Arthrinium phaeospermum can cause branch wilting of Bambusa pervariabilis × Dendrocalamopsis grandis, causing great economic losses and ecological damage. A. phaeospermum was sequenced in sterile deionized water (CK), rice tissue (T1) and B. pervariabilis × D. grandis (T2) fluid by RNA-Seq, and the function of Ctf1β 1 and Ctf1β 2 was verified by gene knockout. There were 424, 471 and 396 differentially expressed genes between the T2 and CK, T2 and T1, and CK and T1 groups, respectively. Thirty DEGs had verified the change in expression by fluorescent quantitative PCR. Twenty-nine DEGs were the same as the expression level in RNA-Seq. In addition, ΔApCtf1β 1 and ΔApCtf1β 2 showed weaker virulence by gene knockout, and the complementary strains Ctf1β 1 and Ctf1β 2 showed the same virulence as the wild-type strains. Relative growth inhibition of ΔApCtf1β 1 and ΔApCtf1β was significantly decreased by 21.4% and 19.2%, respectively, by adding H₂O₂ compared to the estimates from the wild-type strain and decreased by 25% and 19.4%, respectively, by adding Congo red. The disease index of B. pervariabilis × D. grandis infected by two mutants was significantly lower than that of wild type. This suggested that Ctf1β genes are required for the stress response and virulence of A. phaeospermum.

Phomopsis capsici (P. capsici) causes branch blight of walnuts, which leads to significant economic loss. The molecular mechanism behind the response of walnuts remains unknown. Paraffin sectioning and transcriptome and metabolome analyses were performed to explore the changes in tissue structure, gene expression, and metabolic processes in walnut after infection with P. capsici. We found that P. capsici caused serious damage to xylem vessels during the infestation of walnut branches, destroying the structure and function of the vessels and creating obstacles to the transport of nutrients and water to the branches. The transcriptome results showed that differentially expressed genes (DEGs) were mainly annotated in carbon metabolism and ribosomes. Further metabolome analyses verified the specific induction of carbohydrate and amino acid biosynthesis by P. capsici. Finally, association analysis was performed for DEGs and differentially expressed metabolites (DEMs), which focused on the synthesis and metabolic pathways of amino acids, carbon metabolism, and secondary metabolites and cofactors. Three significant metabolites were identified: succinic semialdehyde acid, fumaric acid, and phosphoenolpyruvic acid. In conclusion, this study provides data reference on the pathogenesis of walnut branch blight and direction for breeding walnut to enhance its disease resistance.

Zanthoxylum armatum, a significant forest plant in southwestern China, is crucial for preserving soil and water resources. However, the presence of root rot disease has led to plant death, impacting the pepper sector. Effective control measures for this disease are still lacking. Rhizosphere microorganisms play a vital role in plant health by inhibiting plant pathogens and inducing plant resistance. This research aimed to isolate and characterize the pathogen responsible for root rot disease in Z. armatum. Comparative analysis of fungal and bacterial communities in the rhizosphere soil of healthy and diseased plants revealed Fusarium solani as the pathogenic fungus causing root rot disease. Diseased plants had a higher occurrence of Fusarium spp., while disease-free plants had a higher abundance of ecologically beneficial microbial communities that could potentially serve as biocontrol agents. Three bacterial strains (Bacillus subtilis, Bacillus amyloliquefaciens, and Bacillus siamensis) were identified as effective biocontrol agents, inhibiting the growth of the pathogenic fungus F. solani both in vivo and in vitro. This study deepens our understanding of the rhizosphere soil microbial community differences between diseased and healthy Z. armatum, providing potential biocontrol bacteria to enhance plant resistance against root rot disease.