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PubMed2026

Ultraviolet-B-induced OsKOL4 promotes ABA accumulation by inhibiting OsABA8ox1 and OsABA8ox2 expression.

Ultraviolet-B (UV-B) light is a component of sunlight that influences plant survival and adaptation. UV-B induces plants to regulate their phenotypes and metabolism to increase resistance to UV-B and associated stresses. Abscisic acid (ABA) metabolism and signaling are important for plant responses to UV-B. However, the mechanisms underlying UV-B-induced ABA accumulation and signaling in rice remain poorly understood. Here, we report that ENT-KAURENE OXIDASE LIKE 4 (OsKOL4) regulates UV-B-induced responses and ABA biosynthesis. UV-B activates OsKOL4 expression via OsbZIP48, an ELONGATED HYPOCOTYL 5 (HY5) homolog that directly binds to the OsKOL4 promoter. Rice plants overexpressing OsKOL4 exhibit UV-B-induced phenotypes under normal conditions, along with ABA overaccumulation phenotypes resulting from increased ABA levels. Moreover, UV-B promotes ABA accumulation by inhibiting the expression of the ABA 8'-HYDROXYLASE1 and ABA 8'-HYDROXYLASE 2 (OsABA8ox1/2) genes through OsKOL4. OsKOL4 interacts with the transcription factor AP2/ERF ON CHROMOSOME 3 (OsAPE3), which in turn represses the transcription of OsABA8ox1/2. Furthermore, both UV-B and OsKOL4 enhance the binding of OsAPE3 to the OsABA8ox1/2 promoters. Collectively, our findings demonstrate that the OsKOL4-OsAPE3 module regulates ABA homeostasis in response to UV-B signaling by reducing ABA catabolism.

Abscisic Acid↗

PubMed2026

CaMYB121-CaABF2 negative feedback loop modulates CaNHX2 expression to confer salt tolerance in pepper.

Salt stress is a major abiotic factor that severely restricts pepper (Capsicum annuum) production. Although abscisic acid (ABA) is vital for salt tolerance, the transcriptional regulatory networks governing ABA-mediated salt defense remain largely unknown. Here, we uncovered a negative feedback loop between CaMYB121 and CaABF2.1/2 that modulates the expression of CaNHX2.1/2/3, thereby enhancing salt tolerance in pepper plants. RNA-seq analysis revealed that CaMYB121 displayed an expression pattern consistent with that of CaNHX2 after salt treatment. Silencing CaMYB121 markedly reduced salt tolerance and inhibited root growth. Mechanistically, CaMYB121 directly binds to the CaNHX2 promoter to activate transcription, thereby promoting salt resilience. Salt stress also robustly triggered ABA signaling genes, with CaABF2.1/2 displaying expression patterns closely mirroring those of CaMYB121. Transient silencing of CaABF2.1/2 results in phenotypes similar to those observed with CaMYB121 suppression. Notably, CaMYB121 activates CaABF2.1/2 transcription by binding to its promoters, whereas CaABF2.1/2 represses CaMYB121 expression by directly targeting its promoter, forming a self-regulating feedback loop that prevents excessive defense activation. Collectively, our findings reveal a CaMYB121-CaABF2 feedback circuit that dynamically balances growth and defense to optimize salt tolerance in pepper plants.

Salt Tolerance↗

PubMed2026

Exogenous ABA enhances cold tolerance of Rhododendron yedoense var. poukhanense under subzero temperature: integrating physiology, transcriptome, and proteome.

