Division of Plant Sciences, C. Bond Life Science Center, University of Missouri, Columbia, MO 65211, USA.
School of Agriculture and Biology/State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai 200240, P.R. China.
Plant Commun. 2020 Jun 20;1(4):100087. doi: 10.1016/j.xplc.2020.100087. eCollection 2020 Jul 13.
pathovar () uses transcription activator-like effectors (TALEs) to cause bacterial blight (BB) in rice. In turn, rice has evolved several mechanisms to resist BB by targeting TALEs. One mechanism involves the nucleotide-binding leucine-rich repeat (NLR) resistance gene and TALEs. Reciprocally, has evolved TALE variants, C-terminally truncated versions (interfering TALEs or iTALEs), to overcome resistance. However, it remains unknown to what extent the two co-adaptive mechanisms mediate -rice interactions. In this study, we cloned and characterized five additional allelic genes, , , , , and from a collection of rice accessions. Sequence analysis revealed that and from different rice cultivars are identical. These genes and their predicted proteins were found to be highly conserved, forming a group of alleles. The XA1 alleles could be distinguished by the number of C-terminal tandem repeats consisting of 93 amino acid residues and ranged from four in XA14 to seven in XA45(t). allelic genes were identified in the 3000 rice genomes surveyed. On the other hand, iTALEs could suppress the resistance mediated by allelic genes, and iTALE genes were prevalent (∼95%) in Asian, but not in African strains. Our findings demonstrate the prominence of a defense mechanism in which rice depends on alleles and a counteracting mechanism in which relies on iTALEs for BB.
路径变种 () 使用转录激活子样效应物 (TALEs) 在水稻中引起细菌性枯萎病 (BB)。反过来，水稻进化出了几种针对 TALEs 的抵抗 BB 的机制。一种机制涉及核苷酸结合亮氨酸重复 (NLR) 抗性基因 和 TALEs。反过来， 进化出了 TALE 变体，即 C 端截断版本（干扰 TALEs 或 iTALEs），以克服 抗性。然而，这两种协同适应机制在多大程度上介导了 -水稻相互作用仍然未知。在这项研究中，我们从一组水稻品系中克隆并表征了另外五个 等位基因 ，分别是 、 、 、 和 。序列分析表明，来自不同水稻品种的 和 是相同的。这些基因及其预测的蛋白质高度保守，形成了一组 等位基因。XA1 等位基因可以通过由 93 个氨基酸残基组成的 C 端串联重复的数量来区分，范围从 XA14 的四个到 XA45(t) 的七个。在调查的 3000 个水稻基因组中鉴定出了 等位基因。另一方面，iTALEs 可以抑制由 等位基因介导的抗性，并且 iTALE 基因在亚洲的 菌株中普遍存在（约 95%），但在非洲的 菌株中不存在。我们的发现表明，水稻依赖 等位基因的防御机制和 菌株依赖 iTALEs 抵抗 BB 的拮抗机制都很突出。
