Provenance 4 had the lowest mean branch inclination angle, while provenance 2 had the highest proportion of narrow-crowned individuals and the highest measured zeatin levels. Auxin, or indole-3-acetic acid, was lowest in provenance 14. Across the 14 provenances, branch inclination angle was significantly negatively correlated with both zeatin and indole-3-acetic acid. Path analysis indicated a strong negative direct effect of indole-3-acetic acid on branch inclination angle. These findings describe statistical and model-based relationships among the measured variables; the abstract does not report experimental manipulation or direct functional testing of the proposed mechanism.

The transcriptome analysis identified 2,272 differentially expressed genes, including 27 associated with phytohormone signaling pathways. Six members of the SAUR family were up-regulated and three were down-regulated in the narrow-crowned provenance, with distinct expression patterns suggesting that they may participate in auxin-signaling output during branch inclination angle development. Cytokinin regulators A-ARR and B-ARR showed opposite expression patterns. The gibberellin receptor GID1 was down-regulated and the growth-repressor DELLA was up-regulated, which the authors interpreted as consistent with reduced promotion of cell division and elongation.

Additional expression differences were reported in salicylic acid, jasmonic acid, abscisic acid and ethylene signaling. Genes in salicylic acid and jasmonic acid signaling were suppressed, the abscisic acid regulator PP2C decreased and the ethylene-associated component EIN2 increased. The authors interpreted this pattern as evidence of reprogramming in defense-related phytohormone signaling. They concluded that auxin and downstream SAUR genes may be important in regulating branch inclination angle and that provenances 3 and 4 warrant attention as narrow-crowned sources. However, the supplied evidence is an abstract from an early, accepted manuscript subject to further edits; it does not provide detailed sampling methods, effect sizes, uncertainty estimates or functional validation, so the specific molecular mechanisms and breeding implications remain bounded by the reported comparative analysis.

Subject of Research: Provenance-associated phytohormone and gene-expression patterns underlying branch inclination angle variation in Chamaecyparis hodginsii

Article Title: Phytohormone and transcriptome analyses reveal the mechanisms underlying branch inclination angle formation in narrow-crowned Chamaecyparis hodginsii

Article References: Cai, X., Chen, Z., Bai, J., Xiao, J., Liu, J., Lin, Y., Lin, Y., Lu, B., Gao, T., Chen, L., He, T., Chen, L., Rong, J., & Zheng, Y. (2026). Phytohormone and transcriptome analyses reveal the mechanisms underlying branch inclination angle formation in narrow-crowned Chamaecyparis hodginsii. BMC Plant Biology. https://doi.org/10.1186/s12870-026-10049-z

Image Credits: AI Generated

DOI: 10.1186/s12870-026-10049-z

Keywords: Chamaecyparis hodginsii, branch inclination angle, narrow-crowned provenances, auxin, zeatin, SAUR genes, cytokinin signaling, transcriptome analysis, phytohormones, forest tree breeding, Phytohormone, transcriptome

The smoke tree is a striking shrub best known for the wispy, smoke-like plumes that give it its common name, but its heartwood has long attracted attention from natural products chemists. Heartwood extracts of C. coggygria are rich in flavonoids, a sprawling family of plant secondary metabolites that includes many compounds with documented anticancer activity in laboratory settings. Earlier work had established that butin, butein, and sulfuretin exhibit cytotoxic effects against leukemia cells, yet the molecular mechanisms underlying these effects in K562 cells—a widely used model of chronic myeloid leukemia—remained poorly defined. The new study set out to close that gap by treating the cells with the purified compounds as well as with crude heartwood extracts prepared with ethanol, water, and a methylene chloride/methanol mixture.

The experimental design combined classical pharmacology with modern genomics. Flow cytometry was used to determine how the treatments altered cell cycle distribution and whether they triggered the activation of apoptosis, the programmed cell death pathway that many anticancer therapies seek to engage. To pin down the mode of cell death, the researchers employed caspase inhibition, a technique that reveals whether cell death depends on the caspase enzymes that execute apoptosis. The centerpiece of the study, however, was the transcriptomics: three independent mRNA sequencing experiments were performed on treated K562 cells, and the resulting data were subjected to differential gene expression analysis followed by pathway-level analyses using the Reactome and KEGG databases through gene set enrichment analysis, or GSEA. Network and pathway-cluster analyses then tied the individual enriched pathways together into coherent biological stories.