Low temperature limits the growth and ornamental value of evergreen shrubs. Rhododendron yedoense var. poukhanense, an important ornamental shrub from Northeast China, frequently suffers freezing damage during winter. While exogenous abscisic acid (ABA) enhances cold tolerance in many plants, its molecular mechanisms at subzero temperatures remain poorly understood in non-model species lacking chromosome-level reference genomes. This study investigated the effects of exogenous ABA on freezing tolerance in R. yedoense var. poukhanense at -4 °C using an integrated physiological, transcriptomic, and proteomic approach. Cutting seedlings were subjected to four treatments: CK (22°C control), A (22°C + ABA), LT (-4°C), and ALT (-4°C + ABA). Photosynthetic pigments, osmotic regulation substances, antioxidant enzyme activities, and malondialdehyde (MDA) content were measured. Transcriptome sequencing and quantitative proteomics were performed, and transcriptome data were validated by quantitative real-time PCR (qRT-PCR) of 15 selected genes. ABA pretreatment reduced visible cold injury severity, partially preserved photosynthetic pigments, decreased MDA content by 28.7%, and promoted recovery of catalase (+43.6%), superoxide dismutase (+31.1%), and peroxidase (+20.0%) activities under freezing stress. Transcriptome analysis revealed 8, 444 differentially expressed genes (DEGs) in LT versus CK and 6, 481 DEGs in ALT versus CK, representing a 23% reduction in transcriptional reprogramming scope attributable to ABA priming. The ALT versus LT comparison identified only 1, 690 additional DEGs, indicating that most cold-responsive genes were pre-activated during the ABA priming phase. Proteome analysis identified 1, 461 differentially expressed proteins (DEPs) in ALT versus CK. Integrated analysis revealed extensive post-transcriptional regulation, with transcript-protein concordance of only 1.0-4.1%, and co-enriched Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways in both omics layers. qRT-PCR validation confirmed high reliability of the transcriptome data (R2 = 0.8500). These findings demonstrate that exogenous ABA enhances freezing tolerance through multi-layered molecular regulation encompassing transcriptional buffering, translational reprogramming, and functional reallocation from photosynthesis to stress protection. This study provides the first integrated physiology-transcriptome-proteome framework for ABA-mediated freezing tolerance in an evergreen ornamental shrub and offers theoretical support for ABA-based winter protection strategies.

Rhododendron yedoense var. Poukhanense↗

PubMed2026

Integrated methylome and transcriptome analysis provides insight into DNA methylation-mediated networks in sexual dimorphism of Vernicia montana.

BACKGROUND: Sexual dimorphism is fundamental to reproduction in dioecious plants and is regulated by both genetic and epigenetic mechanisms. DNA methylation is a central epigenetic mark known to influence phenotypic variation in plants. However, its specific role in shaping sexual dimorphism in dioecious trees remains poorly understood. To address this question, we performed integrated genome-wide DNA methylome and transcriptome analyses of four tissue types in the dioecious tung tree (Vernicia montana), including male and female flower buds and their corresponding leaves. RESULTS: Our analysis revealed distinct DNA methylation patterns between male and female tissues. Notably, the coordination between DNA methylation reprogramming and transcriptional regulation appeared to be more strongly associated with reproductive development than with vegetative growth in V. montana. We identified a set of sex-biased genes that may reflect different reproductive strategies between the sexes. Further analysis identified several key transcription factors (TFs) potentially associated with promoter differentially methylated regions (DMRs), including flowering-time regulators (e.g., FRS5, REM16, and VRN1) and TFs involved in hormone signaling pathways such as jasmonic acid, auxin, and salicylic acid signaling. Cis-regulatory element analysis showed that some promoter DMRs overlapped with hormone response elements related to abscisic acid, auxin, and gibberellin. Co-expression network analysis further revealed potential regulatory correlations among promoter DMR-mediated TFs, hormone-responsive pathways, and key floral development regulators. CONCLUSIONS: Collectively, our results suggest that interactions among DNA methylation, transcriptional regulation, and hormone-responsive pathways may contribute to the establishment of sexual dimorphism in V. montana. This study provides the first integrated view of these regulatory layers in V. montana and supports a species-specific regulatory framework for understanding the epigenetic basis of sexual dimorphism in this economically important dioecious tree. The proposed framework is based on multi-omics analyses and warrants further validation through targeted functional studies.

DNA Methylation↗

PubMed2026

Plant nitrogen nutrition: enhancing plant resilience to abiotic stresses.

