Regulation of ACS protein stability by cytokinin and brassinosteroid.
Regulation of ACS protein stability by cytokinin and brassinosteroid.
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DOI：
10.1111/j.1365-313x.2008.03711.x
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发表时间：
2009-02
期刊：
影响因子：
--
通讯作者：
Kieber JJ
中科院分区：
文献类型：
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作者：
Hansen M;Chae HS;Kieber JJ
植物生物学中的一个主要问题是植物激素途径如何相互作用。在这里，我们探讨了细胞分裂素和油菜素类固醇影响乙烯生物合成的机制。乙烯的生物合成受多种内源性和外源性信号的调节，包括其他植物激素的水平。细胞分裂素通过增加ACC脱氢酶亚类的稳定性起作用，ACC脱氢酶催化乙烯生物合成中的一般限速步骤。细胞分裂素对乙烯的诱导需要经典的细胞分裂素双组分反应途径，包括组氨酸激酶、组氨酸磷酸转移蛋白和反应调节剂。细胞分裂素诱导的myc-ACS 5稳定化发生迅速（<60分钟），与该双组分信号传导途径的主要输出一致。我们研究了另一种植物激素，油菜素类固醇，提高乙烯生物合成黄化苗的机制。与细胞分裂素类似，油菜素类固醇通过增加ACS 5蛋白的稳定性在转录后发挥作用，并且其对ACS 5的作用与细胞分裂素的作用是相加的。这些数据表明，ACS是由植物激素通过调节输入，可能一起行动，以不断调整乙烯生物合成在各种组织中，并在各种环境条件下进行调节。
A major question in plant biology is how phytohormone pathways interact. Here, we explore the mechanism by which cytokinins and brassinosteroids affect ethylene biosynthesis. Ethylene biosynthesis is regulated in response to a wide variety of endogenous and exogenous signals, including the levels of other phytohormones. Cytokinins act by increasing the stability of a subset of ACC synthases, which catalyze the generally rate-limiting step in ethylene biosynthesis. The induction of ethylene by cytokinin requires the canonical cytokinin two-component response pathway, including histidine kinases, histidine phosphotransfer proteins and response regulators. The cytokinin-induced myc–ACS5 stabilization occurs rapidly (<60 min), consistent with a primary output of this two-component signaling pathway. We examined the mechanism by which another phytohormone, brassinosteroid, elevates ethylene biosynthesis in etiolated seedlings. Similar to cytokinin, brassinosteroid acts post-transcriptionally by increasing the stability of ACS5 protein, and its effects on ACS5 were additive with those of cytokinin. These data suggest that ACS is regulated by phytohormones through regulatory inputs that probably act together to continuously adjust ethylene biosynthesis in various tissues and in response to various environmental conditions.