【摘要】 由革兰氏阴性菌黄单胞杆菌的致病变种(Xanthomonas oryzae pv.oryzicola, Xoc)引起的水稻细菌性条斑病(bacterial leaf streak, BLS),简称细条病,是国际上重要的检疫性病害之一。有效利用野生稻(Oryza rufipogon Griff.)抗细条病基因进行抗病品种培育可以从源头解决细条病防治问题。bls2是从广西普通野生稻中鉴定的一个对细条病具有广谱抗性的基因,但是其抗病机制尚不清楚。本研究通过代谢组学分析抗病近等基因系‘9311-bls2’及其轮回亲本‘9311’响应细条病菌侵染的抗性机制。结果发现,两份材料在接种细条病菌后48 h,上调的差异代谢物均明显多于下调的差异代谢物,表明水稻可能主要通过促进代谢物的合成来响应细条病菌的侵染。在‘9311’中上调的差异代谢物主要为萜类化合物、类固醇和类固醇衍生物、吲哚及其衍生物;而在‘9311-bls2’中上调的差异代谢物主要为萜类化合物、酚酸及其衍生物、类固醇和类固醇衍生物。此外, KEGG富集分析表明,‘9311’和‘9311-bls2’在细条病菌侵染后,差异代谢物共同显著富集于植物激素信号转导、二萜生物合成和色氨酸代谢途径。而α-亚麻酸代谢、多种植物次生代谢产物的生物合成,以及苯丙氨酸、酪氨酸和色氨酸的生物合成途径则是‘9311-bls2’特有的显著代谢通路。茉莉酸、赤霉素、肉桂酸、二氢人参二醇、邻氨基苯甲酸、对香豆酰胍丁胺等代谢物在‘9311-bls2’中含量显著上调,可能在抵御细条病菌侵染中起到了关键作用。本研究为揭示抗细条病基因bls2的抗性机制提供一定的参考。更多还原

【Abstract】 Bacterial leaf streak(BLS), caused by Xanthomonas oryzae pv. oryzicola(Xoc), is one of the internationally destructive quarantine diseases in rice. Utilizing BLS-resistant genes from common wild rice(Oryza rufipogon Griff.) to breed resistant varieties offers a fundamental solution for BLS control. bls2 is a gene identified from Guangxi common wild rice that exhibits broad-spectrum resistance to BLS. However, its disease resistance mechanism remains unclear. In this study, metabolomic analysis was conducted to investigate the molecular mechanism of BLS-resistant near isogenic line ’9311-bls2’ and its recurrent parent ’9311’ responding the infection of Xoc. The results revealed that there were more upregulated differential metabolites than downregulated ones in both materials at 48 h of post inoculation(hpi), indicating that rice may primarily respond to the infection of Xoc by promoting the synthesis of metabolites. In’9311’, the upregulated differential metabolites were mainly terpenoids, steroids and their derivatives, as well as indoles and their derivatives. In contrast, in ’9311-bls2’, the upregulated differential metabolites were primarily terpenoids, phenolic acids and their derivatives, steroids and their derivatives. Furthermore, KEGG enrichment analysis indicated that, after infection by Xoc, differential metabolites in both ’9311’ and ’9311-bls2’ were significantly co-enriched in pathways such as plant hormone signal transduction, diterpenoid biosynthesis, and tryptophan metabolism. Notably, α-linolenic acid metabolism, biosynthesis of various plant secondary metabolites, and biosynthesis of phenylalanine, tyrosine, and tryptophan were uniquely enriched in ’9311-bls2’. Key metabolites such as jasmonic acid, gibberellin, cinnamic acid, dihydroginsendiol, anthranilic acid, and p-coumaroyl agmatine were significantly upregulated in ’9311-bls2’, and they may have played crucial roles in the resistance response to Xoc infection. This study provides valuable insights into the resistance mechanisms of resistant gene bls2 against BLS.更多还原