Nitrogen (N) is not only an essential macronutrient for plant growth and development but also functions as a pivotal signaling molecule that orchestrates adaptive responses to various abiotic stresses, including acidic stress, aluminum toxicity, salinity, drought, and extreme temperatures. This review synthesizes recent advances in our understanding of the molecular mechanisms by which N signaling, mediated by different N forms (e.g., NH4+ and NO3-), integrates with core stress-response pathways. We specifically discuss the genetic crosstalk between N sensing and key signaling cascades, including abscisic acid (ABA) signaling, the salt overly sensitive (SOS) pathway, and reactive oxygen species (ROS) homeostasis. The review details how this integration modulates physiological and transcriptional reprogramming through central regulators such as NIN-like proteins (NLPs), calcineurin B-like protein (CBL)-interacting protein kinase (CIPK), and the target of rapamycin (TOR) kinase, ultimately optimizing the trade-off between growth and tolerance. By establishing a unified genetic and molecular framework, this review aims to provide a theoretical basis for developing novel strategies in precision N management and molecular breeding to synergistically enhance N use efficiency (NUE) and abiotic stress tolerance in crops.

Nitrogen↗

PubMed2026

Mining the sHSP20 (small heat-shock protein) gene family in finger millet (Eleusine coracana (L.) Gaertn.): structural, evolutionary and predicted abiotic-stress-responsive insights.

Small heat-shock proteins (sHSPs, the HSP20 family) are ATP-independent molecular chaperones that hold partially unfolded substrates and protect the proteome during heat and other abiotic stresses; every member is defined by a conserved α-crystallin domain (ACD). Finger millet (Eleusine coracana) is a climate-resilient, calcium-rich allotetraploid cereal of the semi-arid tropics whose HSP20 repertoire had not been catalogued. The present study is an entirely computational (in silico) analysis of the chromosome-scale reference genome of finger millet (NCBI GenBank assembly GCA_032690845.1, cultivar KNE 796-S). Mining the predicted proteome with the ACD profile (Pfam PF00011) and confirming every candidate by NCBI CD-search recovered 76 non-redundant ACD-bearing HSP20 genes (EcHSP20-1-EcHSP20-76). Based on phylogeny and TargetP-predicted localization, the members were classified into ten subfamilies: seven cytosolic/nuclear classes (C-I to C-VII, 60 members) together with chloroplastic (11), mitochondrial (3) and endoplasmic-reticulum (2) groups. The proteins ranged from 110 to 355 amino acids (12.1-39.2 kDa) with theoretical pI of 4.85-9.69. The 76 loci were distributed over 14 of the 18 chromosomes and were conspicuously absent from chromosomes 8 A, 8B, 9 A and 9B, with pronounced clustering on chromosomes 1, 2, 3 and 6. Duplication analysis detected 149 paralogous pairs (49 homoeologous, 80 segmental/dispersed and 18 tandem); 147 of 148 pairs for which substitution rates could be calculated returned Ka/Ks < 1 (mean 0.20), indicating strong purifying selection consistent with retention after whole-genome/allopolyploid duplication. Promoter analysis (PlantCARE) revealed enrichment of abscisic-acid-responsive (ABRE), MYB/MYC drought-related, STRE, DRE, low-temperature (LTR) and methyl-jasmonate/salicylic-acid elements, whereas canonical heat-shock elements (HSE) were not recovered. Expression profiling against a public drought transcriptome (SRP081350) showed that about half of the genes (39 of 76) are transcribed in leaf tissue, the expressed fraction being dominated by the cytosolic class C-I. This first finger-millet HSP20 catalogue provides a verified, reproducible framework and nominates computationally predicted candidate genes for future functional work on thermotolerance in cereals.

Allotetraploid↗

PubMed2026

Seed shattering habit in millets and the secrets of the abscission layer - a comprehensive review.

