Ghosh Srayan, Kanwar Poonam, Jha Gopaljee
Plant Microbe Interactions Laboratory, National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, 110067, India.
Curr Genet. 2018 Jun;64(3):729-740. doi: 10.1007/s00294-017-0791-7. Epub 2017 Dec 1.
Sheath blight disease is one of the predominant diseases of rice and it is caused by the necrotrophic fungal pathogen Rhizoctonia solani. The mechanistic insight about its widespread success as a broad host range pathogen is limited. In this study, we endeavor to identify pathogenicity determinants of R. solani during infection process in rice. Through RNAseq analysis, we identified a total of 65 and 232 R. solani (strain BRS1) genes to be commonly upregulated in three different rice genotypes (PB1, Tetep, and TP309) at establishment and necrotrophic phase, respectively. The induction of genes encoding extracellular protease, ABC transporter, and transcription factors were notable during establishment phase. While during necrotrophic phase, several CAZymes, sugar transporters, cellular metabolism, and protein degradation-related genes were prominently induced. We have also identified few putative secreted effector encoding genes that were upregulated during pathogenesis. The qPCR analysis further validated the phase-specific expression dynamics of some selected putative effectors and pathogenicity-associated genes. Overall, the present study reports identification of key genes and processes that might be crucial for R. solani pathogenesis. The ability to effectively damage host cell wall and survive in hostile plant environment by managing oxidative stress, cytotoxic compounds, etc. is being proposed to be important for pathogenesis of R. solani in rice. The functional characterization of these genes would provide key insights about this important pathosystem and facilitate development of strategies to control this devastating disease.
纹枯病是水稻的主要病害之一，由坏死营养型真菌病原菌立枯丝核菌引起。关于其作为一种广泛寄主范围病原菌广泛成功的机制见解有限。在本研究中，我们致力于鉴定立枯丝核菌在水稻感染过程中的致病性决定因素。通过RNAseq分析，我们分别在定殖期和坏死营养期，在三种不同水稻基因型（PB1、Tetep和TP309）中总共鉴定出65个和232个立枯丝核菌（菌株BRS1）基因上调。在定殖期，编码细胞外蛋白酶、ABC转运蛋白和转录因子的基因的诱导显著。而在坏死营养期，几种碳水化合物活性酶、糖转运蛋白、细胞代谢和蛋白质降解相关基因被显著诱导。我们还鉴定出一些在致病过程中上调的假定分泌效应子编码基因。qPCR分析进一步验证了一些选定的假定效应子和致病性相关基因的阶段特异性表达动态。总体而言，本研究报告了对可能对立枯丝核菌致病至关重要的关键基因和过程的鉴定。通过应对氧化应激、细胞毒性化合物等，有效破坏宿主细胞壁并在恶劣植物环境中存活的能力被认为对立枯丝核菌在水稻中的致病作用很重要。这些基因的功能表征将为这个重要的病理系统提供关键见解，并促进控制这种毁灭性疾病的策略的开发。