The headline finding is that all three flavonoids push leukemia cells in a broadly similar direction—toward growth suppression, a metabolic downshift, and the activation of adaptive stress-response networks—but each compound leaves its own distinctive fingerprint on the transcriptome. Butein emerged as the most transcriptionally aggressive of the three, inducing 809 differentially expressed genes. Butin followed with 439 differentially expressed genes, and sulfuretin produced 299. Despite these differences in breadth, the team identified 134 differentially expressed genes shared across all three treatments, suggesting a common core response to this family of flavonoids that may underlie their shared antileukemic activity.

Butin’s transcriptomic signature tells a story of systematic shutdown. Treatment with this compound produced a transcriptional shift marked by the suppression of RNA processing, mRNA splicing, translation initiation, and mitochondrial bioenergetics. In practical terms, the compound appears to choke off the leukemia cell’s ability to read out its genetic information, mature its messenger RNAs, and manufacture new proteins, while simultaneously starving the cell’s power plants. The enrichment analysis pointed specifically to downregulation of oxidative phosphorylation, the OXPHOS system that generates most of a cell’s ATP, and of the tricarboxylic acid cycle, or TCA cycle, which feeds that system. For rapidly dividing cancer cells, which depend heavily on coordinated protein synthesis and mitochondrial metabolism, this dual hit represents a serious metabolic and biosynthetic crisis.

Butein, the most potent transcriptional perturber, induced a strikingly coordinated downregulation of many of the same programs. Mitochondrial respiration, RNA maturation, mRNA maturation, and mRNA transport were all suppressed after butein treatment, indicating that the compound disrupts both the energy supply and the information-processing pipeline of the leukemic cell. The overlap between butin and butein is notable from a chemical biology standpoint: both compounds share a core flavonoid scaffold, and their convergent effects on mitochondrial and RNA-related pathways suggest that these processes may be particularly vulnerable targets for this class of molecules. At the same time, the fact that butein altered nearly twice as many genes as butin hints at additional, compound-specific activities that remain to be fully characterized.

Sulfuretin stood apart. Instead of the broad biosynthetic and metabolic shutdown seen with its two chemical cousins, sulfuretin displayed a distinct pattern characterized by positive enrichment of stress, inflammatory, immune, and proteasome-related pathways. In other words, treated cells mounted what looks like an adaptive stress response, ramping up programs associated with inflammation and protein quality control. Alongside this activation, the analysis revealed negative enrichment of RB1/E2F-associated G1/S transition programs—a reference to the molecular circuitry that governs the transition from the G1 phase of the cell cycle into DNA synthesis. Suppressing this program suggests that sulfuretin may hold leukemia cells at the G1 checkpoint, preventing them from committing to another round of cell division.

These findings matter because they move the field beyond the simple observation that a plant compound kills cancer cells in a dish. By resolving the transcriptomic architecture of the response, the study offers mechanistic hypotheses that can be tested directly: whether the compounds induce reactive oxygen species through mitochondrial dysfunction, whether the proteasome activation seen with sulfuretin reflects a genuine unfolded protein burden, and whether the shared 134-gene core response contains biomarkers that predict sensitivity to flavonoid treatment. The authors also emphasize that the framework they have built is not limited to leukemia. Because the transcriptomic signatures point to fundamental processes—protein synthesis, mitochondrial respiration, cell cycle control—their approach can be translated to other types of malignancy, where the same compounds might exploit different vulnerabilities depending on the tissue of origin.

The study also illustrates the power of pathway-level analysis over simple gene lists. Differential expression analysis alone can identify thousands of changed transcripts, but GSEA against curated databases such as Reactome and KEGG, combined with network and pathway-cluster analyses, revealed that the changed genes were not scattered at random. Instead, they converged on coherent biological modules—RNA processing, translation initiation, OXPHOS, TCA cycle, G1/S transition, proteasome function—that together explain how a flavonoid treatment can translate into cytotoxicity. The team’s careful handling of technical variation, documented in supplementary analyses showing sample clustering before and after batch correction, adds confidence that the observed signatures reflect biology rather than experimental noise.

For now, the work remains at the level of cell culture, and the usual caveats apply: concentrations that are cytotoxic in a dish do not automatically translate into safe and effective drugs, and the pharmacokinetics of flavonoids in the human body are notoriously complex. But the study delivers something that earlier cytotoxicity screens could not—a transcriptomic framework for further investigation of the antileukemic properties of butin, butein, and sulfuretin. As interest in natural products as sources of anticancer lead compounds continues to grow, the smoke tree’s heartwood chemistry has just become considerably more interesting, and the road from Balkan shrub to molecular medicine has gained a well-marked first milestone.