Though seed shattering continues to be a significant barrier affecting yield stability and harvesting efficiency in millets and other grasses, millets are increasingly acknowledged as climate-resilient, nutrient-rich 2007cereal crops with the potential to strengthen global nutritional and food security under the combined pressures of climate change, population growth, and limited natural resources. Since strong artificial selection favoured non-shattering phenotypes during domestication, seed shattering, an adaptive trait in wild species that promotes seed dispersal through the formation and activation of specialised abscission layers, became a distinguishing feature of cultivated cereals. With a focus on the morphological, physiological, hormonal, and genetic modulation of the abscission zone, this article summarizes the state of the art regarding seed shattering in millets. Abscission layer morphology, location, and lignification vary greatly among grasses, from well-defined lignified zones in rice and sorghum to non-lignified and anatomically subtle zones in Setaria and Panicum species. Cell wall-modifying enzymes like polygalacturonases, cellulases, expansins, and pectin methylesterases that mediate middle lamella degradation are modulated by coordinated hormonal signalling involving auxin, ethylene, and abscisic acid, which controls the timing and progression of cell separation at the physiological level. Domestication-related genes, including SH1, qSH1, SH4, and LES1, demonstrate convergent evolutionary mechanisms controlling abscission layer development in a variety of grass lineages at the molecular level. Understanding these regulatory networks has been greatly enhanced by recent developments in transcriptomics, functional genomics, and genome sequencing in both model species and underused millets. The role of millets as climate-smart cereals for sustainable future agriculture is reinforced by the integration of anatomical, physiological, and genetic insights, which offer a solid basis for targeted breeding and genome-editing strategies intended to improve seed retention, enhance yield stability, and increase harvest efficiency.

Abscission Layer↗

PubMed2026

Research progress on the regulatory mechanisms of the PSY promoter.

Carotenoids are essential pigments in the plant photosynthetic apparatus, functioning in light harvesting, photoprotection, and signal transduction, and serving as precursors of vital nutrients such as vitamin A. Phytoene synthase (PSY) is the first rate-limiting enzyme in the plant carotenoid biosynthetic pathway, and its transcriptional regulation primarily depends on cis-acting promoter elements, associated transcription factors, and epigenetic status. The PSY promoter region contains core cis-elements as well as multiple light-, hormone-, and stress-responsive elements, which collectively function as key regulatory sites governing spatiotemporal expression. This review systematically summarizes recent advances in PSY promoter regulation by plant hormones (e.g., abscisic acid, ethylene, jasmonic acid), environmental factors (light signaling, temperature, salinity, and drought), and epigenetic mechanisms (DNA methylation, histone modifications, and chromatin remodeling). In addition, the application of transgenic and biotechnological approaches to PSY promoter regulation is further summarized. Including promoter sequence engineering with precise editing of cis-elements and promoter-targeted CRISPR activation/interference (CRISPRa/i) for tunable transcriptional control. Emphasis is placed on how these signals are integrated at the promoter level. Deeper insights into these mechanisms will provide both theoretical foundations and practical strategies for enhancing carotenoid accumulation and stress tolerance in crops through molecular design.

Promoter Regions, Genetic↗

PubMed2026

Genome-wide identification of the carotenoid cleavage dioxygenase gene family in wheat and analysis of the TaDREB-7A-TaNCED9a regulatory module conferring drought tolerance.

Carotenoid cleavage dioxygenases (CCDs) play critical roles in plant growth, development, and abiotic stress responses, yet their genome-wide identification and drought response mechanisms remain unexplored in wheat. In this study, 34 TaCCD genes were identified in wheat, distributed across 15 chromosomes and phylogenetically classified into five subfamilies. Gene structure analysis indicated that members within each subfamily shared conserved motifs and similar intron-exon arrangements. Cis-regulatory element analysis suggested the potential roles of these genes in stress adaptation, developmental processes, and hormone signaling. Moreover, prediction of tertiary structures and protein-protein interactions revealed unique structural features and potential interacting partners of the TaCCD proteins. In addition, TaNCED9a, a member of the TaCCD family, showed the highest transcript level in wheat roots among all detected TaCCD genes and was significantly induced by drought stress. Subcellular localization assay indicated that TaNCED9a was located in chloroplasts. Downregulation of TaNCED9a expression led to reduced drought resistance in wheat, accompanied by an accumulation of reactive oxygen species and a decrease in endogenous abscisic acid levels. Using yeast one-hybrid, dual-luciferase, and tobacco transient co-expression assays, the upstream regulatory factor TaDREB-7A was identified, which can regulate the expression of TaNCED9a. Additionally, a KASP molecular marker was developed to identify the superior haplotype TaNCED9a-HapI, which exhibited a significantly higher germination rate compared to TaNCED9a-HapII under drought conditions, and was predominant in wheat. These results offer valuable insights into the TaCCD gene family's response mechanisms to drought stress in wheat, simultaneously identifying promising genetic resources for enhancing drought tolerance through molecular breeding.

