When the team analyzed the resulting metabolomic data using principal component analysis, a statistical method that reveals the dominant sources of variation in large datasets, a clear pattern emerged. The cultivar of the vine and the identity of the fungal isolate were the main factors structuring metabolic variation across the experiment, with additional contributions from the organ being sampled and the time elapsed since inoculation. In other words, the chemical state of a vine after infection is not determined by the fungus alone or the plant alone, but by the interplay between a particular cultivar and a particular fungal isolate, modulated by where in the plant one looks and how long the infection has had to develop.

The most striking differences appeared in the wood, the primary battleground between vine and pathogen. In response to the most aggressive isolate, the two cultivars mounted clearly distinct metabolic responses, particularly in their profiles of stilbenes and oxylipins. Stilbenes are a family of phenolic compounds, including the famous resveratrol, that grapevines synthesize as antifungal weapons, and their production is governed by enzymes such as stilbene synthase and the upstream phenylalanine ammonia-lyase, both central players in plant defense. Oxylipins, by contrast, are oxygenated derivatives of fatty acids produced through the lipoxygenase pathway, and they serve as both antimicrobial compounds and signaling molecules that coordinate defense responses across the plant.

Here the tolerant cultivar revealed its hand. Compared with Gewurztraminer, Chardonnay showed a faster and stronger induction of stilbene and fatty acid synthesis in its wood, especially of oxylipins, compounds that could be involved in both direct defense and long-distance signaling. This rapid chemical mobilization suggests that the tolerant vine does not simply produce more of the right compounds at the end of the battle; it activates its defensive chemistry earlier and more vigorously, potentially slowing the pathogen before it can establish a firm foothold. Notably, the study found that pathogen growth was similar between the two cultivars, meaning that the difference in tolerance cannot be explained by the fungus simply growing more slowly in Chardonnay. Instead, the two cultivars are characterized by specific metabolite signatures, especially in the wood, pointing to fundamentally different interaction mechanisms rather than a common response to wood decay.

Perhaps the most surprising finding came from beyond the infection site. The researchers observed that leaves and roots also exhibited early metabolic adjustments after the fungus was introduced into the wood, and these systemic changes were more pronounced in Chardonnay than in Gewurztraminer. This indicates that the tolerant cultivar mounts a rapid whole-plant response, reprogramming its metabolism far from where the pathogen is actually attacking. Such systemic metabolic reprogramming may reduce the overall impact of infection on host tissues, priming distant organs to cope with the physiological disruption that trunk disease causes as it progresses. The finding challenges the conventional focus on the wood alone and suggests that the fate of an infected vine is decided, in part, by how quickly the entire plant can reorganize itself.

The broader implications of this work extend into viticulture and breeding. Grapevine trunk diseases are increasingly concerning in the context of climate change, and with no fully resistant genotypes available, growers currently rely on costly and labor-intensive management practices, including the surgical removal of infected wood and the replanting of dead vines. Understanding the metabolic basis of tolerance could eventually help breeders select for cultivars with the rapid stilbene and oxylipin responses seen in Chardonnay, or guide the development of treatments that stimulate these pathways in susceptible varieties. The study also underscores that fungal isolate matters as much as host cultivar, which means that breeding and protection strategies may need to account for the local diversity of Botryosphaeriaceae populations in vineyards.

By integrating pathogen colonization data with untargeted metabolomics across three organs, two cultivars, two fungal isolates and multiple time points, the research provides a more integrated view of grapevine responses to Botryosphaeriaceae infection than has previously been available. The work, conducted at the Université de Haute Alsace with plants supplied by INRAE UMR SVQV in Colmar, France, and supported by the French Ministry of Higher Education and Research, demonstrates that tolerance to trunk disease is not a single trait but a dynamic, system-wide chemical performance. As vineyards face mounting pressure from a warming climate and evolving pathogen communities, studies like this one bring the field closer to understanding why some vines endure what destroys others, and how that resilience might one day be engineered or bred into the varieties the wine world depends on.