Subject of Research: Transcriptomic effects of Cotinus coggygria flavonoids on K562 myeloid leukemia cells

Article Title: Transcriptome analysis of K562 myeloid leukemia cells treated with butin, butein, and sulfuretin from the heartwood of Cotinus coggygria Scop.

Article References: Pašić, I., Sami, A., Novaković, M., Tešević, V., Petrović, N., Vlatković, T., Stanojković, T., Žegarac, M., & Matić, I. Z. (2026). Transcriptome analysis of K562 myeloid leukemia cells treated with butin, butein, and sulfuretin from the heartwood of Cotinus coggygria Scop.. BMC Complementary Medicine and Therapies. https://doi.org/10.1186/s12906-026-05570-5

Image Credits: AI Generated

DOI: 10.1186/s12906-026-05570-5

Keywords: Cotinus coggygria, flavonoids, butin, butein, sulfuretin, K562 leukemia cells, transcriptome analysis, RNA sequencing, gene set enrichment analysis, apoptosis, mitochondrial respiration, natural products

The biology of birch reproduction makes this achievement particularly striking. Unlike annual plants that complete flowering within weeks, the male inflorescence of B. platyphylla develops over nearly an entire year. The catkins initiate in spring, then overwinter in a dormant state as uninucleate microspores, suspended in time until they resume development and release pollen the following season. Any gene that governs this long, cold-interrupted program must therefore act with precise timing, and understanding where that timing goes wrong is essential if breeders want to deliberately shut down pollen production without harming the tree.

The research began with an unusual natural specimen. A single spontaneous mutant individual of B. platyphylla was found bearing two distinct types of abnormal male inflorescences, designated WLM and MM, alongside comparison with wild-type plants. At three key developmental stages, the microspore mother cell stage, the tetrad and microspore stage, and the mature pollen stage just before pollination, the team carried out detailed phenotypic observations paired with transcriptome sequencing. Both mutant inflorescence types showed impaired pollen grain maturation and defective anther dehiscence at stage 6, confirming that the mutation disrupts the male reproductive program at multiple points.

As floral development progressed, the scale of the molecular disruption became increasingly dramatic. The number of differentially expressed genes between the mutant inflorescences and wild type rose markedly from stage to stage, indicating that the underlying defect compounds over time rather than resolving. Pathway enrichment analysis of these differentially expressed genes pointed to several biochemical routes as potentially critical for birch male flower development, most notably phenylpropanoid biosynthesis and ABC transporter activity. Both categories make biological sense: phenylpropanoid metabolism supplies building blocks for sporopollenin, the extraordinarily tough polymer that forms the pollen exine, while ABC transporters ferry lipidic precursors from the tapetum to the developing microspores.

Within the gene ontology analysis, the researchers identified 31 candidate genes linked to pollen exine formation, the sporopollenin biosynthetic process, and anther development. Among them were BpSPL8, encoding a SQUAMOSA PROMOTER BINDING PROTEIN-LIKE transcription factor; BpAPY7, an apyrase previously implicated in exine patterning and anther dehiscence in other species; and BpCYP703A2, a cytochrome P450 enzyme known from land plants as a catalyst for in-chain hydroxylation of lauric acid, providing essential building blocks for sporopollenin synthesis. The presence of these familiar players confirmed that birch uses a conserved genetic toolkit for pollen wall construction, while the mutant context revealed how that toolkit is coordinated.

The decisive insight came from phylogenetic and co-expression analyses, which converged on BpSPL2 as a core regulator sitting at the top of the network. SPL genes belong to a family of SBP-box transcription factors with well-documented roles in flowering time, leaf morphology, and fertility across the plant kingdom, and previous work in Arabidopsis had shown that both miR156-targeted and non-targeted SPL genes act together to secure male fertility. To test whether BpSPL2 was genuinely causal rather than merely correlated with sterility, the team manipulated its expression in birch and observed the consequences directly.

The results were unambiguous and, in one direction, dramatic. When BpSPL2 was overexpressed, microsporogenesis was arrested at the microsporocyte stage itself, before meiosis could proceed to tetrad formation. The arrested cells subsequently degraded during the overwintering period, ultimately yielding no microspores and no pollen whatsoever. In other words, elevating this single transcription factor completely abolishes pollen production by stopping development at its earliest cellular step. Conversely, suppressing BpSPL2 produced the opposite phenotype: microsporogenesis was promoted, and the resulting inflorescences and anthers became enlarged. The gene thus behaves as a temporal switch whose dosage determines whether, when, and how far the pollen developmental program advances.