CCD↗

PubMed2025

Spatial Mapping and Interactome Profiling of m6A-Modified R-Loops via Chemically Inducible Split-APEX2 Proximity Labeling.

m6A-Modified R-loops (m6A-R-loops) play crucial roles in epigenetic regulation and genome stability, yet resolving their spatial distribution and protein interactomes in live cells remains challenging. To address this, we developed m6A-R-loop proximity labeling (m6A-RLPL), a chemically inducible split-APEX2 proximity labeling technology integrating dual-target recognition using the RNA-DNA hybrid binding domain of RNase H1 for R-loop targeting and m6A reader protein's YTH domain for m6A recognition, coupled with an abscisic acid (ABA)-inducible dimerization system for signal amplification. This technology revealed host m6A-R-loops enriched with nucleoli under normal conditions. When applied to herpes simplex virus (HSV) infection, it further demonstrated viral m6A-R-loops undergoing dramatic accumulation within phase-separated granules in replication compartments during late-stage infection. Proximity proteomics identified ZC3H4 and CCDC124 as essential regulators maintaining these structures, which serve as transcription sites for HSV late genes, with disruption selectively impairing viral transcription. m6A-RLPL establishes a generalizable approach for spatially resolved profiling of m6A-R-loop interactomes and organizational dynamics in living systems.

Humans↗

PubMed2024

Phased telomere-to-telomere reference genome and pangenome reveal an expansion of resistance genes during apple domestication.

The cultivated apple (Malus domestica Borkh.) is a cross-pollinated perennial fruit tree of great economic importance. Earlier versions of apple reference genomes were unphased, fragmented, and lacked comprehensive insights into the apple's highly heterozygous genome, which impeded advances in genetic studies and breeding programs. In this study, we assembled a haplotype-resolved telomere-to-telomere (T2T) reference genome for the diploid apple cultivar Golden Delicious. Subsequently, we constructed a pangenome based on 12 assemblies from wild and cultivated species to investigate the dynamic changes of functional genes. Our results revealed the gene gain and loss events during apple domestication. Compared with cultivated species, more gene families in wild species were significantly enriched in oxidative phosphorylation, pentose metabolic process, responses to salt, and abscisic acid biosynthesis process. Our analyses also demonstrated a higher prevalence of different types of resistance gene analogs (RGAs) in cultivars than their wild relatives, partially attributed to segmental and tandem duplication events in certain RGAs classes. Structural variations, mainly deletions and insertions, have affected the presence and absence of TIR-NB-ARC-LRR, NB-ARC-LRR, and CC-NB-ARC-LRR genes. Additionally, hybridization/introgression from wild species has also contributed to the expansion of resistance genes in domesticated apples. Our haplotype-resolved T2T genome and pangenome provide important resources for genetic studies of apples, emphasizing the need to study the evolutionary mechanisms of resistance genes in apple breeding.

Malus↗

PubMed2025

Polyploidy-mediated variations in glutamate receptor proteins linked to Fusarium wilt resistance in upland cotton.

