The research team combined several powerful sequencing technologies to compare two kinds of eucalyptus leaves: ordinary green leaves and anthocyanin-rich red leaves. Using PacBio full-length transcriptome sequencing, a method that reads RNA molecules from end to end rather than in fragments, they captured 25,953 high-quality transcripts from green leaves and 32,821 from red leaves. This long-read approach matters because it allows scientists to see entire RNA molecules, including the subtle variations that shorter-read methods often stitch together incorrectly or miss entirely. Alongside this, the team performed standard RNA sequencing to measure how abundantly each transcript was produced in the two leaf types.

The scale of hidden diversity they uncovered was remarkable. Of the transcripts they identified, 10,766 in green leaves and 11,637 in red leaves represented novel isoforms of genes that had already been annotated in the eucalyptus genome. In other words, a substantial fraction of the tree’s RNA output consists of versions of known genes that had never been catalogued before. The primary engine of this diversity was alternative splicing, the process by which a single gene’s RNA copy is cut and reassembled in different ways to produce multiple distinct messenger RNAs, each of which can potentially encode a different protein or carry different regulatory properties.

Alternative splicing is well known in animals, where it allows a limited set of genes to generate an enormous range of proteins, but its role in plants, and in plant pigment biology specifically, has received far less attention. What makes the new study particularly intriguing is its finding that most of the structural genes involved in anthocyanin biosynthesis, the enzyme-coding genes that chemically build the pigment step by step, each produced multiple alternatively spliced isoforms. This pattern suggests that the splicing machinery is not simply noise; it may be an active regulatory mechanism that fine-tunes how much pigment a leaf produces, or when and where it produces it, depending on the circumstances the tree faces.

Turning from the structural genes to their controllers, the researchers searched the transcriptome for transcription factors, the DNA-binding proteins that switch genes on and off, with links to flavonoid biosynthesis, the broader chemical pathway to which anthocyanins belong. They identified twelve MYB genes as candidates. The MYB family is one of the largest families of transcription factors in plants, and members of a particular subgroup, including the well-studied MYB113 gene, are famous master switches that activate entire suites of anthocyanin biosynthesis genes at once. Among the twelve candidates, the team found three homologs of MYB113, which they named MYB113a, MYB113b, and MYB113c.

The three homologs did not behave identically. When the researchers exposed the plants to different environmental and hormonal cues, including cytokinin, a plant hormone involved in growth and development; varying levels of nitrogen, a nutrient whose scarcity often triggers pigment production; and high-light treatment, a classic stress that induces anthocyanin accumulation, each MYB113 gene responded with its own distinct expression pattern. This divergence implies that the three genes have specialized over evolutionary time, potentially allowing the tree to deploy pigment production in response to different combinations of signals rather than a single generic stress response.

One of the three stood out for an unexpected reason. MYB113c showed relatively low sequence similarity to MYB113 genes that had been functionally characterized in other plant species, raising the question of whether it truly worked as an anthocyanin regulator at all. To answer this, the team carried out functional analyses in both eucalyptus itself and in tobacco, a widely used experimental plant that serves as a convenient testing ground for gene function. The outcome was clear: despite its unusual sequence, MYB113c acts as a positive regulator of anthocyanin accumulation, promoting the buildup of the red pigment when it is active. This finding expands the known repertoire of anthocyanin switches and suggests that sequence-based predictions alone can miss functional regulators in less-studied tree genomes.

The broader significance of the work lies in how it connects two levels of gene regulation. On the transcriptional level, the study identifies specific MYB113 genes that respond to environmental signals and likely drive the expression of pigment-building enzymes. On the post-transcriptional level, it reveals that the very genes in the anthocyanin pathway are extensively reshaped by alternative splicing, adding a layer of control that operates after a gene has been switched on. Together, these layers may explain how eucalyptus achieves precise, condition-dependent control over a metabolically costly process like pigment production, producing anthocyanins only when the protective benefit outweighs the expense.

