WRKYs, a large family of transcription factors, are involved in plant response to biotic and abiotic stresses, but the role of them in tomato resistance to Oidium neolycopersici is still unclear. In this study, we evaluate the role of WRKYs in powdery mildew-resistant wild tomato (Solanum habrochaites) LA1777 defense against O. neolycopersici strain lz (On-lz) using a combination of omics, classical plant pathology- and cell biology-based approaches. A total of 27 WRKYs, belonging to group I, II, and III, were identified as differentially expressed genes in LA1777 against On-lz. It was found that expression of ShWRKY41 was increased after Pseudomonas syringae pv. tomato (Pst) DC3000, On-lz and Botrytiscinerea B05 inoculation or ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC) treatment. GUS staining of ShWRKY41 promoter indicated that the expression of ShWRKY41 could be induced by SA and ethylene. Furthermore, ShWRKY41 gene silencing reduced the resistance to On-lz infection by decreasing the generation of H₂O₂ and HR in LA1777 seedlings. Overall, our research suggests that ShWRKY41 plays a positive role in defense activation and host resistance to O. neolycopersici in wild tomato (S. habrochaites) LA1777.

Tomato powdery mildew, caused by Oidium neolycopersici, is a fungal disease that results in severe yield loss in infected plants. Herein, we describe the function of a class of proteins, soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs), which play a role in vesicle transport during defense signaling. To date, there have been no reports describing the function of tomato SNAREs during resistance signaling to powdery mildew. Using a combination of classical plant pathology-, genetics-, and cell biology-based approaches, we evaluate the role of ShNPSN11 in resistance to the powdery mildew pathogen O. neolycopersici. Quantitative RT-PCR analysis of tomato SNAREs revealed that ShNPSN11 mRNA accumulation in disease-resistant varieties was significantly increased following pathogen, compared with susceptible varieties, suggesting a role during induced defense signaling. Using in planta subcellular localization, we demonstrate that ShNPSN11 was primarily localized at the plasma membrane, consistent with the localization of SNARE proteins and their role in defense signaling and trafficking. Silencing of ShNPSN11 resulted in increased susceptibility to O. neolycopersici, with pathogen-induced levels of H₂O₂ and cell death elicitation in ShNPSN11-silenced lines showing a marked reduction. Transient expression of ShNPSN11 did not result in the induction of a hypersensitive cell death response or suppress cell death induced by BAX. Taken together, these data demonstrate that ShNPSNl11 plays an important role in defense activation and host resistance to O. neolycopersici in tomato LA1777.

Watermelon Fusarium wilt, caused by Fusarium oxysporum f. sp. niveum (FON), is one of the most important diseases, and has become a major limiting factor to watermelon production worldwide. Previous research has found that the improved biocontrol agent, F1-35, had a high control efficiency to watermelon Fusarium wilt. In this study, the control efficiency of F1-35 to watermelon Fusarium wilt was firstly tested, and the control efficiency was 61.7%. Then, we investigated the mode of action of F1-35 in controlling watermelon Fusarium wilt. Using a pairing assay, we found that F1-35 did not inhibit the normal growth of FON. To know more about the interaction between F1-35 and watermelon root, the protein expressions of roots after 12, 24, and 48 h post-inoculation were examined. A total of 1109 differentially expressed proteins were obtained. KEGG analysis found that the most differentially expressed proteins occurred in alpha-linolenic acid metabolism, cysteine and methionine metabolism, plant–pathogen interaction, and the MAPK signaling pathway to the plant. A further analysis of differentially expressed proteins showed that F1-35 triggered the jasmonic acid and ethylene pathways in watermelon. To validate our results, the qRT-PCR was used to analyze the gene expression levels of PAL, LOX1, and CTR1. The gene expression results showed that those genes, which were positive correlated with the JA pathway, were up-expressed, including PAL and LOX1, and the negative associated gene, CTR1, was down-expressed. In conclusion, the improved biocontrol agent, F1-35, improves the resistance of watermelons to FON by triggering the JA and ET pathways.