These findings establish BpSPL2 as a key temporal regulator of microsporogenesis in B. platyphylla and provide a mechanistic account of two distinct abnormal male flower phenotypes arising on a single spontaneous mutant. The study is also notable for its systematic design: by sampling the same mutant individual at three developmental stages across a nearly year-long cycle and integrating phenotypic cytology with transcriptome-wide expression profiling, the authors built a stage-resolved picture of how male sterility unfolds in a long-lived tree, a scale of analysis rarely achieved in forest reproductive genetics.

The practical implications extend well beyond basic biology. Birch pollen is a significant allergen, and sensitization to birch is strongly correlated with pollen-food allergy syndrome in northern China, where reactions to soy and apple frequently accompany birch pollen allergy. A pollen-free birch variety would remove the allergen at its source rather than treating symptoms, an attractive proposition for urban landscaping and allergy-prone regions. The new work provides both a theoretical foundation and concrete genetic resources for such breeding: the 31 candidate genes, the pathway maps, and above all the BpSPL2 switch itself give breeders molecular targets for generating sterile lines, whether through conventional marker-assisted selection, transgenic modulation, or genome editing approaches that have already proven effective for fertility genes in crops.

There are broader lessons here for tree biotechnology as well. Pollen-mediated gene flow has long been a concern for genetically modified forest plantations, and sterile varieties would simultaneously address allergenicity and containment. The birch study demonstrates that in long-cycle woody species, where traditional crossing and transformation are slow, a spontaneous mutant coupled with modern transcriptomics can shortcut decades of genetic analysis. By pinpointing one master regulator in a tree whose catkins spend a winter as dormant microspores, the researchers have shown that even the most patient developmental programs in plants can be understood, and potentially rewritten, at the level of a single gene.

Subject of Research: Molecular regulation of male sterility and microsporogenesis in Betula platyphylla

Article Title: Transcriptome analysis of a spontaneous male-sterile mutant in Betula platyphylla and functional characterization of the key gene BpSPL2 in regulating inflorescence development

Article References: Zeng, M., Song, Z., Feng, S., Huang, P., Hu, X., Liu, Y., Wang, Y., Zhang, H., & Liu, X. (2026). Transcriptome analysis of a spontaneous male-sterile mutant in Betula platyphylla and functional characterization of the key gene BpSPL2 in regulating inflorescence development. Plant Cell Reports, 45(10), Article 294. https://doi.org/10.1007/s00299-026-03970-y

Image Credits: AI Generated

DOI: 10.1007/s00299-026-03970-y

Keywords: Betula platyphylla, male sterility, BpSPL2, microsporogenesis, pollen development, transcriptome analysis, SPL transcription factors, sporopollenin, anther development, forest tree breeding, birch pollen allergy, inflorescence development

BOSCC is the primary epithelial neoplasm of the eye in cattle, arising in the conjunctiva, corneoscleral junction, nictitating membrane, cornea, and eyelids. It can develop from pre-existing papillomas or emerge independently as an invasive tumor capable of spreading to the ocular bone and adjacent structures through lymph nodes. Multiple environmental and genetic factors drive its development, including ultraviolet radiation, viral infections, diet, age, and above all, the lack of ocular pigmentation that characterizes Hereford cattle. Because melanin provides photoprotection against ultraviolet damage, animals with depigmented ocular areas are far more vulnerable, and approximately 30 percent of cases carry hereditary causes.

The research team, led by Nariné Balemian of the Universidad de la República in Uruguay, collected tumor samples from five adult purebred Hereford cattle during field surgeries conducted by qualified veterinarians, following animal welfare protocols. Control corneal tissues were obtained from three healthy animals of the same breed and similar age with non-pigmented ocular regions. Each sample was divided for histological analysis and whole transcriptome sequencing. The tissues were fixed, dehydrated through an ascending ethanol series, embedded in wax, and stained with Hematoxylin-Eosin before digital image analysis, while RNA was extracted and sequenced using DNBseq technology generating at least 45 million paired-end reads per sample.

Histopathological examination confirmed classic BOSCC features across all cases. The corneal epithelium is normally stratified but non-keratinizing, so the presence of extensive keratin pearls reflects squamous differentiation of tumor cells rather than native corneal biology. Eighty percent of tumors showed complete depigmentation of the upper eyelid, and the nictitating membrane was affected in 80 percent of cases. All samples exhibited lymphocytic infiltration, increased mitotic activity, and elevated vascularization, and 40 percent of samples also contained melanocytes interspersed within the tumoral process, a feature compatible with pigmented squamous cell carcinoma variants reported in veterinary and human pathology.

