Plant-positive single-stranded RNA viruses induce vesicles that are crucial for viral infection, replication and spread. However, the mechanisms underlying the vesicle biogenesis induced by negative single-stranded RNA viruses remain largely unknown. Here, a negative single-stranded RNA virus, tomato spotted wilt orthotospovirus (TSWV) which is a representative member of genus Orthotospovirus in the Tospoviridae family, was used as a model to investigate the mechanisms involving the interaction between the viral and the host plant proteins in vesicle formation and function. We found that the nonstructural protein (NSm) of TSWV, could induce endoplasmic reticulum (ER)-derived pathological vesicle biogenesis. In addition, NSm might hijack the host immunity proteins, NtPOX1 (a peroxidase) and pathogenesis-related protein NtPR-4A, to form a potential tetrameric protein complex with Sar1 (a small GTPase), which was crucial for NSm-induced vesicle biogenesis. The results also showed that these ER-derived pathological vesicles provided sites for TSWV replication. These findings provide novel and robust insights for understanding the infection processes and mechanisms of plant-negative single-stranded RNA viruses.

Through long-term natural selection, a co-evolutionary relationship has formed between plants and pests. However, pathogens and pests can also undermine plant resistance by releasing certain substances such as effectors. Helicoverpa armigera R-like protein 1 (HARP1), an effector in oral secretions, is capable of interacting with JASMONATE-ZIM DOMAIN (JAZ) protein. This interaction inhibits the degradation of JAZ and prevents the activation of jasmonic acid (JA) signalling in response to biotic stress. Nevertheless, the mechanism by which HARP1 interacts with JAZ to suppress JA signalling remains elusive. In this study, we first confirm that the ZIM domain within JAZ is sufficient for the HARP1-JAZ interaction. To gain mechanistic insight, we determined the crystal structure of HARP1 and utilised AlphaFold2 to predict its binding mode with JAZ3. The structure analysis reveals that HARP1 is a β-sandwich fold composed of seven strands, which directly binds to JAZ homo- or hetero-dimers. This binding prevents the degradation of the JAZ repressor, consequently ensuring the repressed JA signalling pathway in the plant. Our structural and functional studies provide new insights into the JA signalling transcriptional repression mechanism by effectors released by pests that suppress JA signalling.

Rhizosphere metabolites play a pivotal role in plant-soil-microbe interactions, yet the absence of standardised sampling method presents challenges for data comparability and a unified understanding of rhizochemistry dynamics. In this study, the rhizosphere metabolites of spring wheat (Triticum aestivum L.) were systematically evaluated using three commonly used sampling methods - rhizosphere soil extraction, hydroponic collection, and in situsampling. We assessed the differences in metabolite abundance, diversity, composition, and metabolic pathways among the three methods. The results revealed that rhizosphere soil extraction method is simple and repeatable, but it tends to underestimate the rare metabolic features compared to the other two methods. The hydroponic collection method offered a more comprehensive rhizochemical profile, however, it may not reflect the actual soil environment in which plants grow. The in situ method mostly captured the rhizochemical dynamics under natural conditions but was technically complex and less reproducible. Pathway enrichment of differential metabolic features showed a distinct pattern, with hydroponic emphasising plant-centric primary metabolism, and rhizosphere soil extraction and in situ methods reflecting pathways more associated with environmental interaction and ecological adaptation. Overall, our results highlight that the sampling methods significantly influences the abundance and composition of the detected rhizochemical profile, thus the rhizosphere metabolites sampling methods should be considered according to the experimental objectives of future research.

Little is known about regulatory mechanisms that crop plants use to respond to combinations of abiotic and biotic stress. We analysed four barley genotypes under simultaneous Fusarium culmorum infection and drought stress by phenotyping for Fusarium Head Blight (FHB) disease, drought stress responses, hormone profiling and transcriptome analysis. FHB severity was host genotype-dependent, with moderately resistant cultivars Avalon and Barke showing increased FHB under drought, while drought did not further increase FHB severity in highly susceptible Morex and Palmella Blue. Transcriptome analysis revealed largely additive effects of single stresses, with drought-dominated regulation with increasing drought severity. Co-expression analysis connected abscisic acid and auxin to gene expression modules functionally enriched with stress-specific physiological responses. Stress-response genes, uniformly expressed across genotypes, were linked to pathogen defence, detoxification and drought adaptation, whereas a cluster of hundreds of moderately Fusarium-responsive genes was limited in up-regulation under combined stress, possibly explaining enhanced FHB severity under drought. A multiple linear regression model accurately predicted combined stress expression from single stress responses, demonstrating that gene regulation under combined drought and Fusarium stress is largely driven by additive effects of individual stresses.