Cotton production in the US faces a serious threat from Fusarium oxysporum f. sp. vasinfectum race 4 (FOV4), a soil-borne fungus causing Fusarium wilt by infecting the roots and vascular system of susceptible cotton, leading to rapid wilting and death. Here, we investigate genetic mechanisms of resistance to FOV4 in the highly resistant upland cotton genotype "U1" using an early-generation segregating biparental population ("U1" × "CSX8308") with comprehensive genomic resources. Reference-grade genomic assemblies of the parents revealed minor structural variations between "U1" haplotypes, a high degree of collinearity at chromosome synteny and micro-synteny levels, and significant divergence from "CSX8308" with 8.9 million SNPs. QTL analysis identified significant markers on chromosomes D03 and A02 linked to reduced Fusarium wilt severity. Within these regions, two glutamate-receptor-like (GLR) genes showed structural variation and overlapped between translocated segments on A02 and D03, suggesting a rare but important reinforcing effect of parallel evolution between susceptible and resistant genotypes. Transcriptome profiles of "U1" under FOV4 infection reveal activation of calcium-binding proteins and transcription factors regulating plant hormones (ethylene, abscisic acid, jasmonic acid, and salicylic acid), along with enzymes involved in cell wall remodeling and phytoalexin production. Advancing cotton improvement depends on incorporating durable genetic disease resistance into high-yielding, high-quality cultivars.

Fusarium↗

PubMed2025

Genomics control of biostimulant-induced stress tolerance and crop yield enhancement.

Biostimulants are changing modern agriculture, as they have the potential to secure healthy and sustainable food production while preserving the environment. They have two main biological effects: growth promotion and stress protection. Both effects can lead to enhancement of the yield and improvement of the marketable grade of the produce in crops, without compromising crop quality. Their use increased exponentially in the past decade, as they are highly efficient, ecologically friendly (non-toxic, biodegradable), and applicable to all major crops. While exponential data on the physiological mechanisms of stress protection is accumulating in recent years, the information as to how biostimulants act at the molecular level is still rather limited. Here we review the growing evidence of the biostimulants role in stress protection and yield enhancement of crops, as well as the recent transcriptomic and metabolomic data, which indicate biostimulants' molecular mode of action. In particular, we outline the role of genes encoding signaling components, plant hormones (abscisic acid, brassinosteroids, and ethylene), genes encoding transcription factors from ERF, WRKY, NAC, and MYB families, and genes related to growth, photosynthesis, and stress response. Finally, we describe strategies to study the genetic and genomics control of biostimulants mode of action, with foci on stress tolerance and yield enhancement. In Arabidopsis, established systems for biostimulants-induced protection against drought and oxidative stress will allow both forward and reverse genetics approaches to identify key genes from the biostimulants network. Mutations in such genes compromise the stress-protective effect of biostimulants. In major crops such as pepper and tomato, large Genome Wide Association Studies (GWAS) panels can be utilized to study crops responses to biostimulants in terms of drought tolerance, fruit qualities, and yield in order to pinpoint genes controlling biostimulants-induced stress protection and yield enhancement. The combination of these approaches allows identification and verification of important genes involved in the pathways of biostimulant-induced stress protection and yield enhancement, as well as deciphering parts of the intricate biostimulant-signaling network.

Crops, Agricultural↗

PubMed2025

Comprehensive analysis of DNA methylome and transcriptome reveals the epigenetic regulation of nitric oxide treatment in delaying apricot fruit senescence.

Apricot produces climacteric fruit, which are perishable after harvest. To elucidate the regulatory role of NO treatment through DNA methylation in post-harvest senescence, apricot fruits were treated with 0.2 mmol/L sodium nitroprusside (SNP) solution for 10 min, with distilled water treatment serving as the control. Treated fruits were then stored at 25°C and 80% relative humidity. Changes in appearance quality, physiological parameters, metabolome profiles, transcriptome dynamics, and DNA methylation patterns were analyzed before and after storage. Results showed that NO treatment delayed apricot softening, increased flavonoid metabolite accumulation, and reduced lipid and abscisic acid accumulation, with these effects correlated to the expression of specific genes and transcription factors. This work reveals the epigenetic regulatory mechanism underlying NO treatment delaying ripening and senescence. Further analysis revealed that the transcription levels of ACO, PAL, UFGT-like, NCED1, PP2C, MYB21, CCoAOMT-like, CYP707A, and ZNF7-like were all correlated with DNA methylation. This indicates that SNP treatment can lead to large changes in DNA methylation levels in apricot fruits, and that the differences in gene transcription levels are associated with the occurrence of hypomethylation and hypermethylation. Collectively, these findings establish an epigenetic framework for post-harvest regulation of apricot fruit, revealing DNA methylation-mediated freshness preservation mechanisms.

