江苏农业学报2025，Vol.41Issue(8)：1490-1498,9.DOI:10.3969/j.issn.1000-4440.2025.08.005
稻曲病病菌植物细胞壁降解酶活性测定及其与致病力的相关性分析
Determination of plant cell wall-degrading enzyme activity in Ustilagi-noidea virens and analysis of its correlation with pathogenicity
摘要
Abstract
Rice false smut,caused by Ustilaginoidea virens,severely impacts rice yield and grain quality,posing a significant threat to food security.Plant cell wall-degrading enzymes(PCWDEs)are critical virulence factors for patho-gens.To elucidate the role of PCWDEs in the infection of rice by U.virens,this study systematically identified 47 PCWDE-encoding genes based on the carbohydrate-active enzymes da-tabase(CAZy).Comparative genomic analysis revealed that the number of PCWDEs in U.virens was similar to that of biotrophic pathogens,but significantly lower than that of hemibiotrophic and saprophytic pathogens.Dynamic transcriptomic profiling showed that the relative expression levels of three key genes such as UV8b_01537,UV8b_03436,and UV8b_04918 were significantly up-regulated at 48 hours post-inoculation on rice.Their encoded proteins involved in the degradation of cellulose,hemicellulose,and starch,respectively.Enzymatic activity assays using p-nitrophenol chromogenic substrates indicated that PS culture medium,rice leaf tissue,and panicle tissue culture solutions induced the production of α-glucosidase,β-glucosidase,and β-xylanase in two highly virulent strains.These enzymes degrade starch,cellulose,and hemicellulose,respectively.Total enzyme activities exhibi-ted dynamic changes over time,peaking on the fourth day of culture under shaking conditions at 28℃and 180 r/min,and show-ing a negative correlation with pathogenicity.Notably,panicle tissue culture solutions induced significantly lower total enzyme ac-tivities compared to leaf tissue solutions.This study identified three PCWDE-encoding genes that were significantly upregulated during the early stages of infection,providing critical candidates for functional gene cloning.The findings also demonstrate that U.virens adapts to host tissue-specific microenvironments by differentially expressing PCWDE genes and dynamically regulating enzyme activities.These results offer insights into the environmental signaling mechanisms underlying the pathogen's specific in-fection of rice panicles and lay a foundation for further research.关键词
稻曲病/植物细胞壁降解酶/酶活性/水稻组织Key words
rice false smut/plant cell wall-degrading enzymes/enzyme activity/rice tissues分类
农业科技引用本文复制引用
高永煌,刘永锋,俞咪娜,于俊杰,曹慧娟,宋天巧,潘夏艳,王淑琛,王云鹏,靳丛..稻曲病病菌植物细胞壁降解酶活性测定及其与致病力的相关性分析[J].江苏农业学报,2025,41(8):1490-1498,9.基金项目
国家自然科学基金项目(32272512) （32272512）
海南省种业实验室项目(B23YQ1514/B23CQ15EP) （B23YQ1514/B23CQ15EP）
