Plasmodesmata (PD) play vital roles in plant growth and defense through controlling symplastic transport of important molecules. Here we report that a conserved COBRA-like protein, COBL3, is required for PD-mediated antiviral defense (PMAD) against divergent plant RNA viruses in wheat (Triticum aestivum) and tobacco (Nicotiana benthamiana) via positively regulating callose accumulation. The wheat COBL3 protein, TaCOBL3, interacts with the 17K movement protein (MP) of barley yellow dwarf virus-GAV (BYDV-GAV). TaCOBL3 is associated with the plasma membrane and co-locates with 17K MP at PD. Genetic analysis with overexpression and knockout lines reveals that TaCOBL3 positively regulates wheat defense against BYDV-GAV through modulating callose accumulation at PD. Interestingly, TaCOBL3 interacts with the wheat homolog of PDLP5, a conserved key PD permeability regulator in higher plants. Silencing TaPDLP5 diminishes the elevated BYDV-GAV defense conferred by TaCOBL3 overexpression in wheat. Furthermore, transient expression of TaCOBL3 promotes callose accumulation and lowers PD permeability in tobacco cells, which is, however, largely compromised when tobacco PDLP5 is silenced. Notably, BYDV 17K MP weakens the interaction between TaCOBL3 and TaPDLP5 and inhibits their callose binding activities. Finally, silencing tobacco NbCOBL3 gene decreases callose content and attenuated host defense against two tobraviruses, one potexvirus, and one hordeivirus. Overall, our study reveals a previously unknown role of COBRA-like proteins in PMAD and provides insight into how a plant viral MP sabotages PMAD through perturbing COBL3-PDLP5 interaction to facilitate virus spread through PD. The conserved COBL3 gene may represent a valuable target for engineering broad-spectrum antiviral resistance in crop plants.

Drought severely limits global wheat production, and mining drought-adaptive genetic variation is critical for molecular breeding. Here, the elite wheat cultivar Zhou8425B exhibited significantly greater drought tolerance than Chinese Spring (CS), characterized by reduced leaf wilting, enhanced antioxidant capacity, improved osmotic adjustment, and lower oxidative damage under drought stress. Comparative transcriptome analysis across multiple abiotic stresses revealed preferential enrichment of bZIP transcription factors during drought responses. Genome-wide characterization identified 253 TabZIP genes in Zhou8425B, with subgroup A predominantly associated with abscisic acid (ABA)-mediated drought signaling. Integrative differential expression and co-expression network analyses identified TabZIP200 as a central drought-responsive regulator. TabZIP200 was strongly induced by drought and consistently exhibited higher expression in Zhou8425B than in CS. Virus-induced gene silencing significantly compromised drought tolerance, accompanied by increased reactive oxygen species accumulation, reduced antioxidant enzyme activities, and suppressed expression of several drought-responsive genes. Comparative promoter analysis identified a naturally occurring single nucleotide polymorphism within an ABRE cis-element. Promoter truncation, reciprocal site-directed mutagenesis, and dual-luciferase assays demonstrated that this polymorphism is the major cis-regulatory determinant controlling drought-inducible TabZIP200 expression. Furthermore, a functional KASP marker targeting this polymorphism was validated in both a recombinant inbred line population and diverse wheat accessions, showing significant associations with enhanced drought tolerance and favorable yield-related traits. Together, these findings establish TabZIP200 as a key regulator of wheat drought adaptation and demonstrate that natural cis-regulatory variation in its promoter provides a valuable genetic resource for drought-resilient wheat breeding.

Lipoxygenases (LOXs) play vital roles in plant growth and defense. In this study, through genomic and molecular analyses, we discover a major LOX gene (LOX-A4) differentially expressed in Triticum urartu (Tu), the diploid progenitor of A subgenome in polyploid wheat. Compared to Tu accessions carrying wild type gene (LOX-A4W), those bearing mutant allele (LOX-A4m) show better growth but lower stress tolerance. These differences concur with a wider geographical distribution of LOX-A4m accessions than LOX-A4W materials in the Fertile Crescent. Interestingly, only mutant LOX-A4 alleles are detected in 3,516 worldwide tetraploid and hexaploid wheat lines; restoring LOX-A4W expression in common wheat inhibits growth but enhances stress tolerance. Furthermore, genome-wide identity-by-state analysis reveals that polyploid wheat A subgenome is more related to the A genome in 13 LOX-A4m Tu accessions. Thus, our work provides evidence that LOX gene variation shapes plant gene pools and their contributions to polyploid genome formation via regulating growth-defense trade-offs.