Whole transcriptome sequencing identified 836 genes underexpressed and 845 genes overexpressed in tumor tissue compared with healthy controls. Among the most significantly upregulated genes were TRPV3, KRT6A, KLK6, MMP13, PROKR2, IL31RA, DHRS9, and MMP9, with log2 fold-change values between 6 and 11. KRT6A is a stress-responsive cytokeratin essential for squamous differentiation and re-epithelialization, while KLK6 is a serine protease implicated in epithelial cell invasion. TRPV3, a calcium channel characteristic of stratified squamous epithelia, likely marks adoption of a keratinizing program by ocular surface tumor cells. MMP9 and MMP13 are classic mediators of basement membrane and stromal degradation that facilitate invasion and angiogenesis.

The downregulated set included GPHA2, TNN, EMILIN3, BGLAP, TGFB1, MATN4, CHAD, and CLEC3A, with log2 fold-change values between −12 and −6. Several of these genes maintain limbal stem cells, cell adhesion, and tumor suppression. The downregulation of GPHA2, a limbal stem-cell marker, is consistent with disturbance of ocular surface homeostasis, while reduced expression of adhesion and matrix regulators such as CHAD, EMILIN3, MATN4, TNN, and CLEC3A fits with altered stromal architecture during invasion. TGFB1, which can act as a tumor suppressor early in cancer but promote tumor growth at advanced stages, showed decreased expression in these samples.

Gene Ontology and KEGG pathway analyses revealed coordinated disruptions across immune response, transcriptional misregulation in cancer, and viral protein interactions with cytokines and cytokine receptors. Of the 72 altered genes in the cytokine–cytokine receptor interaction pathway, 67 were upregulated, and all 31 genes in the viral protein interaction pathway were upregulated, suggesting a strong cytokine-mediated inflammatory milieu within the tumor microenvironment. CXCL8, also known as IL-8, was upregulated, consistent with protumorigenic roles in invasion, angiogenesis, and matrix metalloproteinase activation, and with ultraviolet-induced IL-8 production in corneal epithelium. IL31RA was also elevated, aligning with reports that IL-31 signaling can promote tumor progression and metastasis.

The authors caution that the viral protein interaction signal likely reflects heightened immune activation rather than direct proof of viral causation, though papillomaviruses are known to act as cofactors with ultraviolet radiation in non-melanoma skin cancer, a possibility deserving further research. The study also carries limitations: the modest cohort size, anatomical heterogeneity among tumors, and bulk RNA sequencing without single-cell resolution may blur epithelial, stromal, and immune contributions. Future work should validate key proteins by immunohistochemistry, localize expression in situ, incorporate single-cell approaches, screen for viral sequences, and compare breeds with different pigmentation phenotypes.

Nevertheless, this first global expression profile of BOSCC provides a mechanistic framework uniting tumor-associated inflammation, epithelial keratinization, extracellular matrix remodeling, and disruption of limbal homeostasis. Because the samples were collected during routine field work under extensive management conditions, they reflect the pathological cases veterinarians face daily. The researchers hope the gene panel identified here will serve as a foundation for future genomic studies and, in the long term, enable molecular tests for selecting non-susceptible breeding animals, potentially reducing the burden of this cancer in Hereford cattle through informed selective breeding programs.

Subject of Research: Transcriptome analysis of bovine ocular squamous cell carcinoma in Hereford cattle

Article Title: Transcriptome analysis of bovine ocular squamous cell carcinoma (BOSCC) in Hereford cattle

Article References: Balemian, N., Pedrana, G., Fernández-Calero, T., Irabuena, O., & Armstrong, E. (2026). Transcriptome analysis of bovine ocular squamous cell carcinoma (BOSCC) in Hereford cattle. Veterinary Oncology, 3(1), Article 8. https://doi.org/10.1186/s44356-026-00058-3

Image Credits: AI Generated

DOI: 10.1186/s44356-026-00058-3

Keywords: bovine ocular squamous cell carcinoma, BOSCC, Hereford cattle, transcriptome analysis, RNA-seq, gene expression, cancer biology, veterinary oncology, ocular tumor, keratinization, tumor microenvironment, selective breeding

Selenium occupies a curious position in plant biology. It is not considered an essential element for higher plants, yet it functions as a cofactor for a suite of antioxidant enzymes, including the glutathione peroxidases, and it participates in secondary metabolism, stress responses, and the ripening process. For humans, the picture is clearer: selenium is an essential micronutrient, and deficiency affects an estimated one billion people worldwide, with consequences ranging from compromised immune function to increased oxidative stress. Because dietary selenium intake depends heavily on the selenium content of soils where crops are grown, agronomic biofortification—enriching food crops with selenium through fertilization—has emerged as a major strategy in global nutrition efforts. Foliar spraying, in which a selenium solution is applied directly to leaves and developing fruit, is particularly attractive because it bypasses the complex soil chemistry that often locks selenium into unavailable forms and allows precise control over dose and timing.

