Functional analysis of oxidative stress-activated mitogen-activated protein kinase cascade in plants
Functional analysis of oxidative stress-activated mitogen-activated protein kinase cascade in plants
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DOI：
10.1073/pnas.97.6.2940
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发表时间：
2000-03-14
影响因子：
11.1
通讯作者：
Sheen, J
中科院分区：
文献类型：
--
作者：
Kovtun, Y;Chiu, WL;Sheen, J
尽管认识到H2 O2作为一个中央信号分子在胁迫和创伤的反应，病原体防御，细胞周期和细胞死亡的调节，很少有人知道H2 O2信号是如何感知和转导在植物细胞。我们在这里报告，过氧化氢是一个有效的激活剂的有丝分裂原激活蛋白激酶（MAPKs）在拟南芥叶细胞。使用表位标签和ii原生质体瞬时表达试验，我们表明，过氧化氢可以激活一个特定的拟南芥丝裂原活化蛋白激酶，ANP 1，启动磷酸化级联反应，涉及两个应力MAPK，AtMPK 3和AtMPK 6。组成型活性ANP 1模拟H2 O2效应并启动MAPK级联反应，诱导特定的应激反应基因，但它阻断生长素（植物有丝分裂原和生长激素）的作用。后者的观察提供了氧化应激和生长素信号转导之间的分子联系。最后，我们表明，转基因烟草植物表达的组成型活性烟草ANP 1同源物，NPK 1，显示增强的耐受性，多种环境胁迫条件下，不激活先前描述的干旱，寒冷，脱落酸信号通路。因此，操纵氧化应激信号传导途径的关键调节因子，如ANP 1/NPK 1，提供了一种用于工程化多种应激耐受性的策略，这可能极大地有益于农业。
Despite the recognition of H2O2 as a central signaling molecule in stress and wounding responses, pathogen defense, and regulation of cell cycle and cell death, little is known about how the H2O2 signal is perceived and transduced in plant cells. We report here that H2O2 is a potent activator of mitogen-activated protein kinases (MAPKs) in Arabidopsis leaf cells. Using epitope tagging and ii protoplast transient expression assay, we show that H2O2 can activate a specific Arabidopsis mitogen-activated protein kinase kinase kinase, ANP1, which initiates a phosphorylation cascade involving two stress MAPKs, AtMPK3 and AtMPK6. Constitutively active ANP1 mimics the H2O2 effect and initiates the MAPK cascade that induces specific stress-responsive genes, but it blocks the action of auxin, a plant mitogen and growth hormone. The latter observation provides a molecular link between oxidative stress and auxin signal transduction. Finally, we show that transgenic tobacco plants that express a constitutively active tobacco ANP1 orthologue, NPK1, display enhanced tolerance to multiple environmental stress conditions without activating previously described drought, cold, and abscisic acid signaling pathways. Thus, manipulation of key regulators of an oxidative stress signaling pathway, such as ANP1/NPK1, provides a strategy for engineering multiple stress tolerance that may greatly benefit agriculture.