The introgression of entire Aegilops genomes offers a valuable approach to broadening wheat's genetic diversity. To assess its impact on dough and baking quality, this study evaluated 13 hexaploid synthetics [9 STD (AABBDD), 2 STU (AABBUU), 1 STM (AABBMM), 1 STC (AABBCC)] derived from Triticum turgidum and diploid Aegilops species (genomes D, U, M, C). All lines exclusively expressed Aegilops-derived Glu-1 subunits. The STU, STM, and STC lines demonstrated superior processing quality─including higher protein content, sedimentation value, and improved gluten properties─compared to most STD lines. Paradoxically, these traits did not translate to better end-use quality. STU lines, despite strong dough properties, yielded the poorest biscuits and lowest-volume bread. In contrast, STM 10 maintained balanced glutenin ratios and soft wheat characteristics, resulting in superior bread- and biscuit-making performance. While certain Aegilops genomes improve processing traits, their effect on end-product quality is complex and genotype-specific, highlighting STM 10 as a promising resource.

Aphids are among the most common insect pests that reduce crop production worldwide. However, the breeding of aphid-resistant crops is currently hindered by the scarcity of resistance genes. This problem is particularly significant in sorghum, for which resistant cultivars are urgently needed to control the aphid Melanaphis sorghi (MES). Here, we report map-based cloning of RMES1A and RMES1B, which encode two atypical resistance proteins that confer strong defense against MES. Analysis of knockout mutants and natural variations demonstrated that RMES1A and RMES1B are both required for sorghum resistance against MES. Both genes are induced by MES feeding, specifically in sclerenchyma cells and vascular bundles. RMES1A/RMES1B interact with the sorghum aphid protein MsEF1 to form a functional complex in sorghum cells, leading to key defense responses such as the H2O2 burst and enhanced callose deposition. Accordingly, silencing of MsEF1 expression by RNA interference disrupted RMES1A/RMES1B-mediated resistance, as evidenced by significantly greater growth and fecundity of MES aphids on a resistant cultivar. Structural modeling predicted that RMES1A/RMES1B possess a potential nucleotide-binding domain and two leucine-rich repeat domains but lack the coiled-coil or Toll/interleukin-1 receptor/resistance domains observed in typical nucleotide-binding leucine-rich repeat immune receptors (NLRs). Moreover, RMES1A/RMES1B and their homologs form a distinct cluster in a phylogenetic tree of plant NLRs and likely represent a new type of plant NLR. Our work thus reveals new resistance genes that can be used to investigate and improve immunity against insect pests in sorghum and other crops.

This commentary spotlights landmark work from Guo et al. resolving the structure of the octameric resistosome formed by the active CCG10-nucleotide-binding leucine-rich repeat (NLR) immune receptor WAI3, which triggers sustained, multi-phasic Ca2+ influx. This fills a major knowledge gap regarding EDVID-lacking plant NLRs and provides insight into plant effector-triggered immunity.