The Chinese dwarf cherry, known in China as Oula Li, is a small drupe native to northern China that has attracted growing scientific and commercial attention. Despite its modest size, the fruit accumulates remarkable levels of phenolic compounds, flavonoids, anthocyanins, and vitamin C, and previous studies have documented substantial genotypic diversity in its antioxidant capacity. It is also valued for its calcium content and has been the subject of metabolomic investigations into its organic acid composition. Yet until now, no comprehensive study had examined how exogenous selenium application affects the fruit’s quality, selenium accumulation, or the underlying gene expression programs that govern its flavonoid biosynthesis.

To fill this gap, the research team sprayed ‘Jinou-2’ Chinese dwarf cherry trees with sodium selenite solutions ranging from 0 to 150 milligrams per liter, applying the treatments at two critical developmental windows: the young fruit stage and the fruit expansion stage. These stages were chosen because they represent periods of intense cell division and resource allocation, when the fruit’s metabolic machinery is most responsive to external inputs. After treatment, the researchers measured a battery of fruit quality parameters, including fruit size, peel coloration, soluble solids, organic acid and ascorbic acid content, selenium concentration and speciation, flavonoid and anthocyanin levels, and overall antioxidant activity. They then performed transcriptome sequencing on treated and untreated fruit to identify the genes and pathways responding to selenium.

The results were strikingly dose-dependent. At 120 milligrams per liter, sodium selenite produced the most remarkable improvements across nearly every quality metric. Fruits were larger, their peels displayed deeper redness—an indicator of anthocyanin accumulation—and their flavor profile improved. Critically, the treatment shifted the speciation of selenium within the fruit: the proportion of organic selenium rose while inorganic selenium declined. This shift matters enormously from a nutritional and safety standpoint. Organic selenium compounds, such as selenomethionine incorporated into proteins, are generally more bioavailable and less toxic than inorganic selenite or selenate, so a fruit that converts absorbed inorganic selenium into organic forms delivers a safer and more effective nutritional payload.

Alongside the selenium transformation, the treated fruits showed significantly enhanced antioxidant activity, accompanied by marked increases in ascorbic acid, total flavonoids, and anthocyanins. These compounds form the chemical backbone of the fruit’s health-promoting reputation, and their coordinated elevation suggests that selenium acts not merely as a passive accumulator but as an active elicitor of secondary metabolism. However, the benefits were not unlimited. When the spray concentration was pushed to 150 milligrams per liter, the positive effects attenuated, indicating that excessive selenium crosses a threshold where it begins to impose stress on the plant rather than support it. This biphasic response—stimulation at moderate doses, inhibition at high doses—is a well-recognized feature of selenium biology and underscores the importance of precise dosing in any biofortification program.

The transcriptome analysis provided the mechanistic depth that elevates the study beyond simple agronomy. Sequencing revealed that the differentially expressed genes between selenium-treated and control fruits were predominantly enriched in the phenylpropanoid and flavonoid biosynthesis pathways. The phenylpropanoid pathway is the metabolic superhighway of plant secondary chemistry: it begins with the amino acid phenylalanine and branches into an enormous diversity of compounds, including lignins, flavonoids, and anthocyanins, many of which serve as antioxidants, pigments, and defense molecules. The finding that selenium treatment upregulates genes in these pathways, and that this transcriptional shift correlates consistently with the measured increases in flavonoid and anthocyanin content, provides a coherent causal narrative: selenium signals the fruit to invest more heavily in its antioxidant chemical arsenal, and the genes encoding the biosynthetic enzymes respond accordingly.

This mechanism resonates with a growing body of literature on selenium’s elicitor-like effects across horticultural crops. Foliar selenium applications have been shown to enhance anthocyanin biosynthesis in purple lettuce, activate phenylpropanoid metabolism in peach, improve quality and nutrient profiles in citrus, blueberries, strawberries, pomegranate, kiwifruit, and table grapes, and modulate postharvest quality in apples. What the new study adds is a complete chain of evidence—from field application through fruit chemistry to gene expression—in a fruit species that had not previously been examined in this context. The consistency of the transcriptomic data with the biochemical measurements strengthens the conclusion that the flavonoid pathway is a genuine target of selenium signaling in Cerasus humilis, rather than an incidental correlation.

