Rice WRKY45 plays a crucial role in benzothiadiazole-inducible blast resistance
Rice WRKY45 plays a crucial role in benzothiadiazole-inducible blast resistance
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DOI：
10.1105/tpc.106.046250
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发表时间：
2007-06-01
期刊：
影响因子：
11.6
通讯作者：
Takatsuji, Hiroshi
中科院分区：
文献类型：
--
作者：
Shimono, Masaki;Sugano, Shoji;Takatsuji, Hiroshi
苯并噻唑（BTH）是一种植物激活剂，通过激活水杨酸（SA）信号通路来保护植物免受疾病的侵害。通过微阵列筛选，我们发现BTH和sa诱导的WRKY转录因子（TF）基因在BTH处理后3小时内上调。其中一种基因WRKY45在水稻（Oryza sativa）中的过表达显著增强了对稻瘟病菌的抗性。RNA干扰介导的WRKY45敲低降低了BTH诱导的对blast病的抗性，表明它是BTH诱导的防御反应所必需的。在瞬时表达系统中，WRKY45通过w -box激活报告基因转录。上位分析表明，WRKY45独立于NH1（拟南芥NPR1的水稻同源物）作用于SA信号通路，这将WRKY45与已知的拟南芥WRKY TFs区分开来。两个防御相关基因，编码谷胱甘肽s -转移酶和细胞色素P450，被发现在WRKY45的下游受到调控，但不受NH1的调控，这与WRKY45和NH1依赖性通路的明显独立性一致。在WRKY45过表达的水稻植株中，防御基因的表达随生长条件的变化而变化，表明一些环境因素在WRKY45转录的下游起作用。我们提出了WRKY45在BTH诱导和SA介导的水稻防御信号中的作用，以及它在提高水稻抗病性方面的潜在应用，这是全球重要的食物资源。
Benzothiadiazole (BTH) is a so-called plant activator and protects plants from diseases by activating the salicylic acid ( SA) signaling pathway. By microarray screening, we identified BTH- and SA-inducible WRKY transcription factor (TF) genes that were upregulated within 3 h after BTH treatment. Overexpression of one of them, WRKY45, in rice ( Oryza sativa) markedly enhanced resistance to rice blast fungus. RNA interference-mediated knockdown of WRKY45 compromised BTH- inducible resistance to blast disease, indicating that it is essential for BTH- induced defense responses. In a transient expression system, WRKY45 activated reporter gene transcription through W-boxes. Epistasis analysis suggested that WRKY45 acts in the SA signaling pathway independently of NH1, a rice ortholog of Arabidopsis thaliana NPR1, which distinguishes WRKY45 from known Arabidopsis WRKY TFs. Two defense-related genes, encoding a glutathione S-transferase and a cytochrome P450, were found to be regulated downstream of WRKY45 but were not regulated by NH1, consistent with the apparent independence of the WRKY45- and NH1-dependent pathways. Defense gene expression in WRKY45-overexpressed rice plants varied with growth conditions, suggesting that some environmental factor(s) acts downstream of WRKY45 transcription. We propose a role for WRKY45 in BTH- induced and SA- mediated defense signaling in rice and its potential utility in improving disease resistance of rice, an importance food resource worldwide.