Plant viruses frequently cause severe economic losses in worldwide crop production. Developing broad-spectrum resistance is the most efficient approach for controlling plant viral diseases. In this work, we found that the 17K protein of barley yellow dwarf viruses (BYDVs), which has multiple functions in viral pathogenesis including acting as a viral suppressor of gene silencing (VSR), interacted with plant methionine synthase (MS), the last enzyme in the methionine cycle. Silencing HvMS gene expression enhanced BYDV symptoms and viral gene expression in barley. In contrast, overexpressing HvMS1 in wheat, another important host of BYDVs, attenuated disease symptoms and decreased viral genome proliferation. Interestingly, the γb VSR of barley stripe mosaic virus (BSMV) also interacted with HvMS protein, and HvMS1 overexpression lines likewise exhibited improved BSMV resistance. Further investigations uncovered that the VSRs of potato virus X (PVX) and tobacco rattle virus (TRV) could interact with the MS protein of Nicotiana benthamiana; lowering NbMS gene expression by genome editing reduced tobacco resistance to PVX and TRV, whereas the reverse was observed in HvMS1 overexpression tobacco lines. Finally, we showed that HvMS1 could counteract the VSR function of 10 distinct RNA and DNA viruses by obstructing their ability to revive GFP expression in 16c tobacco, suggesting that plant MS protein may act broadly in disrupting the anti-gene silencing activities of VSRs. Altogether, our data suggest that plant MS protein positively regulates host defence to diverse viruses through inhibiting their VSRs, thus providing a promising target for engineering broad-spectrum antiviral resistance in crops.

The sorghum aphid (Melanaphis sorghi), a phloem-feeding insect pest, causes severe economic losses in sorghum-producing regions worldwide. During feeding, aphids secrete salivary proteins with potential effector functions that play pivotal roles in plant–insect interactions. However, relatively few secreted proteins and effectors have been characterized in M. sorghi. In this study, proteomic analysis of aphid-infested sorghum leaves identified 69 putative aphid-derived proteins. Bioinformatic analyses were subsequently used to predict signal peptides within these proteins. Among the five candidates with signal peptides, MsSP1 was further confirmed to be delivered into sorghum tissues during aphid feeding by immunoblotting using a specific anti-MsSP1 antibody. Functional characterization revealed that silencing the MsSP1 gene in aphids by RNAi interference significantly reduced aphid fitness on sorghum. Moreover, transient expression of MsSP1 in Nicotiana benthamiana suppressed cryptogein-induced cell death and hydrogen peroxide accumulation, indicating that MsSP1 interferes with plant immune responses. Collectively, these results suggest that MsSP1 may act as a virulence effector that enhances aphid performance while suppressing host defense. This study expands current knowledge of plant–aphid interactions and provides new insights that may facilitate the development of sustainable pest-management strategies.

The sorghum aphid (Melanaphis sorghi), a phloem-feeding insect, is a major pest affecting sorghum production. Despite advances in understanding plant resistance mechanisms, the molecular responses of aphids to resistant host plants remain poorly characterized. Here, we aimed to elucidate transcriptional changes in sorghum aphids feeding on the resistant sorghum variety HN16 and to identify key aphid regulatory genes involved in host adaptation. RNA-seq analysis identified 1,388 differentially expressed genes (DEGs) in aphids feeding on HN16. Expression profiling revealed coordinated regulation of genes involved in apoptosis and detoxification. Through weighted gene co-expression network analysis (WGCNA), 10 candidate response genes were identified. Notably, knockdown of the DEG MsCathB1, encoding a cathepsin B-like protease, significantly impaired aphid fitness on resistant plants. Functionally, MsCathB1 also suppressed cryptogein-induced plant cell death and hydrogen peroxide accumulation. These findings suggest that sorghum aphid responses to host resistance are closely linked to apoptosis-related pathways, and that MsCathB1 may function as a virulence effector modulating both aphid performance and plant immunity. This work provides new insights into aphid-host interactions and supports the development of RNAi-based strategies for aphid control.