The practical implications are considerable. For growers of Chinese dwarf cherry, the study offers a targeted cultivation protocol: foliar spraying of 120 milligrams per liter sodium selenite at the young fruit and fruit expansion stages provides selenium biofortification and quality enhancement simultaneously, without genetic modification, without altering the crop, and with an input cost measured in pennies per tree. For nutrition policy, it demonstrates that selenium-deficient regions could potentially address local micronutrient gaps by fortifying locally adapted fruit crops rather than relying exclusively on staple cereals. And for the broader field of biofortification research, the study reinforces the emerging view that selenium is not just a nutrient to be accumulated but a metabolic lever that can be pulled to enhance the nutraceutical value of foods.

The authors are appropriately cautious about scaling up. Their conclusions apply to the ‘Jinou-2’ cultivar under the single-site field conditions of this study, and they emphasize that multi-site verification is required before large-scale popularization. Cultivar-specific responses, regional soil and climate variations, and the cumulative selenium load in orchard ecosystems all warrant further investigation. Nevertheless, the study marks a significant step forward in the science of fruit biofortification, showing that with a precisely timed spray of a simple selenium salt, a small cherry with an outsized nutritional reputation can be made even more remarkable—one gene, one flavonoid, and one harvest at a time.

Subject of Research: Foliar selenium biofortification and flavonoid metabolism in Cerasus humilis fruit

Article Title: Foliar selenium spray enhances selenium content, antioxidant capacity and flavonoid metabolic pathway in Cerasus humilis fruit

Article References: Lv, J., Liu, N., Dang, Y., Jia, L., Zhang, S., Wang, P., Lee, C. T., Mu, X., & Zhang, J. (2026). Foliar selenium spray enhances selenium content, antioxidant capacity and flavonoid metabolic pathway in Cerasus humilis fruit. Plant and Soil. https://doi.org/10.1007/s11104-026-09097-z

Image Credits: AI Generated

DOI: 10.1007/s11104-026-09097-z

Keywords: selenium biofortification, Cerasus humilis, Chinese dwarf cherry, sodium selenite, flavonoid biosynthesis, anthocyanins, antioxidant capacity, phenylpropanoid pathway, transcriptome analysis, fruit quality, organic selenium, foliar spray

A-to-I RNA editing is catalyzed by the ADAR family of enzymes, primarily ADAR1 and ADAR2, which chemically convert adenosine bases to inosine within RNA transcripts. Because the cellular machinery reads inosine as guanosine, this single change can rewrite the meaning of a gene: it can swap amino acids in proteins, alter splice sites, create or destroy start and stop codons, reshape RNA folding, and modulate microRNA targeting. In humans, millions of editing sites dot the transcriptome, with the vast majority clustered in repetitive elements such as Alu sequences, where paired inverted repeats form the double-stranded RNA substrates that ADAR enzymes prefer. Editing in these repetitive regions also helps cells distinguish their own RNA from foreign double-stranded RNA, preventing inappropriate immune activation.

The functional stakes are high. Aberrant A-to-I editing has been implicated in amyotrophic lateral sclerosis, autism spectrum disorder, schizophrenia, epilepsy, depression and multiple cancers, and dynamic editing levels are known to vary across tissues, developmental stages and species. Because editing levels, defined as the fraction of adenosines converted to inosine at a given site, are the currency of nearly every study in this field, accurate measurement is foundational. Yet while considerable effort has gone into developing methods to identify editing sites from sequencing data, far less attention has been paid to whether the quantification of editing levels itself is trustworthy.

To test this, the team, led by Shi Cheng and Yulong Song of Guangzhou Medical University alongside colleagues at Sun Yat-sen University, performed matched short-read and long-read cDNA RNA sequencing on two human cell lines, HEK293T and U2OS. The short-read data were generated on an Illumina NovaSeq 6000 platform using both polyA-selected and rRNA-depleted library strategies, producing reads of roughly 150 nucleotides. The long-read data were produced on Oxford Nanopore Technologies PromethION sequencers, which capture full-length cDNA molecules with median clean read lengths of 812 to 878 nucleotides. Both approaches were anchored to a curated reference list of 2,858,028 human A-to-I editing sites compiled from the group’s previous work.