For plant scientists, the study provides a rich catalog of full-length transcripts and novel isoforms in a genus of enormous ecological and economic importance. Eucalyptus plantations cover vast areas of the tropics and subtropics, supplying timber, paper pulp, and oils, and the trees’ responses to stress are of direct practical concern. Understanding which regulators link environmental cues to anthocyanin accumulation could eventually inform breeding programs aimed at producing trees better equipped to handle high light, drought, or poor soils, or even ornamental varieties with enhanced red coloration.

For the wider public, the study is a reminder that a splash of red in a forest canopy is the visible tip of an intricate molecular process. A single gene can yield many RNA messages; a family of related switches can each listen for different signals; and a tree integrates all of this information to decide whether its leaves should stay green or turn red. The Guangxi University team’s work, published open access so that anyone can read the full details, shows that even in a well-studied group of plants, fundamental discoveries about how genes are read, spliced, and regulated are still waiting to be made, one full-length RNA molecule at a time.

Subject of Research: Transcriptional and post-transcriptional regulation of anthocyanin biosynthesis by MYB113 genes in Eucalyptus

Article Title: Transcriptional and post-transcriptional insights into MYB113-associated anthocyanin regulation in Eucalyptus

Article References: Zeng, Z., Tang, Y., Liao, Y., Lin, K., Ye, K., Xu, Z.-F., & Ni, J. (2026). Transcriptional and post-transcriptional insights into MYB113-associated anthocyanin regulation in Eucalyptus. BMC Plant Biology. https://doi.org/10.1186/s12870-026-10027-5

Image Credits: AI Generated

DOI: 10.1186/s12870-026-10027-5

Keywords: Eucalyptus, anthocyanin, MYB113, alternative splicing, transcriptomics, PacBio sequencing, flavonoid biosynthesis, transcription factors, plant stress response, cytokinin, nitrogen, high light

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

The two most intensively studied feeding structures are giant cells and syncytia, and their developmental strategies could hardly be more different. Root-knot nematodes induce giant cells through rounds of mitosis that lack cytokinesis, combined with repeated endoreduplication, producing enlarged, multinucleate cells stuffed with dense cytoplasm. These cells develop wall ingrowths resembling xylem transfer cells, dramatically increasing the plasma membrane surface area available for solute exchange. Cyst nematodes, by contrast, dissolve the cell walls of neighboring root cells and fuse their protoplasts into a syncytium, a single continuous multinucleate compartment that can eventually encompass more than two hundred cells. Remarkably, three-dimensional reconstructions have shown that individual giant cells can expand roughly sixty-fold in volume between three and forty days after infection, a transformation driven by cell wall loosening and continuous cytoskeletal rearrangement.

None of this happens by accident. The engine of the entire process is the nematode’s stylet, a hollow, protrusible spear connected to esophageal gland cells that secrete a cocktail of effector proteins directly into host tissue. These effectors include cell wall-degrading enzymes such as cellulases, hemicellulases, and pectinases that ease penetration and migration, but the more intriguing molecules are those that manipulate host physiology from within. Once inside plant cells, effectors travel to the nucleus, the cytoplasm, or the apoplast, where they bind host proteins and bend gene expression to the parasite’s advantage. In compatible interactions, the host’s normal developmental pathways are subverted: the cell cycle is reactivated, cell wall architecture is remodeled, and metabolism is redirected toward feeding site construction.

Plant hormones sit at the center of this manipulation. Local auxin accumulation is a master switch for feeding site formation, and nematodes have evolved multiple ways to boost it. The cyst nematode effector 19C07 interacts with the auxin influx transporter LAX3 to enhance auxin flow into selected cells and upregulate cell wall-degrading enzymes, while the effector 10A07 binds the auxin response repressor IAA16, destabilizing its suppressive grip on auxin response factors and even recruiting a host kinase, IPK, to shepherd it into the nucleus. Cytokinin plays an equally critical role in driving cell cycle reactivation at the G1/S transition. Strikingly, Heterodera schachtii carries its own isopentenyltransferase gene, effectively synthesizing cytokinin from the parasite’s side of the interface; silencing that gene suppresses feeding site expansion, and Arabidopsis mutants lacking the cytokinin receptors AHK3 and AHK4 show markedly reduced susceptibility. Ethylene plays a double game, sometimes attracting nematodes to roots and promoting syncytial cell wall expansion, yet also capable of reducing infection through interactions with the receptor ETR1, a contradiction the review flags as an open question.

