Dammann C, Rojo E, Sánchez-Serrano J J
Centro Nacional de Biotecnología CSIC, Madrid, Spain.
Plant J. 1997 Apr;11(4):773-82. doi: 10.1046/j.1365-313x.1997.11040773.x.
Mechanical damage to leaf tissue causes an increase in abscisic acid (ABA) which in turn activates the biosynthesis of jasmonic acid (JA). The resulting higher endogenous JA levels subsequently activate the expression of wound-inducible genes. This study shows that JA induces the expression of different sets of genes in roots and leaves of potato plants. When roots of intact plants were treated with JA, high levels of proteinase inhibitor II (pin2), cathepsin D inhibitor, leucine aminopeptidase and threonine deaminase mRNAs accumulated in the systemic leaves. However, in the treated roots, very low, if any, expression of these genes could be detected. In contrast, a novel, root-specific pin2 homologue accumulated in the JA-treated root tissue which could not be detected in leaves, either systemic or those directly treated with JA. Application of okadaic acid and staurosporine revealed that a protein phosphorylation step is involved in the regulation of this differential response. In leaves, a protein phosphatase is required for the JA-induced expression of pin2 and the other genes analysed. This phosphatase activity is not necessary for the JA-induced expression of a pin2 homologue in roots, suggesting the existence of different transduction pathways for the JA signal in these organs. The requirement of a protein phosphatase activity for JA-mediated gene induction has enabled identification of a JA-independent pathway for ABA induction of pin2 and the other wound-inducible genes. This alternative pathway involves a protein kinase, and appears to be selective for wound-inducible genes. Our data suggest the presence of a complex, organ-specific transduction network for regulating the effects of the plant hormones ABA and JA on gene expression upon wounding.
叶片组织的机械损伤会导致脱落酸（ABA）增加，进而激活茉莉酸（JA）的生物合成。由此产生的更高内源性JA水平随后会激活创伤诱导基因的表达。本研究表明，JA在马铃薯植株的根和叶中诱导不同组基因的表达。当完整植株的根用JA处理时，蛋白酶抑制剂II（pin2）、组织蛋白酶D抑制剂、亮氨酸氨肽酶和苏氨酸脱氨酶的高水平mRNA在系统叶中积累。然而，在处理过的根中，这些基因的表达（如果有的话）非常低。相反，一种新的、根特异性的pin2同源物在JA处理的根组织中积累，在系统叶或直接用JA处理的叶中均未检测到。应用冈田酸和星形孢菌素表明，蛋白质磷酸化步骤参与了这种差异反应的调节。在叶片中，pin2和其他分析基因的JA诱导表达需要一种蛋白质磷酸酶。这种磷酸酶活性对于根中pin2同源物的JA诱导表达不是必需的，这表明在这些器官中JA信号存在不同的转导途径。JA介导的基因诱导对蛋白质磷酸酶活性的需求使得能够鉴定出ABA诱导pin2和其他创伤诱导基因的JA非依赖性途径。这种替代途径涉及一种蛋白激酶，并且似乎对创伤诱导基因具有选择性。我们的数据表明存在一个复杂的、器官特异性的转导网络，用于调节植物激素ABA和JA对创伤时基因表达的影响。
