Jasmonate is essential for insect defense Arabidopsis
Jasmonate is essential for insect defense Arabidopsis
复制标题
DOI：
10.1073/pnas.94.10.5473
复制
发表时间：
1997-05-13
影响因子：
11.1
通讯作者：
Browse, J
中科院分区：
文献类型：
--
作者：
McConn, M;Creelman, RA;Browse, J
众所周知，允许植物防御咀嚼类昆虫的信号通路非常复杂，为了研究茉莉酸在拟南芥伤口信号传导中的作用，并测试昆虫防御是否存在平行或冗余通路，我们研究了一种缺乏茉莉酸前体亚麻酸的突变体（fad3-2fad7-2fad8），突变体植物含有可忽略不计的茉莉酸水平，并表现出极高的死亡率（约 80%）来自常见腐食性真菌蚊蚋、凤仙花迟缓虫（双翅目：蚱科）幼虫的攻击，尽管邻近的野生型植物基本上未受影响。外源茉莉酸甲酯的施用显着保护了突变体植物并将死亡率降低至约12%。这些实验精确地定义了茉莉酸在植物与昆虫相互作用中诱导生物有效防御所必需的作用。三个伤口反应基因的转录物被证明不是由突变植物的伤口诱导的，但相同的转录物可以通过应用茉莉酸甲酯来诱导。相比之下，对编码谷胱甘肽S-转移酶的基因的转录物水平的测量表明，该基因的伤口诱导与茉莉酸合成无关。这些结果表明，该突变体将成为测试候选防御基因实际有效性的良好遗传模型。
The signaling pathways that allow plants to mount defenses against chewing insects are known to be complex, To investigate the role of jasmonate in wound signaling in Arabidopsis and to test whether parallel or redundant pathways exist for insect defense, we have studied a mutant (fad3-2fad7-2fad8) that is deficient in the jasmonate precursor linolenic acid, Mutant plants contained negligible levels of jasmonate and showed extremely high mortality (approximate to 80%) from attack by larvae of a common saprophagous fungal gnat, Bradysia impatiens (Diptera: Sciaridae), even though neighboring wild-type plants were largely unaffected. Application of exogenous methyl jasmonate substantially protected the mutant plants and reduced mortality to approximate to 12%. These experiments precisely define the role of jasmonate as being essential for the induction of biologically effective defense in this plant-insect interaction. The transcripts of three wound-responsive genes were shown not to be induced by wounding of mutant plants but the same transcripts could be induced by application of methyl jasmonate, By contrast, measurements of transcript levels for a gene encoding glutathione S-transferase demonstrated that wound induction of this gene is independent of jasmonate synthesis. These results indicate that the mutant will be a good genetic model for testing the practical effectiveness of candidate defense genes.