烟草根系在青枯病菌侵染早期的蛋白组分析

Proteomic Analysis of Tobacco Roots at the Early Stage of Infection by Ralstonia solanacearum

烟草青枯病是一种由茄科雷尔氏菌(Ralstonia solanacearum)引起的毁灭性土传病害。为研究烟草根系在青枯菌侵染早期的抗性机理,本研究以抗青枯病品种D101为材料,对接种青枯菌3 h后的烟苗根系进行了蛋白组学分析。结果显示,与未接种的对照比较,青枯菌侵染早期的烟草根系中存在相当比例的差异表达蛋白,但蛋白表达水平的变化幅度总体上不高。在P值小于0.05和变化倍数大于1.2的标准下,筛选到63个差异表达蛋白。对这些蛋白进行基因本体(gene ontology,GO)和KEGG(Kyoto encyclopedia of genes and genomes)路径分析发现,烟草根系对青枯菌侵染的早期抗性主要涉及具有杀菌作用的次生代谢物(如木脂素)的合成,能够杀菌和诱导系统抗性的亚磷酸盐的合成,以及活性氧毒性物质(如过氧化氢)的消除方面的生物学过程和路径。本研究结果为深入研究烟草及其它茄科植物抗青枯病的分子机制提供了有价值的线索,也可为烟草青枯病抗性分子育种提供参考。

Bacterial wilt(BW)is a destructive soil-borne disease of tobacco caused by Ralstonia solanacearum(Rs).To study the mechanism of tobacco root resistance at the early stage of Rs infection,the BW-resistant variety D101 was used as material to analyze the proteome of seedling roots after inoculation with Rs for 3 h.The results showed that there was quite a proportion of differentially expressed proteins in tobacco seedling roots at the early stage of Rs infection in comparison with the non-inoculated control,but the degree of protein expression change was not large overall.Using the criteria of P-value 0.05 and fold change 1.2,a total of 63 differentially expressed proteins were identified.Gene ontology(GO)and KEGG pathway analyses based on these proteins suggested that the tobacco root resistance at the early stage of Rs infection mainly involves the biological processes or pathways of synthesis of germicidal secondary metabolites(e.g.lignan),synthesis of phosphinate that can inhibit pathogen and induce systemic resistance,and elimination of toxic reactive oxygen species(e.g.hydrogen peroxide).The results of this study provide valuable clues for deep research of the molecular mechanism of BW resistance in tobacco and other solanaceous plants,and also provide reference for molecular breeding of BW resistance in tobacco.