水稻响应稻黄单胞菌稻生致病变种xopV缺失突变体侵染早期的转录组分析

Transcriptomic Analysis of Rice with Early Response to Xoc GX01AxopV Infection

细菌性条斑病是水稻主要的细菌性病害之一,由稻黄单胞菌稻生致病变种(Xanthomonas oryzae pv.oryzicola, Xoc)引起。病原菌Ⅲ型分泌系统(typeⅢsecretion system, T3SS)分泌的Ⅲ型效应物(T3SS effector, T3SE)对其致病力有重要的影响。本实验室前期发现广西Xoc菌株GX01的Ⅲ型效应物基因xopV缺失突变体菌株的致病力有明显的增加。为探索效应物XopV在水稻中的作用机制,本研究分别用缺失突变体Xoc GX01ΔxopV菌株和野生型菌株Xoc GX01压渗接种日本晴水稻叶片,对接种24 h后的日本晴水稻叶片进行转录组测序分析。测序分析结果显示,与野生型菌株Xoc GX01相比,缺失突变体Xoc GX01ΔxopV菌株侵染水稻叶片24 h后,在转录组水平从水稻中共鉴定出255个差异表达基因(differentially expressed genes, DEGs),其中表达上调的基因有66个,表达下调的基因有189个。DEGs中与植物抗性相关的基因包括编码4个转录因子(MYB, WRKY)、 4个类受体激酶(RLK)、 11个抗性相关蛋白和2个糖基转移酶的基因。此外,KEGG代谢途径富集分析发现DEGs参与苯丙烷类生物合成和植物激素信号转导等代谢途径。本研究重点从转录组水平分析了XopV在Xoc GX01与水稻互作中可能的作用机制,为XopV作用机制的深入研究奠定了良好的基础。

Rice bacterial leaf streak is one of the major bacterial diseases of rice and is caused by Xanthomonas oryzae pv.oryzicola(Xoc).The T3SS effector(T3SE)secreted by the type II secretion system(T3SS)of pathogenic bacteria have an important contribu-tion to its pathogenicity.Our previous study found that the pathogenicity of the T3SE xopV deletion mutant of Guangxi Xoc strain GXO1 was significantly increased.To explore the mechanism of the effector XopV in rice,we inoculated the leaves of Nipponbare with deletion mutant Xoc GX01AxopV strain and wild-type strain Xoc GX01,respectively,and performed transcriptome sequencing analysis of Nip-ponbare leaves 24 hours after inoculation.The results of sequencing analysis showed that compared with the wild-type strain Xoc CX01.a total of 255 differentially expressed genes(DEGs)were identified at the transcriptome level after the deletion mutant Xoc GX01AxopV strain infected rice leaves for 24 hours,of which 66 were up-regulated and 189 were down-regulated.Among the differentially expressed genes,4 transcription factors(MYB,WRKY),4 receptor-like kinases(RLK),1l resistance-related proteins and 2 glycosyltransferas-es coding genes were related to plant resistance.In addition,KECG metabolic pathway enrichment analysis found that DEGs were in-volved in metabolic pathways such as phenylpropane biosynthesis,plant hormone signal transduction.This study focused on analyzing the possible mechanism of XopV in the interaction between Xoc GXo1 and rice from the transcriptome level,and laid a good foundation for further research on the mechanism of XopV.