At the same time, nematodes must dismantle the plant’s immune system, which operates in two layers. Pattern-triggered immunity begins when cell surface receptors detect pathogen-associated molecular patterns, triggering reactive oxygen species production, MAP kinase cascades, and cell wall reinforcement. A deeper layer, effector-triggered immunity, mediated by intracellular resistance proteins, produces localized cell death that starves the parasite. Nematode effectors attack both layers with surgical precision. In rice, the Meloidogyne graminicola effector MgMO237 suppresses pattern-triggered immunity by binding multiple defense-related host proteins, while MgMO289 manipulates the host’s reactive oxygen system through the copper metallochaperone OsHPP04. The M. javanica effector MjTTL5 recruits the thioredoxin reductase subunit AtFTRc to scavenge ROS during the oxidative burst, and the sugar beet cyst nematode effector 10A06 targets spermidine synthase 2 to bolster antioxidant capacity at the infection site. In Globodera rostochiensis, the ubiquitin carboxyl extension protein GrUBCEP12 suppresses flg22-induced immunity, and the effector Gr29D09 disables the potato hexokinase StHXK1.

The review devotes particular attention to transcription factors, the master regulators that nematodes either hijack or exploit as part of the plant’s own response. Functional studies in Arabidopsis and tomato have identified fifteen co-regulated transcription factor hubs during infection, spanning the MYB, WRKY, and ARF families. One especially revealing case is DEL1, an atypical E2F factor that suppresses salicylic acid accumulation and lignin biosynthesis during root-knot infection by repressing EDS5, a gene encoding a salicylic acid transporter. del1 mutants accumulate more salicylic acid, lignify their galls more heavily, and resist infection, while the nematode’s own effector Mi-ISC-1 independently attacks the isochorismate pathway that feeds salicylic acid synthesis. The convergence of host and parasite manipulation on the same pathway underscores how central it is to the outcome of infection.

The WRKY family illustrates the bewildering duality of transcriptional control in these interactions. WRKY11 and WRKY17 act as positive defenders in Arabidopsis, with mutants of either gene showing heightened susceptibility to both cyst and root-knot nematodes. Yet in tomato, SlWRKY16 and SlWRKY31 behave as negative regulators, and their overexpression enhances infection while suppressing defense-related genes. SlWRKY45 goes further: it interacts with JAZ repressor proteins and, once released, binds the promoter of the jasmonic acid biosynthesis gene AOC, throttling jasmonate production and opening the door to the parasite. Meanwhile, WRKY23 promotes feeding site formation by inducing auxin-responsive genes, and bHLH25 and bHLH27 act synergistically to support syncytium development in cyst nematode infection. The same family can thus contain both shields and traitors, and which role a given member plays depends on species, tissue, and developmental stage.

Effectors also reach deep into the plant’s information-processing machinery. The M. incognita effector Mi16D10 binds SCARECROW-like GRAS transcription factors to accelerate giant cell formation, and Mi2G02 hijacks the trihelix factor GT-3a, converting it into a transcriptional inhibitor that silences cell development genes through the 26S proteasome pathway. The cyst nematode effector 30D08 targets AtSMU2, a spliceosome component, perturbing pre-mRNA splicing across thousands of transcripts, and MiEFF18 attacks the core spliceosomal protein SmD1 to fine-tune transcripts governing the cell cycle and cytoskeleton. Indeed, root-knot nematodes induce splicing reprogramming of roughly 2,898 genes involving more than 9,065 transcripts during gall formation. Beyond transcription, epigenetic mechanisms add another layer of control: DNA hypomethylation occurs early in infection, potentially activating stress genes, while the effector Hs32E03 interacts with the histone deacetylase HDT1 to alter acetylation patterns in ribosomal DNA regions, reshaping chromatin to favor parasitism.