DNA Methylation↗

PubMed2026

Phytohormones in fungi: inter-kingdom modulators or fungal self-controlling elements?

SUMMARYLeveraging data from innovative experimental approaches, omics technologies, and bioinformatics, we offer new insights into how fungi communicate with and perceive their environment to achieve ecological success. By integrating comparative data from both the fungal and plant kingdoms, we critically reassessed the evolutionary, biochemical, and functional landscape of phytohormones in fungi, challenging the conventional notion that these molecules serve exclusively as plant regulators or as means of communication with them. Our analysis demonstrates that fungi not only synthesize a diverse array of phytohormones-including auxins, cytokinins, gibberellins, abscisic acid, ethylene, brassinosteroids, salicylic acid, and oxylipins-but also possess hormone-sensing and signal transduction mechanisms architecturally distinct from those of plants. Employing genomics, phylogenetics, and structural analyses, the review uncovers that many hormone biosynthetic and sensing pathways in fungi are evolutionarily ancient, sometimes predating their roles in plant-fungus interactions, and that some pathways show convergence rather than direct gene homology. Fungal phytohormones regulate development, growth, and metabolism, thereby playing key functions in their ecological context. The review emphasizes that, while biosynthetic pathways tend to be highly conserved, perception and signaling mechanisms in fungi are more varied and often remain poorly understood. We conclude that fungi have an intrinsic and autonomous hormonal physiology that underpins their ecological adaptability and success. Collectively, this analysis reframes fungal biology, highlighting the need for deeper investigation into the signaling and regulatory roles of phytohormones in fungi beyond their interactions with plants.

cell signaling↗

PubMed2026

Cultivar-dependent regulation of cytokinin biosynthesis in wheat: developmental expression of TaIPT genes and hormonal crosstalk during reproductive development.

BACKGROUND: Cytokinins are key regulators of plant growth, reproductive development, and yield formation. In cereals, cytokinin biosynthesis is catalyzed by isopentenyltransferase (IPT) enzymes, yet the genomic organization and developmental regulation of IPT genes in polyploid wheat remain incompletely understood, especially at the cultivar level. RESULTS: Here, we present an integrated genomic, transcriptional, and hormonal analysis of the TaIPT gene family during vegetative and reproductive development in two wheat cultivars, awnless Kontesa and awned Ostka. Genome-wide analysis identified nine core TaIPT genes represented by 25 homoeologs distributed across the A, B, and D subgenomes, for which a unified nomenclature was established. Phylogenetic analysis resolved TaIPTs into conserved evolutionary clades corresponding to ATP/ADP-dependent and tRNA-dependent IPT groups. Expression profiling revealed distinct spatial and temporal patterns of TaIPT transcription across roots, leaves, inflorescences, and developing spikes. Several TaIPT genes showed enhanced expression during early reproductive stages, coinciding with dynamic changes in cytokinin concentrations. Comparative analyses revealed cultivar-specific expression and co-variation patterns, with Kontesa displaying more compartmentalized TaIPT expression and Ostka showing coordinated activation of multiple TaIPT genes during early grain development. Hormone profiling further indicated stage-dependent associations between TaIPT expression, cytokinin metabolism, and the balance between cytokinins and abscisic acid. These relationships are interpreted as correlative and provide a framework for future functional testing rather than direct evidence of causality. CONCLUSIONS: Together, these results provide a cultivar-focused framework for understanding the organization and regulation of cytokinin biosynthesis genes in wheat. The data highlight cultivar-dependent TaIPT expression patterns and their association with cytokinin dynamics during reproductive development, while also identifying the need for homoeolog-specific and functional validation. This study establishes a foundation for future research on cytokinin-mediated regulation of wheat growth and grain development.

Triticum↗

PubMed2026

Identification of the R2R3-MYB gene family in wild jujube (Ziziphus jujuba var. spinosa) and analysis of its expression under drought stress.

