Dash Manoranjan, Somvanshi Vishal Singh, Budhwar Roli, Godwin Jeffrey, Shukla Rohit N, Rao Uma
Division of Nematology, ICAR-Indian Agricultural Research Institute, New Delhi, 110012, India.
Bionivid Technology Private Limited, 209, 4th Cross, Kasturi Nagar, Bangalore, 560043, India.
Planta. 2021 Apr 17;253(5):108. doi: 10.1007/s00425-021-03625-0.
Resistance to rice root-knot nematode Meloidogyne graminicola in a mutant rice line is suggested to be conferred by higher expression of several genes putatively involved in damage-associated molecular pattern recognition, secondary metabolite biosynthesis including phytoalexins, and defence-related genes. Meloidogyne graminicola has emerged as the most destructive plant-parasitic nematode disease of rice (Oryza sativa L.). Genetic resistance to M. graminicola is one of the most effective methods for its management. A M. graminicola-resistant O. sativa ssp. indica mutant line-9 was previously identified through a forward genetic screen (Hatzade et al. Biologia 74:1197-1217, 2019). In the present study, we used RNA-Sequencing to investigate the molecular mechanisms conferring nematode resistance to the mutant line-9 compared to the susceptible parent JBT 36/14 at 24 h post-infection. A total of 674 transcripts were differentially expressed in line-9. Early regulation of genes putatively related to nematode damage-associated molecular pattern recognition (e.g., wall-associated receptor kinases), signalling [Nucleotide-binding, Leucine-Rich Repeat (NLRs)], pathogenesis-related (PR) genes (PR1, PR10a), defence-related genes (NB-ARC domain-containing genes), as well as a large number of genes involved in secondary metabolites including diterpenoid biosynthesis (CPS2, OsKSL4, OsKSL10, Oscyp71Z2, oryzalexin synthase, and momilactone A synthase) was observed in M. graminicola-resistant mutant line-9. It may be suggested that after the nematode juveniles penetrate the roots of line-9, early recognition of invading nematodes triggers plant immune responses mediated by phytoalexins, and other defence proteins such as PR proteins inhibit nematode growth and reproduction. Our study provides the first transcriptomic comparison of nematode-resistant and susceptible rice plants in the same genetic background and adds to the understanding of mechanisms underlying plant-nematode resistance in rice.
一个突变水稻品系对水稻根结线虫（Meloidogyne graminicola）的抗性被认为是由几个可能参与损伤相关分子模式识别、包括植保素在内的次生代谢物生物合成以及防御相关基因的更高表达所赋予的。水稻根结线虫已成为水稻（Oryza sativa L.）最具破坏性的植物寄生线虫病害。对水稻根结线虫的遗传抗性是其防治的最有效方法之一。一个抗水稻根结线虫的籼稻突变品系9先前是通过正向遗传筛选鉴定出来的（Hatzade等人，《Biologia》74:1197 - 1217，2019）。在本研究中，我们使用RNA测序来研究与感病亲本JBT 36/14相比，突变品系9在感染后24小时对线虫产生抗性的分子机制。品系9中共有674个转录本差异表达。在抗水稻根结线虫的突变品系9中观察到了与线虫损伤相关分子模式识别（如壁相关受体激酶）、信号传导【核苷酸结合、富含亮氨酸重复序列（NLRs）】、病程相关（PR）基因（PR1、PR10a）、防御相关基因（含NB - ARC结构域的基因）以及大量参与次生代谢物（包括二萜生物合成，如CPS2、OsKSL4、OsKSL10、Oscyp71Z2、稻瘟菌素合酶和茉莉内酯A合酶）的基因的早期调控。可以推测，线虫幼虫侵入品系9的根后，对入侵线虫的早期识别触发了由植保素介导的植物免疫反应，而其他防御蛋白如PR蛋白则抑制线虫的生长和繁殖。我们的研究首次对相同遗传背景下的抗线虫和感病水稻植株进行了转录组比较，并增进了对水稻抗线虫机制的理解。
