Department of Plant Pathology, University of California, Davis, CA 95616, USA.
Mol Plant. 2008 May;1(3):446-58. doi: 10.1093/mp/ssn024.
The rice Xa21 gene, which confers resistance to the bacterial pathogen Xanthomonas oryzae pv. oryzae (Xoo), encodes a receptor-like kinase. Few components involved in transducing the Xa21-mediated defense response have yet been identified. Here, we report that XA21 binds to a WRKY transcription factor, called OsWRKY62. The OsWRKY62 gene encodes two splice variants (OsWRKY62.1 and OsWRKY62.2). OsWRKY62.1:smGFP2 and OsWRKY62.2:smGFP2 fusion proteins partially localize to the nucleus. Transgenic plants overexpressing OsWRKY62.1 are compromised in basal defense and Xa21-mediated resistance to Xoo. Furthermore, overexpression of OsWRKY62.1 suppresses the activation of defense-related genes. These results imply that OsWRKY62 functions as a negative regulator of innate immunity in rice, and serves as a critical mediator of both basal and race-specific defense responses.
水稻 Xa21 基因赋予了对细菌性病原菌稻黄单胞菌 pv.oryzae（Xoo）的抗性，它编码一个受体样激酶。然而，参与转导 Xa21 介导的防御反应的几个成分尚未被鉴定。在这里，我们报告 XA21 与一个 WRKY 转录因子 OsWRKY62 结合。OsWRKY62 基因编码两个剪接变体（OsWRKY62.1 和 OsWRKY62.2）。OsWRKY62.1:smGFP2 和 OsWRKY62.2:smGFP2 融合蛋白部分定位于细胞核。过表达 OsWRKY62.1 的转基因植物在基础防御和 Xa21 介导的对 Xoo 的抗性方面受损。此外，过表达 OsWRKY62.1 抑制了与防御相关基因的激活。这些结果表明，OsWRKY62 在水稻中作为先天免疫的负调节剂发挥作用，并作为基础和特定品种防御反应的关键介质。
