Project description:In order to explore the role of LaeA in secondary metabolite biosynthetic gene clusters’ regulation, toxin production, and virulence of Valsa mali, TMT-based proteomic analysis of wildtype, LaeA deletion mutant and overexpression mutant were performed. Totally, 4,299 proteins (FDR < 0.01) were identified by searching against the Valsa mali protein sequence database.
Project description:MicroRNAs (miRNAs) play important roles by regulating the expression of target genes in plant and animal. However, little known about mechanism of fungal miRNA-like RNAs (milRNAs) regulating target gene restricts their functional exploration. In this study, multiple omics were used to identify the milRNAs and their target genes in a phytopathogenic fungus Valsa mali. Many candidate pathogenic factors were found to be regulated by milRNA-directed cleavage way. Absence or downregulated expression of Vm-milRNAs promote expression of candidate pathogenic factors during V. mali infection. Vm-milR16 is a significantly downregulated milRNA during V. mali infection, resulting in significantly upregulated expression of three target genes: VmSNF1, VmDODA, and VmHy1. Overexpression of Vm-milR16 significantly reduces the pathogenicity of V. mali. And all the three target genes of Vm-milR16 are required for the full pathogenicity of V. mali. Further analysis revealed that VmSNF1 regulates the pathogenicity by affecting the expression of pectinase genes during V. mali infection. And all the three target genes are essential for oxidative stress response during V. mali-host interaction. Vm-milRNAs may help V. mali to intelligently use limited resources and adaptively regulate pathogenicity by enhancing expression of pathogenic factors and fitness during infection.
Project description:Dicer proteins are mainly responsible for generating small RNAs (sRNAs). In previous study, two DCL proteins in Valsa mali, the pathogenic fungus of apple tree Valsa canker, were found to be associated with the pathogenicity and generation of sRNAs. In this study, we constructed two milRNA libraries using the the wild-type 03-8 (MVm) and Vm-DCL2 deletion mutant (MD2) strains and the differential expression of miRNA-like RNAs (milRNAs) were analyzed based on the deep-sequencing of the wild-type and Vm-DCL2 mutant, respectively. In total, by comparing the expression difference of milRNAs between MVm and MD2, it was found that 33 milRNAs were not detected in MD2, 28 milRNAs were both detected in MVm and MD2. By statistical analysis, one and 17 milRNAs showed up-regulated and down-regulated expression in MD2 compared with MVm, respectively (p<0.05). Importantly, 10 milRNAs were not detected in MD2, and identified to be DCL2 dependent milRNAs. We also identified the target genes of these milRNAs using degradome sequencing technology and found they were associated with protein phosphatase, isocitrate dehydrogenase, phosphoglycerate mutase, etc. The study will lay a foundation for the comprehensive analysis of pathogenic mechanisms of V. mali, and enrich cognition of the generation and function of fungal sRNA.