The mitogen-activated protein kinase cascade MKK3-MPK6 is an important part of the jasmonate signal transduction pathway in Arabidopsis
The mitogen-activated protein kinase cascade MKK3-MPK6 is an important part of the jasmonate signal transduction pathway in Arabidopsis
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DOI：
10.1105/tpc.106.046581
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发表时间：
2007-03-01
期刊：
影响因子：
11.6
通讯作者：
Shinozaki, Kazuo
中科院分区：
文献类型：
--
作者：
Takahashi, Fuminori;Yoshida, Riichiro;Shinozaki, Kazuo
植物激素茉莉酸（JA）在植物对环境胁迫的反应和发育过程中起着关键作用。虽然ATMYC 2/JASMONATE-INSENSITIVE 1（JIN 1）是JA诱导基因表达的主要正调控因子，并且在拟南芥JA依赖性发育过程中是必需的，但ATMYC 2/JIN 1表达控制的分子机制仍不清楚。在这里，我们确定了一个丝裂原活化蛋白激酶（MAPK）级联，MAPK激酶3（MKK 3）-MAPK 6（MPK 6），这是激活JA在拟南芥。我们还表明，JA负控制ATMYC 2/JIN 1的表达，基于定量RT-PCR和遗传分析，使用功能获得和功能丧失突变体的MKK 3-MPK 6级联。这些结果表明，该激酶单位在JA-dependent ATMYC 2/JIN 1表达的负调控中起关键作用。JA的正性和负性调节都可用于微调ATMYC 2/JIN 1表达以控制JA信号传导。此外，JA调节的根生长抑制受到MKK 3-MPK 6级联中的突变的影响，这表明JA信号传导中的重要作用。我们提供了一个模型，解释MPK 6如何可以转换三个不同的信号-JA，病原菌，和冷/盐胁迫-成三套不同的反应在拟南芥。
The plant hormone jasmonic acid (JA) plays a key role in the environmental stress responses and developmental processes of plants. Although ATMYC2/JASMONATE-INSENSITIVE1 (JIN1) is a major positive regulator of JA-inducible gene expression and essential for JA-dependent developmental processes in Arabidopsis thaliana, molecular mechanisms underlying the control of ATMYC2/JIN1 expression remain largely unknown. Here, we identify a mitogen-activated protein kinase (MAPK) cascade, MAPK KINASE 3 (MKK3)-MAPK 6 (MPK6), which is activated by JA in Arabidopsis. We also show that JA negatively controls ATMYC2/JIN1 expression, based on quantitative RT-PCR and genetic analyses using gain-of-function and loss-of-function mutants of the MKK3-MPK6 cascade. These results indicate that this kinase unit plays a key role in JA-dependent negative regulation of ATMYC2/JIN1 expression. Both positive and negative regulation by JA may be used to fine-tune ATMYC2/JIN1 expression to control JA signaling. Moreover, JA-regulated root growth inhibition is affected by mutations in the MKK3-MPK6 cascade, which indicates important roles in JA signaling. We provide a model explaining how MPK6 can convert three distinct signals-JA, pathogen, and cold/salt stress-into three different sets of responses in Arabidopsis.