Subject of Research: Metabolomic responses of tolerant and susceptible grapevine cultivars to infection by the trunk disease fungus Neofusicoccum parvum

Article Title: Whole plant metabolomic analysis reveals contrasted responses in tolerant and susceptible grapevine cultivars to infection with different isolates of Neofusicoccum parvum, a major trunk disease fungus

Article References: Grau, A. L., Lacrampe, N., Goddard, M.-L., & Chong, J. (2026). Whole plant metabolomic analysis reveals contrasted responses in tolerant and susceptible grapevine cultivars to infection with different isolates of Neofusicoccum parvum, a major trunk disease fungus. BMC Plant Biology. https://doi.org/10.1186/s12870-026-09951-3

Image Credits: AI Generated

DOI: 10.1186/s12870-026-09951-3

Keywords: grapevine, Neofusicoccum parvum, Botryosphaeria dieback, grapevine trunk diseases, metabolomics, stilbenes, oxylipins, plant defense, Chardonnay, Gewurztraminer, fungal pathogen, viticulture

The study was conducted in 2024 at the Tekirdağ Viticulture Research Institute, in a rainfed vineyard whose elevation ranges from roughly 47.45 to 55.46 meters above sea level. The researchers divided the block into three slope positions—lower, middle, and upper—and examined vines grafted onto 5BB rootstock and trained in a bilateral cordon system. Because the vineyard receives no irrigation, every vine depends entirely on rainfall and soil water reserves, making the site a natural laboratory for observing how water availability, which typically declines upslope, translates into physiological and biochemical change.

Across the growing season, the team measured net photosynthesis, stomatal conductance, transpiration, and two measures of water use efficiency on eleven separate occasions, under climatic conditions spanning air temperatures of 30 to 38 degrees Celsius, relative humidity of 26 to 50 percent, and photosynthetically active radiation from 600 to 1800 micromoles per square meter per second. These repeated field measurements captured how the vines responded to genuinely fluctuating Mediterranean summer conditions rather than a single snapshot, giving the dataset unusual ecological realism for a physiological study.

The results revealed a clear stress gradient running up the hill. Vines at the upper slope position showed lower rates of photosynthesis and stomatal conductance than their lower-slope counterparts, but they achieved higher water use efficiency—both in terms of carbon gained per unit of water lost through stomata and per unit transpired. In other words, the upslope vines were running a conservative water-use strategy, keeping their stomata tighter to conserve moisture at the cost of slower carbon assimilation. This is a classic drought-avoidance signature, and its emergence along a purely topographic gradient underscores how strongly slope position governs vine water status even within a single, seemingly uniform vineyard.

Biochemical analyses reinforced the physiological picture. Chlorophyll a, chlorophyll b, and total chlorophyll contents all decreased as one moved upslope, consistent with stress-impaired pigment metabolism, while the ratio of chlorophyll a to b increased—a shift often associated with acclimation to harsher light and water conditions. Meanwhile, the stress-signaling hormone abscisic acid, total phenolics, and tannins all rose with slope position. Abscisic acid is the plant hormone that orchestrates stomatal closure under drought, so its upslope accumulation dovetails neatly with the observed reduction in stomatal conductance and the shift toward water conservation.

Perhaps the most striking results came from high-performance liquid chromatography profiling of individual phenolic compounds. Gallic acid, vanillic acid, syringic acid, caftaric acid, chlorogenic acid, caffeic acid, catechin, epicatechin, rutin, and kaempferol all accumulated more abundantly in vines at the middle and upper slope positions. These compounds are not merely metabolic byproducts; they form a chemically diverse defensive shield, scavenging reactive oxygen species generated when photosynthesis is stressed, reinforcing cell walls, and deterring pathogens. Their upslope enrichment suggests that vines facing tighter water budgets invest more heavily in secondary metabolism, effectively trading growth and carbon gain for chemical resilience.

To test whether these patterns were statistically robust rather than incidental, the researchers applied principal component analysis and hierarchical clustering to the full dataset. Both multivariate approaches cleanly separated the three slope positions, with the upper slope clustering alongside the key stress markers—elevated abscisic acid, phenolics, tannins, and water use efficiency, and depressed chlorophyll and photosynthesis. Bivariate correlation analysis added a further layer: photosynthesis was negatively linked with abscisic acid, intrinsic water use efficiency, and phenolic concentrations, exposing an explicit trade-off between carbon assimilation and defense investment. A vine cannot maximize both at once, and the slope dictates where along that continuum each plant sits.

Proline, a compatible osmolyte that helps cells maintain turgor under water deficit, was also measured, along with antioxidant capacity assessed by the TEAC assay. Together with the hormone and pigment data, these measurements sketch a coherent portrait of ‘Adakarası’ as a cultivar with genuine drought resilience. Rather than collapsing under upslope stress, the vines reprogrammed their physiology and secondary metabolism in an apparently coordinated fashion—closing stomata, signaling with abscisic acid, accumulating osmoprotectants, and ramping up phenolic defenses. Such integrated plasticity is precisely the trait profile that breeders and growers seek as climate zones for quality viticulture shift poleward and upward.

