A fungal-responsive MAPK cascade regulates phytoalexin biosynthesis in Arabidopsis
A fungal-responsive MAPK cascade regulates phytoalexin biosynthesis in Arabidopsis
复制标题
拟南芥中真菌响应性 MAPK 级联调节植物抗毒素生物合成
DOI：
10.1073/pnas.0711301105
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发表时间：
2008-04-08
影响因子：
11.1
通讯作者：
Zhang, Shuqun
中科院分区：
文献类型：
--
作者：
Ren, Dongtao;Liu, Yidong;Zhang, Shuqun
植物对病原体的识别导致 MPK3 和 MPK6 的快速激活，这两种拟南芥丝裂原激活蛋白激酶 (MAPI(s)) 及其在其他物种中的直系同源物。在这里，我们报道了拟南芥中主要植物抗毒素 Camalexin 的合成受到 MPK3/MPK6 级联的调节。通过表达活性上游 MAPK 激酶 (MAPKK) 或 MAPKK 激酶来激活 MPK3/MPK6 (MAPKKK) 在没有病原体攻击的情况下足以诱导 camalexin 的合成，先于 MPK3/MPK6 激活，并在 mpk3 和 mpk6 突变体中受到损害。遗传分析将 MPK3/MPK6 级联置于 PHYTOALEXIN DEFICIENT 2 (PAD2) 和 PAD3 的上游，但在 PAD1 和 PAD4 诱导后独立或下游。 MPK3/MPK6 激活之前，色氨酸 (Trp) 生物合成途径、Trp 转化为吲哚-3-乙醛肟（IAOx，初级代谢和次级代谢之间的分支点）以及 IAOx 下游的 camalexin 生物合成途径中编码酶的多个基因快速且协调地上调。这些结果表明，MPK3/MPK6 级联通过转录调节 camalexin 的合成。病原体感染后的生物合成基因。
Plant recognition of pathogens leads to rapid activation of MPK3 and MPK6, two Arabidopsis mitogen-activated protein kinases (MAPI(s), and their orthologs in other species. Here, we report that synthesis of camalexin, the major phytoalexin in Arabidopsis, is regulated by the MPK3/MPK6 cascade. Activation of MPK3/MPK6 by expression of active upstream MAPK kinase (MAPKK) or MAPKK kinase (MAPKKK) was sufficient to induce camalexin synthesis in the absence of pathogen attack. Induction of camalexin by Botrytis cinerea was preceded by MPK3/MPK6 activation, and compromised in mpk3 and mpk6 mutants. Genetic analysis placed the MPK3/ MPK6 cascade upstream of PHYTOALEXIN DEFICIENT 2 (PAD2) and PAD3, but independent or downstream of PAD1 and PAD4. Camalexin induction after MPK3/MPK6 activation was preceded by rapid and coordinated up-regulation of multiple genes encoding enzymes in the tryptophan (Trp) biosynthetic pathway, in the conversion of Trp to indole-3-acetaldoxime (IAOx, a branch point between primary and secondary metabolism), and in the camalexin biosynthetic pathway downstream of IAOx. These results indicate that the MPK3/MPK6 cascade regulates camalexin synthesis through transcriptional regulation of the biosynthetic genes after pathogen infection.