Plants deploy sophisticated adaptive mechanisms to mitigate the detrimental effects of abiotic stresses (drought, salinity, temperature extremes, and heavy metals) and biotic stresses (pathogens and senescence) on growth and productivity. Central to these responses are transcription factors (TFs) that orchestrate stress-responsive gene networks. Among TF families, MADS-box proteins, characterized by their evolutionarily conserved DNA-binding domain, function as pivotal regulators of developmental plasticity and stress adaptation. While recent advances have clarified their roles in abiotic stress tolerance, a systematic integration of their functions in biotic stress responses has yet to be achieved. This review synthesizes current knowledge on how MADS-box TFs mediate plant adaptation to both abiotic and biotic stresses through the regulation of intricate transcriptional networks. By integrating these multifaceted insights, we advance toward a unified understanding of the molecular mechanisms by which MADS-box TFs coordinate plant responses to dual environmental challenges. Our analysis provides mechanistic insights into enhancing plant resilience through the targeted modulation of MADS-box genes and their regulatory networks. We further propose translational strategies for crop improvement, focusing on molecular breeding approaches to engineer stress-tolerant varieties that balance stress adaptation with developmental processes. This comprehensive assessment establishes MADS-box TFs as master regulators at the stress-development interface and proposes novel biotechnological avenues for sustainable agriculture.

Unreduced gametes (UGs), also known as 2n gametes, retain the somatic chromosome number and represent a fundamental mechanism for sympatric polyploidization in plants. In common wheat (Triticum aestivum L.) and its triticeae relatives, UGs are not only instrumental in species evolution but may also serve as a powerful tool for modern crop improvement. This review synthesizes progress in understanding the cytological and genetic foundations of UG formation in plants, which primarily arises through meiotic restitution events. The achievements made so far in the exploitation of UGs are detailed, which suggest that appropriate manipulation of UGs has potentials in revolutionizing crop breeding, facilitating de novo synthesis of polyploids, enabling challenging wide hybridizations, and permitting direct introgression of valuable traits from wild relatives into cultivated backgrounds. To fully realize these potentials, there are still many biological and technical hurdles to overcome. We outline the major challenges and propose research directions for further basic and applied studies on UGs, which include elucidating the molecular mechanisms underpinning UG formation, raising the efficiency of UG induction, and integrating UG-based technology with crop genomics and advanced breeding pipelines. Breakthroughs in these areas of research will help to promote a new chapter of crop improvement through enhancing genetic diversities, cultivar innovation, and resilient production of crops in the face of worsening global climate change.

Grasping the dynamics between plants and herbivores, as well as the defenses triggered by insects, may hold the key to eco‐friendly pest management. Entomopathogenic nematodes (EPNs) have recently emerged as a promising biocontrol strategy, leading researchers to closely investigate how EPN‐infected cadavers influence plant defenses. A recent study 1 revealed notable alterations in herbivore performance and a boost in defense chemicals in maize plants treated with these infected remains. These cadavers trigger the release of volatile organic compounds from plants, which discourage the herbivorous insect Spodoptera frugiperda from feeding and laying eggs while simultaneously attracting parasitic wasps. This activation of herbivore resistance in plants treated with EPN‐infected cadavers is evident through increased levels of defense hormones, elevated enzyme activity, and the heightened expression of defense‐related genes. The research also highlighted that different EPN species cause varying effects on plant responses and herbivore behaviors, indicating a need for further investigation into the specific secondary chemicals involved. Overall, these findings enhance our understanding of complex interactions between organisms above and below the ground and point toward potential sustainable agricultural practices.

Polyploidization is a fundamental evolutionary process in plants, including bread wheat. In the present study, we performed a comprehensive genome-wide analysis of dynamic homoeologous gene divergence in Aikang58 (AK58), a modern elite polyploid wheat cultivar with a recently released reference genome, and in other wheat genomes, including landraces, synthetic wheat, and several breeding lines. Over 40% of transposable element (TE) families exhibit biased distribution across the three wheat subgenomes. Approximately 95.0% (113 421) of genes are co-located with TEs, and these variable TEs significantly contribute to homoeologous divergence. We found that about 80% of triad homoeologs are divergent due to differences in expression or sub-functionalization. In addition, subgenome divergence potentially promote polyploid wheat domestication and improvement by increasing favorable homoeoallele combinations. Our findings suggest that homoeolog divergence contributes to the adaptation, domestication, and improvement of hexaploid wheat. The contribution of subgenomic divergence to polyploid heterosis is also discussed. This study provides a valuable resource for the investigation of how TEs drive homoeologous divergence during wheat domestication and improvement.

