基于转录组探究PacC介导的苹果黑腐皮壳菌致病机制  

Exploring PacC Mediated Pathogenic Mechanism of Valsa mali Based on Transcriptome

作　　者：祝山 王一波 李建宇 肖映竹 徐亮胜[1] 黄丽丽[1] ZHU Shan;WANG Yi-Bo;LI Jian-Yu;XIAO Ying-Zhu;XU Liang-Sheng;HUANG Li-Li(College of Plant Protection,Northwest A&F University,State Key Laboratory of Crop Stress Biology for Arid Areas,Yangling 712100,China)

机构地区：[1]西北农林科技大学植物保护学院/旱区作物逆境生物学国家重点实验室,杨凌712100

出　　处：《农业生物技术学报》2020年第12期2130-2140,共11页Journal of Agricultural Biotechnology

基　　金：国家自然科学基金(31772115)。

摘　　要：由苹果黑腐皮壳菌(Valsa mali)引起的苹果树(Malus pumila)腐烂病严重制约中国苹果产业的发展,全面解析黑腐皮壳菌的致病分子机制为该病害的有效防控提供重要理论依据。pH响应转录因子PacC在苹果黑腐皮壳菌侵染致病过程中起重要作用。为了揭示其转录调控机制,利用RNA-seq技术对苹果黑腐皮壳菌野生型菌株03-8和PacC基因敲除突变体ΔVmPacC在苹果枝条上的基因表达谱进行分析。结果显示苹果黑腐皮壳菌在前期侵染和后期侵染过程中分别有238和449个差异表达基因(differentially expressed genes,DEGs)。GO富集分析表明,DEGs主要参与碳水化合物代谢、氧化还原、跨膜运输、多糖代谢生物过程。KEGG富集分析表明,DEGs集中在淀粉和蔗糖代谢、氰基氨基酸代谢、戊糖和葡萄糖醛酸转换通路途径,这些途径上的差异基因多与植物细胞壁多糖(plant cell wall polysaccharide,PCWP)降解有关。将与PCWP降解相关基因的氨基酸序列提交到病原寄主互作(Pathogen Host Interactions,PHI)数据库比对,筛选出推定的果胶裂解酶A基因、果胶裂解酶B基因、假象蛋白基因VM1G08430三个潜在的致病关键基因。本研究挑选了6个DEGs进行qRT-PCR验证,结果表明6个基因的mRNA表达谱与RNAseq结果一致。综合分析表明,转录因子PacC通过调控PCWP降解基因的表达在苹果黑腐皮壳菌侵染致病过程中发挥功能。该研究揭示了PacC在苹果黑腐皮壳菌侵染致病过程中的转录调控机制,为该病原菌致病机制的阐明提供了理论基础。Apple tree canker caused by Valsa mali seriously restricts the development of apple industry in China.It is of great theoretical significance for the effective prevention and control of apple tree canker to comprehensively analyze the pathogenic molecular mechanism of V.mali.The pH-responsive transcription factor PacC play an important role in the infection and pathogenic process of V.mali.In order to reveal PacC transcriptional regulation mechanism,the gene expression profiles of V.mali wild-type 03-8 and the PacC deletion mutantΔVmPacC on branches were analyzed by RNA-seq assays.The results showed that there were238 and 449 differentially expressed genes(DEGs)during pre-infection and post-infection of V.mali.GO enrichment analysis showed that biological processes of DEGs were mainly involved in carbohydrate metabolic processes,oxidation-reduction process,transmembrane transport process and polysaccharide metabolic processes.KEGG functional enrichment analysis showed that the pathways of DEGs were mainly involved in starch and sucrose metabolism,cyanoamino acid metabolism,pentose and glucuronate interconversions,these DEGs involved in three pathways were mainly related to plant cell wall polysaccharide(PCWP)degradation.The amino acid sequences of DEGs involved PCWP degradation were submitted to Pathogen Host Interactions(PHI)-base blast,that obtained 3 potential pathogenic related genes including putative pectate lyase A gene,pectin lyase B gene,hypothetical protein gene VM1 G08430.In this study,six DEGs were selected for qRT-PCR verification,and the results showed that the mRNA expression patterns of the 6 genes were consistent with the results of RNA-seq assays.The comprehensive analysis showed that transcription factor PacC functions in the infection and pathogenic process by regulating the expression of PCWP degradation genes.The study revealed PacC transcriptional regulation mechanism in the infection and pathogenic process of V.mali,and it would lay a theoretical foundation a theoretical basis for explain

关 键 词：苹果黑腐皮壳菌 转录因子PacC 植物细胞壁多糖降解 

分 类 号：S432.44[农业科学—植物病理学]