Contribution of salicylic acid glucosyltransferase, OsSGT1, to chemically induced disease resistance in rice plants
Contribution of salicylic acid glucosyltransferase, OsSGT1, to chemically induced disease resistance in rice plants
复制标题
DOI：
10.1111/j.1365-313x.2008.03697.x
复制
发表时间：
2009-02-01
期刊：
影响因子：
7.2
通讯作者：
Mitomi, Masaaki
中科院分区：
文献类型：
--
作者：
Umemura, Kenji;Satou, Junji;Mitomi, Masaaki
系统获得性抗性(SAR)是植物的一种自然病害反应，可以用化学方法诱导。水杨酸(SA)是调节双子叶植物SAR的关键内源信号分子。然而，SA在单子叶植物中的作用尚不清楚。在这项研究中，通过基于基因表达的微阵列检测，评估了农化保护剂化学物质丙苯唑的作用模式。对活性最高的丙苯唑反应基因的克隆和鉴定表明，该基因编码UDP-葡萄糖：SA葡萄糖转移酶(OsSGT1)，催化游离SA转化为SA O-β-葡萄糖苷(SAG)。我们发现，丙苯唑或2，6-二氯异烟酸处理后，水稻叶片组织中有SAG的积累。克隆了水稻品种Akitakomachi的OsSGT1基因，并对其在大肠杆菌中的表达产物进行了鉴定，结果表明异丙苯唑反应的OsSGT1参与了SAG的产生。此外，RNAi介导的OsSGT1基因沉默显著降低了丙苯唑对稻瘟病抗性的依赖发展，进一步支持了OsSGT1是化学诱导抗病发展的关键媒介的说法。OsSGT1基因可能通过诱导水稻植株SAG表达上调而参与SA信号转导机制。
Systemic acquired resistance (SAR), a natural disease response in plants, can be induced chemically. Salicylic acid (SA) acts as a key endogenous signaling molecule that mediates SAR in dicotyledonous plants. However, the role of SA in monocotyledonous plants has yet to be elucidated. In this study, the mode of action of the agrochemical protectant chemical probenazole was assessed by microarray-based determination of gene expression. Cloning and characterization of the most highly activated probenazole-responsive gene revealed that it encodes UDP-glucose:SA glucosyltransferase (OsSGT1), which catalyzes the conversion of free SA into SA O-beta-glucoside (SAG). We found that SAG accumulated in rice leaf tissue following treatment with probenazole or 2,6-dichloroisonicotinic acid. A putative OsSGT1 gene from the rice cultivar Akitakomachi was cloned and the gene product expressed in Escherichia coli was characterized, and the results suggested that probenazole-responsive OsSGT1 is involved in the production of SAG. Furthermore, RNAi-mediated silencing of the OsSGT1 gene significantly reduced the probenazole-dependent development of resistance against blast disease, further supporting the suggestion that OsSGT1 is a key mediator of development of chemically induced disease resistance. The OsSGT1 gene may contribute to the SA signaling mechanism by inducing up-regulation of SAG in rice plants.