What makes the review compelling is its translational ambition. The authors argue that understanding these molecular vulnerabilities opens concrete routes to resistance: CRISPR/Cas editing of transcription factors that mediate feeding site formation, breeding informed by epigenetic marks associated with defense, and host-induced gene silencing that knocks out essential nematode effectors. They also champion single-cell and single-nucleus RNA sequencing as the next frontier, since bulk transcriptomics averages away the cellular heterogeneity that defines galls and syncytia, and functional redundancy among transcription factors often masks the effect of silencing any single gene. Gland-cell-specific transcriptomics is meanwhile expanding the catalog of known effectors, offering a moving target that breeders and biotechnologists must track.

The bigger picture is one of an evolutionary arms race fought at the level of gene regulation. Nematodes exploit conserved host hubs, from the COP9 signalosome to JAZ proteins and translation initiation factors, that other pathogens also target, suggesting shared vulnerabilities that could yield broadly durable resistance. Plants, for their part, retain the capacity to resist when their immune signaling outpaces the parasite’s reprogramming, as resistant interactions shift the sex ratio of developing nematodes toward males and curtail reproduction. Decoding the precise choreography of effectors, hormones, transcription factors, and epigenetic marks, the authors conclude, is not merely an academic exercise but a prerequisite for engineering crops that refuse to build the parasite’s dining room, a goal with enormous implications for global food security as biotic pressures on agriculture intensify.

Subject of Research: Molecular mechanisms of feeding site formation and transcriptional reprogramming in plant-parasitic nematode interactions

Article Title: Cellular plasticity and transcriptional reprogramming in plant-nematode interactions: insights into feeding site formation and plant defense

Article References: Yusuf, A. G., & Bello, T. T. (2025). Cellular plasticity and transcriptional reprogramming in plant-nematode interactions: insights into feeding site formation and plant defense. Crop Health, 3(1), Article 16. https://doi.org/10.1007/s44297-025-00056-1

Image Credits: AI Generated

DOI: 10.1007/s44297-025-00056-1

Keywords: plant-parasitic nematodes, root-knot nematode, cyst nematode, giant cells, syncytium, transcription factors, effector proteins, auxin signaling, cytokinin, plant immunity, CRISPR, RNA interference

The study, published in Plant Cell Reports, took a comparative approach. The researchers set up a cotyledonary node-based system for inducing adventitious shoots, the standard route for Agrobacterium-mediated soybean transformation, and ran it side by side on two dramatically different varieties. Dongnong 50, a Chinese cultivar, regenerates shoots readily and is a favorite of transformation labs. Gongqiudou 5, a Sichuan landrace, has a notoriously low regenerative capacity. By sequencing the RNA of both varieties at multiple time points after shoot induction, the team could watch the molecular choreography of regeneration unfold in a high-regenerating and a low-regenerating background, and pinpoint where the two performances diverged.

The transcriptome comparison delivered a clear first message: the hormone machinery behaves differently in the two cultivars. Pathways related to hormone signaling were significantly enriched among the differentially expressed genes, and the genes that respond to auxin and cytokinin, the two hormones that jointly orchestrate de novo shoot organogenesis, showed distinct temporal dynamics between Dongnong 50 and Gongqiudou 5. In other words, the two varieties are not merely differing in how much hormone they perceive, but in the timing and coordination of their transcriptional responses as wounded tissue attempts to reprogram itself into meristem-producing cells.

That timing matters because adventitious shoot formation is a race against fate. When a cotyledonary node explant is placed on induction medium, cells near the wound must abandon their mature identity and rebuild the gene-expression program of a shoot apical meristem, the self-renewing stem cell pool from which all aerial organs arise. Decades of work in Arabidopsis and other species have established that auxin and cytokinin cross-talk lies at the heart of this reprogramming, with auxin typically driving initial cell fate transitions and cytokinin promoting meristem identity and shoot outgrowth. The soybean data show that the regenerable cultivar executes this hormonal script more effectively, while the recalcitrant landrace appears to fall out of step.