The work also speaks to the concept of terroir, the oft-invoked idea that place imprints itself on wine. While terroir is usually discussed in terms of soil, mesoclimate, and tradition, this study demonstrates that within-vineyard topography alone can generate measurable gradients in leaf chemistry and gas exchange. Slope-driven differences in soil water content, erosion, and solar exposure appear sufficient to push vines into distinct physiological and metabolic states—states that plausibly influence berry composition and, ultimately, wine character. For precision viticulture, the message is that slope position deserves attention not just at the scale of hillsides and valleys, but within individual blocks.

For the Turkish wine industry, the stakes are concrete. ‘Adakarası’ is a heritage variety native to Thrace, and preserving its cultivation under a warming, drying climate depends on understanding where it thrives and why. By identifying the upper slope as a zone of conservative water use and heightened phenolic defense, and the lower slope as one of freer gas exchange, the study offers growers a physiological rationale for vineyard design, rootstock and scion matching, and future irrigation decisions. More broadly, it shows that a humble hillside, read carefully through the language of pigments, hormones, and polyphenols, can teach us how one of humanity’s oldest crops negotiates the stress of a changing world.

Subject of Research: Slope-induced abiotic stress effects on leaf phenolics and physiological activity in the grapevine cultivar Vitis vinifera 'Adakarası'

Article Title: Leaf phenolics, physiological activity and abiotic stress relationship induced by slope in grapevine: Vitis vinifera ‘Adakarası’

Article References: Candar, S., Alço, T., Seçkin, G. U., Şahin, E., Demirağ, O., Güngör, T. A., Bahar, E., & Korkutal, İ. (2026). Leaf phenolics, physiological activity and abiotic stress relationship induced by slope in grapevine: Vitis vinifera ‘Adakarası’. Plant Biosystems, 160(4), Article 217. https://doi.org/10.1007/s44473-026-00228-z

Image Credits: AI Generated

DOI: 10.1007/s44473-026-00228-z

Keywords: grapevine, Vitis vinifera, Adakarası, drought stress, phenolic compounds, abscisic acid, photosynthesis, water use efficiency, chlorophyll, slope gradient, viticulture, climate change

The research team, led by Yuanqian Ni and supervised by Zhaosen Xie and Youmei Li, took advantage of a natural contrast between two grapevine cultivars. ‘Einset Seedless’, abbreviated ENT in the study, tends to produce inflorescences at the lower tendril nodes of its lateral shoots, while ‘Pinot Noir’, or PN, overwhelmingly produces true tendrils at the equivalent positions. By comparing these two varieties node by node, the researchers could ask a precise question: when the same meristem faces the same choice, what is different inside the cells of a plant that flowers versus a plant that climbs?

The homology of tendrils and inflorescences in grapevine is well established. Classical anatomical work showed that both organs arise from the same uncommitted primordia on lateral shoots, and earlier molecular studies found that floral meristem identity genes are expressed even in developing tendrils, as if the tendril were an inflorescence that never quite committed to flowering. Decades ago, pioneering experiments by Srinivasan and Mullins demonstrated that isolated tendrils could even be coaxed into forming inflorescences in vitro, hinting that the switch between the two fates is chemically malleable. What the new study adds is a genome-wide, node-resolved map of the transcriptional landscape in which that switch is thrown.

The team first quantified the anatomical difference, confirming that ENT achieved a markedly higher flowering rate at tendril nodes one through four than PN did. They then harvested tissue from specific tendril nodes in both cultivars and performed RNA sequencing, using an intersection and exclusion strategy to isolate 549 differentially expressed genes that distinguish inflorescence-prone from tendril-prone tissue. When those genes were subjected to Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis, two signaling systems rose to the top: plant hormone signal transduction and mitogen-activated protein kinase cascades. In other words, the decision between flower and tendril appears to be broadcast through the cell by hormonal and phosphorylation-based communication channels rather than by a single master switch.

To move beyond a static snapshot, the researchers applied Mfuzz clustering, a computational method that groups genes according to the shape of their expression trajectories across a developmental series. This revealed that multiple expression programs rise and fall in patterns that track the flowering gradient running along the shoot, from the most inflorescence-prone basal nodes to the tendril-dominated upper nodes. Across every dynamic cluster, plant hormone signal transduction emerged as the predominantly enriched pathway, underscoring that phytohormones are not merely participants in this process but sit at its very center.

