Disclosure of the Molecular Mechanism of Wheat Leaf Spot Disease Caused by Bipolaris sorokiniana through Comparative Transcriptome and Metabolomics Analysis

摘要

Wheat yield is greatly reduced because of the occurrence of leaf spot diseases. is the main pathogenic fungus in leaf spot disease. In this study, from wheat leaf (W- ) showed much stronger pathogenicity toward wheat than endophytic from (P- ). The transcriptomes and metabolomics of the two strains and transcriptomes of -infected wheat leaves were comparatively analyzed. In addition, the expression levels of unigenes related to pathogenicity, toxicity, and cell wall degradation were predicted and validated by quantitative reverse transcription polymerase chain reaction (qRT-PCR) analysis. Results indicated that pathogenicity-related genes, especially the gene encoding loss-of-pathogenicity B (LopB) protein, cell wall-degrading enzymes (particularly glycosyl hydrolase-related genes), and killer and Ptr necrosis toxin-producing related unigenes in the W- played important roles in the pathogenicity of W- toward wheat. The down-regulation of cell wall protein, photosystem peptide, and rubisco protein suggested impairment of the phytosynthetic system and cell wall of -infected wheat. The up-regulation of hydrolase inhibitor, NAC (including NAM, ATAF1 and CUC2) transcriptional factor, and peroxidase in infected wheat tissues suggests their important roles in the defensive response of wheat to W- . This is the first report providing a comparison of the transcriptome and metabolome between the pathogenic and endophytic strains, thus providing a molecular clue for the pathogenic mechanism of W- toward wheat and wheat’s defensive response mechanism to W- Our study could offer molecular clues for controlling the hazard of leaf spot and root rot diseases in wheat, thus improving wheat yield in the future.