To move from a list of differentially expressed genes to an actual causal regulator, the team layered on two computational filters. First, they performed co-expression network analysis, grouping genes whose expression patterns rise and fall together across the regeneration time course, on the logic that a master regulator should sit at the hub of a module containing the downstream machinery it controls. Second, they scanned the promoters of genes in those modules for enriched DNA sequence motifs, the binding sites through which transcription factors recognize their targets. The intersection of both analyses converged on one candidate: GmRAMOSA1, abbreviated GmRA1, a soybean relative of a gene first made famous in maize.

The RAMOSA name carries history. In maize, RAMOSA1 was identified as a key controller of axillary meristem fate during inflorescence development, shaping the branching architecture of the tassel and ear. The gene encodes a transcription factor whose loss in maize mutants produces highly branched, spike-like inflorescences. Intriguingly, related work has shown that overexpressing the maize RAMOSA1 gene in Arabidopsis increases organ size through cell expansion, hinting that the protein’s influence on growth and development extends beyond its original floral context. The new soybean study now assigns the gene a role in a completely different developmental arena: the in vitro rebirth of shoots from adult tissue.

The functional test was direct. The researchers overexpressed GmRA1 in the Gongqiudou 5 background, effectively installing the gene into the very cultivar that regenerates poorly. The result was a significant increase in adventitious shoot regeneration, demonstrating that the candidate is not merely correlated with regenerative ability but capable of improving it. Molecular profiling of the engineered plants revealed elevated expression of several meristem-identity genes and hormone-responsive genes, consistent with GmRA1 acting upstream of the very programs that the transcriptome comparison had shown to be sluggish in the recalcitrant landrace.

Why does this matter beyond the petri dish? Soybean transformation efficiency is the bottleneck that slows every downstream application, from herbicide-tolerant lines to genome-edited varieties with improved oil composition, disease resistance, or climate resilience. Because regeneration is genotype-dependent, most commercial cultivars remain effectively off-limits to routine genetic manipulation, forcing researchers to transform a handful of amenable varieties and then breed the desired trait into elite backgrounds, a process that can add years to a product pipeline. A regulator like GmRA1, if deployed broadly, could raise the regenerative ceiling across diverse genetic backgrounds and make transformation faster, cheaper, and more widely applicable.

The finding also fits into a rapidly expanding toolkit of regeneration-boosting genes. Around the world, laboratories have shown that overexpressing developmental regulators such as WUSCHEL, BABY BOOM, GRF-GIF fusions, and TaLAX1 can dramatically enhance regeneration and transformation in crops ranging from wheat to apple to ornamentals. Each new addition to this list expands the range of species and genotypes that can be engineered. GmRA1 is notable because it emerged not from a model organism but from a direct comparison of two soybean varieties that differ in the trait of interest, meaning it was discovered precisely where soybean breeders and biotechnologists need it.

The Sichuan team, led by corresponding authors Xin Sun and Junbo Du, with Yuhan Liu and Xinxin Zhang as co-first authors, frames the work as a new window into the molecular mechanism of soybean shoot organogenesis. The study was supported by the National Natural Science Foundation of China and Sichuan provincial science programs, and the authors report no conflicts of interest. Much remains to be tested, including how GmRA1 interacts with the auxin and cytokinin signaling components identified in the transcriptome comparison, and whether boosting its activity carries any trade-offs in plant development. But the central result stands: a gene that once helped shape maize ears now appears to hold sway over whether a soybean cell will consent to become a whole new plant. For a crop whose genetic improvement has been gated by regeneration for decades, that is a switch worth flipping.

Subject of Research: Molecular regulation of adventitious shoot regeneration in soybean

Article Title: Comparative transcriptome profiling and functional analysis of GmRAMOSA1 as a key regulator of adventitious shoot regeneration in soybean

Article References: Liu, Y., Zhang, X., Jiang, H., Mu, D., Qin, Q., Wu, W., Zhou, Y., Zhang, Y., Gu, J., Yang, H., He, J., Huang, Y., Sun, X., & Du, J. (2026). Comparative transcriptome profiling and functional analysis of GmRAMOSA1 as a key regulator of adventitious shoot regeneration in soybean. Plant Cell Reports, 45(10), Article 308. https://doi.org/10.1007/s00299-026-03996-2

