A novel transcription factor UvCGBP1 regulates development and virulence of rice false smut fungus Ustilaginoidea virens

• Published in: Virulence 2021-12, Vol.12 (1), p.1563-1579
• Main Authors: Chen, Xiaoyang, Li, Pingping, Liu, Hao, Chen, Xiaolin, Huang, Junbin, Luo, Chaoxi, Li, Guotian, Hsiang, Tom, Collinge, David B., Zheng, Lu
• Format: Article
• Language: English
• Subjects: ChIP-seq; Fungal Proteins - genetics; Hypocreales - pathogenicity; MAPK pathway; Oryza - microbiology; Plant Diseases - microbiology; Research Paper; Transcription Factors - genetics; Ustilaginoidea virens; UvCGBP1; Virulence
• ISSN: 2150-5594; 2150-5608
• DOI: 10.1080/21505594.2021.1936768

Ustilaginoidea virens, causing rice false smut (RFS) is an economically important ascomycetous fungal pathogen distributed in rice-growing regions worldwide. Here, we identified a novel transcription factor UvCGBP1 ( C utinase G -box b inding p rotein) from this fungus, which is unique to ascomycetes. Deletion of UvCGBP1 affected development and virulence of U. virens. A total of 865 downstream target genes of UvCGBP1 was identified using ChIP-seq and the most significant KEGG enriched functional pathway was the MAPK signaling pathway. Approximately 36% of target genes contain the AGGGG (G-box) motif in their promoter. Among the targets, deletion of UvCGBP1 affected transcriptional and translational levels of UvPmk1 and UvSlt2, both of which were important in virulence. ChIP-qPCR, yeast one-hybrid and EMSA confirmed that UvCGBP1 can bind the promoter of UvPmk1 or UvSlt2. Overexpression of UvPmk1 in the ∆UvCGBP1-33 mutant restored partially its virulence and hyphae growth, indicating that UvCGBP1 could function via the MAPK pathway to regulate fungal virulence. Taken together, this study uncovered a novel regulatory mechanism of fungal virulence linking the MAPK pathway mediated by a G-box binding transcription factor, UvCGBP1.