Wounding induces the rapid and transient activation of a specific MAP kinase pathway
Wounding induces the rapid and transient activation of a specific MAP kinase pathway
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DOI：
10.1105/tpc.9.1.75
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发表时间：
1997-01-01
期刊：
影响因子：
11.6
通讯作者：
Hirt, H
中科院分区：
文献类型：
--
作者：
Bogre, L;Ligterink, W;Hirt, H
植物的机械损伤诱导的反应不仅涉及愈合，而且还涉及对潜在病原体的防御。为了理解损伤的细胞内信号传导机制，我们研究了蛋白激酶的参与。使用特异性抗体，我们表明，受伤的苜蓿叶特异性诱导瞬时激活的p44（MMK 4）激酶，这属于有丝分裂原活化蛋白激酶家族。尽管MMK 4途径的活化是翻译后过程并且不被α-鹅膏蕈碱和放线菌酮阻断，但失活取决于蛋白质因子的从头转录和翻译。在伤口诱导的活化后，MMK 4途径经历25分钟的不应期，在此期间不可能再刺激，表明失活机制仅是瞬时活性的。创伤激活p44（MMK 4）激酶后，MMK 4基因的转录水平增加，表明MMK 4基因可能是MMK 4途径的直接靶点。与此相反，转录的创伤诱导的Msg 1基因，编码一个假定的蛋白酶抑制剂，检测到只有几个小时后，受伤，脱落酸，甲基茉莉酸，和电活动是已知的介导植物中的伤口信号。然而，这些因子都不能在没有创伤的情况下激活p44（MMK 4）激酶，这表明MMK 4途径独立于这些信号起作用。
Mechanical injury in plants induces responses that are involved not only in healing but also in defense against a potential pathogen, To understand the intracellular signaling mechanism of wounding, we have investigated the involvement of protein kinases. Using specific antibodies, we showed that wounding alfalfa leaves specifically induces the transient activation of the p44(MMK4) kinase, which belongs to the family of mitogen-activated protein kinases. Whereas activation of the MMK4 pathway is a post-translational process and was not blocked by alpha-amanitin and cycloheximide, inactivation depends on de novo transcription and translation of a protein factor(s), After wound-induced activation, the MMK4 pathway was subject to a refractory period of 25 min, during which time restimulation was not possible, indicating that the inactivation mechanism is only transiently active, After activation of the p44(MMK4) kinase by wounding, transcript levels of the MMK4 gene increased, suggesting that the MMK4 gene may be a direct target of the MMK4 pathway. In contrast, transcripts of the wound-inducible MsWIP gene, encoding a putative proteinase inhibitor, were detected only several hours after wounding, Abscisic acid, methyl jasmonic acid, and electrical activity are known to mediate wound signaling in plants. However, none of these factors was able to activate the p44(MMK4) kinase in the absence of wounding, suggesting that the MMK4 pathway acts independently of these signals.