Image Credits: AI Generated

DOI: 10.1007/s00299-026-03996-2

Keywords: soybean, GmRAMOSA1, adventitious shoot regeneration, transcriptome, auxin, cytokinin, genetic transformation, plant biotechnology, meristem, cotyledonary node, Plant Cell Reports, gene regulation

The classic experimental system for studying plant regeneration is the two-step tissue culture protocol. Explants, small pieces of plant tissue, are first placed on a callus induction medium containing a balanced ratio of the plant hormones auxin and cytokinin. Under these conditions, a subset of cells re-enters the cell cycle and proliferates into callus, a disorganized mass of cells that resembles lateral root primordia more than any mature tissue. When the callus is then transferred to a shoot induction medium rich in cytokinin, some cells adopt shoot identity and form a shoot apical meristem, the self-renewing stem cell hub that generates leaves, stems, and eventually flowers. Understanding the molecular switches that govern each of these transitions has become one of the central questions in plant developmental biology.

At the heart of the process lies hormonal control. Auxin, arguably the most influential player, drives dedifferentiation and callus formation, and its signaling operates through transport inhibitor response 1 receptors and auxin response factors that directly regulate reprogramming genes. Work in Arabidopsis thaliana has shown that auxin upregulates LEAFY COTYLEDON 1 and 2, transcription factors central to somatic embryogenesis. Studies in rice further revealed that local auxin gradients determine whether regenerating tissues form roots or shoots: high auxin with low cytokinin favors roots, while the opposite combination promotes shoots. PIN-FORMED transport proteins channel auxin directionally to specific sites, initiating de novo root organogenesis with remarkable spatial precision.

Cytokinin acts as auxin’s counterweight. It sustains cell division and, at high concentrations, promotes shoot primordia formation, while lower levels favor roots or somatic embryos. Cytokinin signaling flows through the Arabidopsis response regulator family, and type-B regulators such as ARR1, ARR2, ARR10, and ARR12 bind directly to the promoter of WUSCHEL, the master gene that maintains stem cell activity in the shoot apical meristem. Cytokinin also suppresses auxin accumulation through the YUCCA biosynthetic pathway, and remarkably, it reaches into the epigenetic machinery by modulating histone acetyltransferases, thereby making meristem maintenance genes more accessible for transcription. Mutations in type-B response regulators impair shoot regeneration, whereas overexpressing ARR12 enhances it, and WUSCHEL overexpression can rescue defective regeneration in double mutants, underscoring the centrality of this regulatory module.

Other hormones fine-tune the process. Gibberellins do not initiate reprogramming but sustain proliferation and maturation once cells have been redirected, promoting the elongation of somatic embryos into functional plantlets. Brassinosteroids, acting through the BRI1 receptor, synergize with auxin and cytokinin to boost cell division in callus and support organ formation. Abscisic acid, the stress hormone, plays the antagonist: elevated levels suppress cell division and organogenesis, inducing a dormancy-like state that prevents cells from reverting to totipotency under unfavorable conditions. ABA and cytokinin act antagonistically in shoot regeneration, illustrating how plants calibrate their regenerative responses against environmental risk.

Beneath the hormonal layer sits an elaborate gene regulatory network. Callus formation begins with the division of xylem pole pericycle cells, a process sharing molecular logic with lateral root initiation. The ALF4 protein initiates pericycle division, and root meristem genes including WOX5, WOX11, SCARECROW, PLETHORA 1 and 2, and SHORT ROOT become strongly upregulated. Mutant analyses confirm their importance: plt3plt5plt7 mutants lose shoot progenitor regeneration, and lbd16 mutants show reduced expression of WOX5 and PLETHORA genes with diminished shoot regeneration. On shoot induction medium, CUC1 and CUC2 transcription factors mark pre-meristematic zones, recruit PIN1 polarization, and activate SHOOT MERISTEMLESS to define future shoot progenitors, while ESR1 and ESR2 act upstream to promote the process. A transient root stem cell niche, marked by WOX5 expression, appears to be a prerequisite for the subsequent switch to shoot identity.