Broad-spectrum resistance (BSR) is highly sought after for the effective management of crop diseases. However, genes suitable for developing BSR remain scarce. In this study, we demonstrate the development of BSR to wheat yellow rust (YR), powdery mildew (PM), and leaf rust (LR) diseases elicited by three biotrophic fungal pathogens using a newly defined module, namely, RFEL1-NPR3. RFEL1 is an active RING-finger E3 ubiquitin ligase identified in diploid and polyploid wheat species, which ubiquitinates and promotes the degradation of wheat NPR3 (TaNPR3), an important negative immune regulator conserved in higher plants, via the 26S proteasome system. Downregulation of TaNPR3 by either overexpressing RFEL1 or knocking out TaNPR3 confers strong resistance against four different YR races as well as the PM and LR diseases without adverse effects on wheat growth and yield traits. Notably, the enhanced disease resistance exhibited by RFEL1-overexpressing and TaNPR3-knockout lines is correlated with increased expression of defense related genes and elevated stability of NPR1, a pivotal positive regulator of plant immune signaling. Our findings underscore the importance of ubiquitination-dependent NPR3 degradation in plant immunity and advocate for the application of the RFEL1-NPR3 module in engineering BSR against biotrophic fungal pathogens in wheat and other crops.

The Glu-D1 locus of the Aegilops tauschii genome carries two high-molecular-weight glutenin genes, Dx and Dy, that are essential for viscoelastic properties of bread wheat dough, contributing to its success as a global staple crop. Here, we examined 48 Ae. tauschii high-quality genome assembles and identified a large dataset of Glu-D1, a locus that has remained recalcitrant to high-resolution analysis due to its genomic complexity. Phylogenetic analysis supported six major clades, slightly differing from the geography-based classification. Despite a short genomic distance, gene-based haplotype analysis detected possible ancestral recombination between Dx and Dy genes that were separated by distinctive repetitive sequences. Biochemically, glutenins of the same length can vary in isoelectric points, causing deviations in migration on traditional SDS-PAGE gels. Differential selection pressures were detected among clades and between Dx and Dy glutenin genes. Two clades, L2E-1 and L2W-2, with relatively lower coeliac motifs, were identified as the most probable ancestral contributors to bread wheat. Furthermore, key amino acids were identified as conceptually suitable for single-base editing to create novel elite alleles. Dissecting genomic diversity of the Glu-D1 loci deepens our understanding of the evolutionary trajectory of these long-studied seed storage proteins and offers new strategies for wheat grain-quality improvement.

Broad spectrum resistance genes are desirable in wheat breeding because they confer resistance against multiple pathogens. Kinase fusion proteins confer broad spectrum resistance in wheat. The resistance locus Pm4 encodes a kinase fusion protein that confers resistance to the fungal diseases powdery mildew and wheat blast.

Wheat leaf rust, caused by Puccinia triticina (Pt), threatens global wheat production, with yield losses further exacerbated by the pathogen's evolving virulence. Although Syg1/Pho81/Xpr1 (SPX) domain-containing proteins are known regulators of phosphate homeostasis, their involvement in plant-pathogen interactions remains largely unexplored. We demonstrated that TaSPX3, a wheat SPX family gene, is rapidly induced during early Pt infection and flg22 treatment. Genetic evidence indicates that TaSPX3 is a positive regulator of rust resistance, with knockdown lines showing increased susceptibility and overexpression lines exhibiting enhanced resistance. Using yeast two-hybrid screening, we identified TaDi19-1D, a zinc finger transcription factor, as a direct TaSPX3 interactor. TaDi19-1D functions as a negative immune regulator by suppressing the expression of pathogenesis-related (PR) genes (TaPR1, TaPR2, TaPR5) through direct promoter binding. TaSPX3 counteracts this repression by physically interacting with TaDi19-1D, thereby derepressing PR gene expression and boosting wheat resistance to Pt. Our findings revealed a novel TaSPX3-TaDi19 regulatory module that fine-tunes TaPRs expression, providing mechanistic insights into pattern-triggered immunity (PTI) and potential genetic targets for breeding durable broad-spectrum disease-resistant wheat varieties.