Guided by that transcriptional evidence, the team measured the endogenous levels of two key hormones directly in the nodal tissues: zeatin, the classic cytokinin that generally promotes reproductive meristem activity and flowering, and gibberellin GA3, which is more often associated with stem elongation and vegetative growth. The striking result was that the ratio between the two, rather than the absolute level of either hormone alone, paralleled the flowering gradient across nodes and correlated with the gene expression trajectories identified by clustering. A high zeatin-to-GA3 ratio accompanied the inflorescence-prone state, while a lower ratio accompanied tendril formation. This provides concrete physiological support for a cytokinin-gibberellin interaction model in which the balance between these two antagonistic hormones helps determine whether a lateral meristem matures into a flower-bearing branch or an elongating, climbing tendril.

The hormone story dovetails with a long history of viticultural observation. Growth retardants that suppress gibberellin synthesis have been known since the 1960s to influence fruitfulness in grapes, and cytokinin treatments have been shown to convert tendril primordia into inflorescences, with the success of that conversion depending on the genotype. The famous ‘green revolution’ dwarfing mutation in grapevine, which links reduced gibberellin response with enhanced floral induction, fits the same pattern. What the new transcriptomic work contributes is the mechanistic scaffolding: it shows that the endogenous hormone ratio in the organ itself, not just externally applied chemicals, tracks the developmental outcome, and that the downstream transcriptional response is organized into coherent, flowering-correlated trajectories.

Within the pool of differentially expressed transcription factors, one gene stood out. A MADS-box gene named FRUITFULL-LIKE, or VvFUL-L, was markedly upregulated in PN tendrils compared with inflorescence-prone ENT tissue. MADS-box transcription factors are the celebrated architects of floral development, and the FRUITFULL lineage in particular is known from arabidopsis and tomato to regulate meristem identity, flowering time, and inflorescence architecture. To probe what VvFUL-L might be doing, the team overexpressed it heterologously in arabidopsis. The transgenic plants flowered earlier than normal and produced inflorescences with reduced branching, phenotypes consistent with a role in steering lateral meristem development. The authors suggest that VvFUL-L may help tip the uncommitted grapevine lateral meristem toward the tendril program, although confirming that function in grapevine itself will require further work in the crop.

The agronomic implications are immediate and tangible. Excessive tendril growth increases vineyard management costs because tendrils must be removed or redirected by hand or machine, and they can girdle shoots and interfere with canopy machinery. If the cytokinin-to-gibberellin ratio and regulators like VvFUL-L can be manipulated, whether through breeding, targeted gene editing, or growth regulator programs, growers could eventually favor inflorescence formation at the basal nodes where fruit is wanted and suppress the runaway tendril production that wastes the vine’s resources. The study’s authors frame their findings as a foundation for future molecular and breeding studies aimed at managing tendril growth, and the identification of a small set of hormone-responsive genes and a candidate transcriptional regulator is exactly the kind of entry point such efforts require.

There is also a broader evolutionary resonance in the result. Across the grape family, the Vitaceae, tendrils and inflorescences are thought to be variations on a single ancestral organ, and expression studies of APETALA1, FRUITFULL, FLOWERING LOCUS T, and LEAFY orthologs throughout the family support that homology. The Yangzhou study now supplies a quantitative, node-by-node account of how that shared developmental potential is partitioned within a single plant, showing that the fate of each primordium is written in the language of hormone ratios and read out by MADS-box transcription factors. A curling tendril on a Pinot Noir vine, in this light, is not a failed flower but an alternative interpretation of the same instructions, and researchers are learning to read, and perhaps one day to rewrite, the grammar behind that choice.

Subject of Research: Molecular regulation of tendril versus inflorescence development in grapevine lateral shoots

Article Title: Comparative transcriptomics reveals hormone signaling and MADS-box genes in divergent development of inflorescences and tendrils in grapevine lateral shoots

Article References: Ni, Y., Bian, Y., Xie, Z., & Li, Y. (2026). Comparative transcriptomics reveals hormone signaling and MADS-box genes in divergent development of inflorescences and tendrils in grapevine lateral shoots. Plant Cell Reports, 45(9), Article 270. https://doi.org/10.1007/s00299-026-03957-9

Image Credits: AI Generated

DOI: 10.1007/s00299-026-03957-9

Keywords: grapevine, Vitis vinifera, tendrils, inflorescences, cytokinin, gibberellin, MADS-box, VvFUL-L, transcriptomics, hormone signaling, flowering, viticulture