Salinity stress disrupts rhizosphere homoeostasis and inhibits root development. Although PGPR are known to alleviate such stress, critical knowledge gaps remain regarding the specific mechanisms by which they enhance tolerance under moderate to high salinity, particularly within the wheat rhizosphere -root interface. Here, we show that Bacillus cereus T146, isolated from saline-alkali soil, enhances wheat salt tolerance through two integrated mechanisms. Metagenomic and culturomic analyses further revealed that T146 enriches IAA-producing Pseudomonas in the rhizosphere, and co-inoculation experiments demonstrated that these recruited bacteria contribute synergistically to salt tolerance. On the host side, transcriptomic and cell biological analyses demonstrated that T146 reactivates salt-suppressed auxin pathways. Specifically, inoculation upregulates key regulators of lateral root development (PLT3, PLT7, GLV6) and increases PIN1, PIN2, and PIN3 abundance, leading to elevated auxin accumulation as indicated by DR5::GFP signals. Importantly, silencing TaPIN1 largely compromised T146-induced tolerance and transcriptional reprogramming, demonstrating a functional interplay between microbiome modulation and host hormonal regulation. These results reveal that T146 synergistically promotes salinity resilience by coordinating rhizosphere microbiome remodelling with auxin-mediated root development, offering a mechanistic framework for microbiome-based strategies to improve crop stress tolerance.

Apple is an economically important crop worldwide, but its production is constrained by soil salinization. Excess salt impairs growth through ion toxicity, osmotic stress, and oxidative damage, ultimately compromising fruit quality and yield. Breeding salt-tolerant varieties is therefore a key strategy for sustaining production in saline environments. This study showed that a salt response transcription factor, MdWRKY75, enhances apple salt tolerance by regulating the sodium-potassium ion balance. Under salt stress, the Na+ content and Na+/K+ ratio in the roots and leaves of the MdWRKY75-overexpressing lines were significantly reduced compared with the wild type (WT). Moreover, the expression of genes responsible for salt ion transport was significantly upregulated. The RNA interference (RNAi) lines displayed the opposite phenotype. Further analysis revealed that MdWRKY75 binds to the MdSOS3 promoter and positively regulates its expression. The roots of plants overexpressing MdSOS3 lines showed salt tolerance and could rescue the salt-sensitive phenotype of MdWRKY75-Ri3. Yeast one-hybrid revealed a gene in the ethylene signalling pathway, MdERF1B, as the upstream transcription factor of MdWRKY75. Electrophoretic mobility shift assay (EMSA), dual-luciferase, and β-glucuronidase (GUS) assays confirmed that MdERF1B activates the expression of MdWRKY75. Overexpressing MdERF1B in both WT and MdWRKY75-Ri3 backgrounds reduced the Na+ and Na+/K+ ratios in plants and improved salt tolerance. Additionally, exogenous application of 1-aminocyclopropane-1-carboxylic acid (ACC) enhanced apple salt tolerance by activating MdERF1B. Therefore, this study demonstrated that an ethylene-mediated MdERF1B-MdWRKY75-MdSOS3 module enhances apple salt tolerance by regulating the sodium-potassium ion balance.

Summary statement β‐caryophyllene (BCP) plays diverse roles in plants, particularly in resistance induction and plant‐plant communication. This study reports the underlying mechanism: BCP competes with NINJA and IAA1/IAA10 for TOPLESS binding, thereby relieving the repression of JA and auxin signalling pathways.

Climate change-driven heat and drought stresses during reproductive stages significantly threaten wheat productivity. To investigate the genetic and physiological basis of combined heat-drought (HD) tolerance, we evaluated 345 wheat genotypes under three environments of HD stresses, non-stress glasshouse conditions and a late-sowing field trial. HD stresses caused significant reductions in chlorophyll content, flag leaf area, biomass, seed-setting rate and grain weight-related traits. Notably, HD-tolerant lines maintained higher grain weight, grain number and chlorophyll retention, with less than half the reductions observed in sensitive genotypes. A genome-wide association study using a 40K single-nucleotide polymorphism (SNP) array identified 124 candidate SNPs (cSNPs) associated with 51 traits across three environments with 78 cSNPs associated with HD tolerance. In total, 24 cSNP blocks exhibited pleiotropic associations with multiple traits under those three environments. Tight genomic co-localisations were detected between chlorophyll content (SPAD or CCM200 values), flag leaf width, seed-setting rate and grain yield components (thousand grain weight, grain number per spike), with superior haplotypes identified, supporting their utility in selections. Stay-green traits appeared to contribute significantly to yield stability under HD stresses. Those results provide valuable genomic and physiological insights into wheat HD tolerance for future targeted wheat breeding.