Small RNAs add another layer of temporal and spatial control. The miR156-SPL module explains why regeneration efficiency declines with plant age: juvenile plants with high miR156 repress SPL transcripts, keeping cytokinin responses active, whereas older plants accumulate SPL proteins that suppress type-B response regulators and reduce regeneration. miR165/166 promotes shoot formation, and the ARGONAUTE10 protein sequesters these microRNAs, with ago10 mutants showing elevated miR165/166 and enhanced regeneration. Meanwhile, a miR160-ARF10-ARR15 cascade fine-tunes the early balance between auxin and cytokinin signaling during callus formation, demonstrating how microRNA circuits integrate hormonal cues across developmental stages.

Perhaps the most striking insight from the review is that reprogramming is governed less by genetic change than by epigenetic rewiring. Global DNA hypomethylation is a hallmark of callus formation across species. In Arabidopsis, MET1 maintains CG methylation, and its loss increases WUSCHEL transcription and accelerates shoot formation; met1 mutants produce more shoots. Yet local hypermethylation also matters, silencing organ identity genes such as GSTU10, MAPK12, and BXL1 to help establish an undifferentiated cell mass. Histone marks are equally dynamic: H3K9ac and global H3 acetylation rise during callus formation, activating sugar metabolism, peptide signaling, and hormone transport genes while repressing photosynthesis programs. The demethylase JMJ30 removes repressive H3K9me3 marks from LBD16 and LBD29 promoters to enable callus formation, while ATX4 deposits activating H3K4me3 at shoot identity genes. Loss of the deacetylase HDA19 suppresses shoot regeneration, showing that both writing and erasing these marks is essential.

Proteomic studies, though still limited in number, reveal consistent patterns. Embryogenic cells accumulate heat-shock proteins as molecular chaperones, elevated glutathione-S-transferases that detoxify auxin, and cytoskeletal components such as tubulin and actin that establish cell polarity during division. Carbohydrate metabolism enzymes, photosynthetic proteins that appear as embryos mature, and nuclear import factors like importin all shift in abundance, reflecting the massive metabolic and architectural reorganization that accompanies the acquisition of pluripotency. Reactive oxygen species homeostasis intersects with auxin signaling during dedifferentiation, linking stress physiology directly to developmental potential.

New technologies are transforming the field’s resolution. Single-cell RNA sequencing has mapped the cellular composition of Arabidopsis and rice roots, revealed hormone signaling variation across cell clusters, and, when combined with ATAC-seq, identified WUSCHEL and DORNROESCHEN as crucial factors for regenerating mesophyll cells. CRISPR-based activation has been used to enhance somatic embryogenesis in tomato by targeting the SlWRKY29 gene, and CRISPR-dCas9 systems now allow precise transcriptional tuning of master regulators. Even artificial intelligence has entered the tissue culture lab: machine learning models, including neural networks and gradient boosting algorithms, have successfully predicted optimal media compositions for callus induction in carrot, micropropagation of lavender, and callogenesis in saffron, cutting both cost and experimental time. Together, these tools point toward a future in which regeneration efficiency can be engineered rather than stumbled upon, with implications for crop improvement, the propagation of recalcitrant and endangered species, and a deeper understanding of how any cell, given the right molecular instructions, can be persuaded to start over.

Subject of Research: Molecular mechanisms of cell fate reprogramming during de novo organogenesis in plants

Article Title: Understanding the molecular landscape of de novo organogenesis: insights into cell fate reprogramming

Article References: Nath, J., Kumari, A., Joshi, S., Gusain, S., Kumari, K., Yadav, S. K., & Joshi, R. (2025). Understanding the molecular landscape of de novo organogenesis: insights into cell fate reprogramming. Discover Biotechnology, 2(1), Article 27. https://doi.org/10.1007/s44340-025-00035-w

Image Credits: AI Generated

DOI: 10.1007/s44340-025-00035-w

Keywords: de novo organogenesis, cell fate reprogramming, auxin, cytokinin, WUSCHEL, epigenetics, DNA methylation, histone modification, callus, single-cell RNA sequencing, CRISPR, plant regeneration