Carbon catabolite repression (CCR) is a common transcriptional regulatory mechanism that microorganisms use to efficiently utilize carbon nutrients, which is critical for the fitness of microorganisms and for pathogenic species to cause infection. Here, we characterized two CCR genes, VdCreA and VdCreC, in Verticillium dahliae that cause cotton Verticillium wilt disease. The VdCreA and VdCreC knockout mutants displayed slow growth with decreased conidiation and microsclerotium production and reduced virulence to cotton, suggesting that VdCreA and VdCreC are involved in growth and pathogenicity in V. dahliae. We further generated 36 highly reliable and stable ΔVdCreA and ΔVdCreC libraries to comprehensively explore the dynamic expression of genes and metabolites when grown under different carbon sources and CCR conditions. Based on the weighted gene co-expression network analysis (WGCNA) and correlation networks, VdCreA is co-expressed with a multitude of downregulated genes. These gene networks span multiple functional pathways, among which seven genes, including PYCR (pyrroline-5-carboxylate reductase), are potential target genes of VdCreA. Different carbon source conditions triggered entirely distinct gene regulatory networks, yet they exhibited similar changes in metabolic pathways. Six genes, including 6-phosphogluconolactonase and 2-ODGH (2-oxoglutarate dehydrogenase E1), may serve as hub genes in this process. Both VdCreA and VdCreC could comprehensively influence the expression of plant cell wall-degrading enzyme (PCWDE) genes, suggesting that they have a role in pathogenicity in V. dahliae. The integrated expression profiles of the genes and metabolites involved in the glycolysis/gluconeogenesis and pentose phosphate pathways showed that the two major sugar metabolism-related pathways were completely changed, and GADP (glyceraldehyde-3-phosphate) may be a pivotal factor for CCR under different carbon sources. All these results provide a more comprehensive perspective for further analyzing the role of Cre in CCR.

As critical regulatory elements in plant signaling transduction, 14-3-3 proteins orchestrate defense responses against biotic and abiotic stresses. This study investigates the functional role of TaGF14a in wheat’s immune response to Puccinia striiformis f. sp. tritici (Pst), providing novel genetic insights for stripe rust resistance breeding. Phylogenetic analysis revealed a close evolutionary relationship between TaGF14a and rice OsGF14a. Subcellular localization studies demonstrated that the protein was located in the in the nucleus, cytoplasm, and plasma membrane. Pathogen challenge experiments showed significant induction of TaGF14a expression following Pst inoculation. Virus-induced gene silencing (VIGS) technology was used to silence TaGF14a, which resulted in expanded necrotic lesions and compromised fungal containment during incompatible interactions. Concurrently, we observed downregulation of pathogenesis-related genes (TaPR1, TaPR3) and altered expression patterns in reactive oxygen species (ROS) metabolism genes (TaCAT, TaSOD). Protein interaction assays identified novel associations between TaGF14a and key defense components: xylanase inhibitor and E3 ubiquitin ligase RGLG2, suggesting coordinated regulation of cell wall reinforcement and proteasomal degradation pathways. Furthermore, TaGF14a exhibited dual stress responsiveness, showing 3.3-fold induction under methyl jasmonate treatment and 3-fold increase under cold stress (4 °C). This comprehensive analysis advances our understanding of 14-3-3 proteins in cereal-pathogen interactions and provides molecular targets for durable disease resistance strategies.

Cytospora chrysosperma is a common opportunistically parasitic fungus that mainly infects forest trees, severely restricting the development of the fruit and forest industry. Surfactin is a secondary metabolite produced by Bacillus species and exhibits antifungal activity; Although the core antifungal mechanism of surfactin against plant pathogens has been extensively studied, our study found that surfactin can target the tricarboxylic acid cycle of C. chrysosperma. This study aimed to investigate the potential mechanism underlying the inhibitory effect of surfactin on C. chrysosperma. The results showed that surfactin had a significant inhibitory effect on C. chrysosperma, with a half-maximal effective concentration of 0.787 ± 0.045 mg/mL and a minimum inhibitory concentration of 2 mg/mL. Morphological observations revealed that surfactin significantly disrupted the morphology and ultrastructure of C. chrysosperma hyphae. FDA/PI staining indicated that surfactin affected the cell membrane integrity of C. chrysosperma, while DCFH-DA fluorescent staining and antioxidant enzyme activity assays demonstrated the accumulation of reactive oxygen species in hyphal cells following surfactin treatment. Additionally, the reduction in adenosine triphosphate content, as well as the decreased activities of ATPase and succinate dehydrogenase, suggested that energy production might be inhibited. Finally, MDC staining showed the occurrence of autophagosomes in C. chrysosperma hyphae after surfactin treatment, which may lead to hyphal death. Transcriptome analysis revealed that surfactin impaired the normal biosynthesis of the C. chrysosperma cell membrane and interfered with the tricarboxylic acid cycle by binding to citrate synthase, resulting in intracellular energy metabolism disorders. This study provides new insights into the potential mechanism by which surfactin inhibits hyphal growth of C. chrysosperma.