The results were striking. In HEK293T cells, long-read sequencing identified 3,897 editing sites measured significantly higher than by polyA-selected short-read sequencing, against only 445 sites measured higher by the short-read approach, an approximately 8.8-fold difference in the number of sites. Globally, the median editing level estimated by long reads was about 2.3 times that from short reads. The pattern held for sites in Alu elements, in repetitive non-Alu regions and in nonrepetitive regions alike. Most dramatically, at nonrepetitive sites the median short-read estimate was 0 percent, implying no editing at all, whereas long-read sequencing revealed a true median level of about 2.1 percent. Parallel comparisons using rRNA-depleted short-read libraries, and independent experiments in U2OS cells, reproduced the same directional bias, with long reads detecting roughly 6.6 to 9.0 times more significantly higher-measured sites.

To rule out artifacts, the researchers ran an extensive battery of controls. They raised coverage thresholds from 30 to 40, 50 and 60 reads per site, tightened the base-quality cutoff for long reads, and removed PCR duplicate reads; the underestimation by short reads persisted in every case. As expected, no meaningful difference emerged between polyA-selected and rRNA-depleted short-read libraries, or between the two cell lines, confirming that the bias tracks with sequencing technology rather than biology. A full-length DNA and RNA amplicon sequencing experiment provided direct validation: DNA amplicons, which cannot carry RNA edits, showed editing levels near zero, while RNA amplicons and long-read cDNA sequencing agreed with each other and both substantially exceeded the short-read estimates.

The mechanistic explanation converged on read length and its effect on genome alignment. Because short reads carry less sequence context, they are more likely to map to the wrong place in the reference genome, particularly within repetitive regions where many loci look alike. By computationally constructing artificial short-read datasets of 50, 75, 100 and 150 nucleotides from their own 150-nucleotide data, the team showed a strongly positive correlation between read length and measured editing level: longer reads yielded higher estimates, with fold differences reaching 12.1 between 150-nt and 50-nt reads. Crucially, when they truncated reads at the alignment stage rather than the sequence stage, recalculating mapping coordinates so that no re-alignment occurred, the correlation vanished. This pinpointed misalignment, not any property of the sequences themselves, as the culprit.

The alignment analysis went further. As read lengths decreased, millions of reads shifted from uniquely mapped to multiply mapped or unmapped statuses, and the counts of these misalignment categories correlated negatively with measured editing levels and with the Alu editing index, a widely used global metric computed with the RNAEditingIndexer tool. The same positive relationship between read length and editing quantification appeared in public short-read data from HEK293T, U2OS, HeLa, HepG2, K562, A549 and U87 cells, and in artificial datasets derived from long-read data segmented to shorter lengths, indicating the effect is universal across platforms and laboratories.

The generality of the finding was then tested against independent public resources. A paired short-read and long-read dataset covering eight human lung cancer cell lines showed higher editing quantification by long reads in every line, with nonrepetitive sites again registering zero percent under short reads versus roughly two percent under long reads. Cross-study comparisons using long-read data from GM12878 and HeLa cells against ENCODE and other short-read datasets revealed 23.8-fold and 6.4-fold excesses, respectively, of sites measured higher by long reads. The authors conclude that long-read RNA sequencing is preferable for accurate quantification of A-to-I editing levels, while acknowledging its higher cost; for laboratories constrained to short reads, they recommend raising coverage depth, restricting analyses to uniquely mapped reads, or validating key sites with full-length amplicon or Sanger sequencing.

Beyond editing, the study raises a caution for transcriptomics at large. Since read-length-dependent misalignment degrades any measurement that depends on precise genomic placement, splicing and gene expression estimates from short-read data may also harbor systematic errors that warrant closer scrutiny. Given that A-to-I editing shapes nearly 85 percent of the human transcriptome and is an emerging target for RNA-based therapeutics, the message is clear: the technology chosen to read RNA does not merely observe biology, it shapes what biology appears to say.

Subject of Research: Comparison of short-read and long-read RNA sequencing for accurate quantification of A-to-I RNA editing levels

Article Title: Short-read RNA-seq yields lower estimates of A-to-I RNA editing levels than long-read cDNA sequencing

Article References: Cheng, S., Qi, Y., Ya, J., Xia, L., Zhang, W., Xiong, Q., Liu, Q., Zhang, J., & Song, Y. (2026). Short-read RNA-seq yields lower estimates of A-to-I RNA editing levels than long-read cDNA sequencing. Advanced Biotechnology, 4(3), Article 27. https://doi.org/10.1007/s44307-026-00123-w

Image Credits: AI Generated

DOI: 10.1007/s44307-026-00123-w

Keywords: A-to-I RNA editing, RNA-seq, short-read sequencing, long-read sequencing, ADAR, alignment accuracy, read length, transcriptome, Alu repeats, cancer cell lines, Oxford Nanopore, quantification bias