BACKGROUND: R2R3-MYB gene family serves as a pivotal regulatory factor in plant growth, development, and responses to environmental stresses. To investigate its function in the drought stress response of wild jujube (Ziziphus jujuba Mill. var. spinosa), a typical eco-economic forest species, this study performed genome-wide identification and relevant analyses of R2R3-MYB genes. RESULTS: A total of 91 R2R3-MYB genes (designated as ZjMYB1 to ZjMYB91) were identified, which were unevenly distributed across 12 chromosomes. These genes mainly encode hydrophilic and unstable proteins, 97.8% of which are localized in the nucleus. Phylogenetic analysis classified these genes into 25 clades, showing evolutionary conservation and species-specific divergence with the R2R3-MYB protein family. The expansion of the ZjMYB family is mainly characterized by segmental duplication, and all duplicated gene pairs have undergone purifying selection. ZjMYBs are widely involved in plant growth and development as well as abiotic stress responses, with the highest expression level particularly in leaf tissues; a total of 13 genes were specifically annotated as water deficit response-related genes in drought stress and abscisic acid (ABA) signaling pathways. Integrating the above analyses together with transcriptome data and qRT-PCR validation results revealed that ZjMYB5, ZjMYB53, ZjMYB57 and ZjMYB85 function as core drought-responsive genes, which display both tissue-specific and time-dependent expression patterns under drought stress. CONCLUSIONS: This study systematically elucidated the functional characteristics and regulatory network of the R2R3-MYB gene family in wild jujube, providing critical genetic resources and a theoretical basis for dissecting the molecular mechanisms underlying drought tolerance in wild jujube and breeding drought-resistant cultivars.

Ziziphus↗

PubMed2026

Genome-wide identification of the superoxide dismutase gene family in Lycium barbarum and their expression profiles under abiotic stress and phytohormone treatment.

BACKGROUND: Superoxide dismutases (SODs) are crucial metalloenzymes that constitute the first line of defense against reactive oxygen species in plants under abiotic stress. Wolfberry (Lycium barbarum) is an economically important medicinal plant with notable stress tolerance, however, a comprehensive genome-wide analysis of its SOD gene family has not yet been performed. RESULTS: We identified ten wolfberry SOD genes (LbaSODs) and classified them into three subfamilies: iron-SODs (Fe-SODs), manganese-SODs (Mn-SODs), and copper/zinc-SODs (Cu/Zn-SODs). Members within each subfamily shared conserved gene structures and motifs. Segmental duplication was the primary driver of LbaSOD expansion, with three paralogous pairs identified. Analysis of cis-regulatory elements in the promoter region revealed a predominance of stress- and hormone-responsive cis-elements, particularly ABA-responsive elements (ABREs) (22 copies) and LTR (17 copies) motifs. Tissue-specific expression profiling revealed that LbaSOD2 and LbaSOD5 expression peaked during early fruit development, whereas LbaSOD6, LbaSOD9, and LbaSOD10 were progressively upregulated through fruit maturation. Under abiotic conditions, Fe-SOD members were markedly suppressed during prolonged drought, whereas LbaSOD9 and LbaSOD10 were rapidly induced in response to salt stress. Among the phytohormone treatments, methyl jasmonate (MeJA) elicited the most pronounced response, with LbaSOD5 expression increasing by approximately 60-fold after 24 hours. Notably, abscisic acid (ABA) triggered an exceptionally strong transcriptional induction of LbaSOD5 (2.5 × 105-fold), LbaSOD10 (6 × 105-fold), and LbaSOD6 (70-fold). In addition, LbaSOD3 and LbaSOD7 transcripts were undetectable in any of the tested conditions. CONCLUSIONS: This study provides the first comprehensive characterization of the LbaSOD gene family and elucidates its hormone- and stress-responsive regulatory landscape, providing a valuable foundation for future functional investigations of LbaSOD genes in abiotic stress adaptation. The extraordinarily strong ABA-mediated induction of specific LbaSOD members, together with their tissue- and stress-specific expression patterns, highlights their potential as targets for genetic improvement of stress tolerance in wolfberry.

Lycium barbarum↗