Chen Hui, Jones A Daniel, Howe Gregg A
Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, 48824, USA.
FEBS Lett. 2006 May 15;580(11):2540-6. doi: 10.1016/j.febslet.2006.03.070. Epub 2006 Apr 7.
The phytohormone jasmonic acid (JA) regulates the synthesis of secondary metabolites in a wide range of plant species. Here, we show that exogenous methyl-JA (MeJA) elicits massive accumulation of caffeoylputrescine (CP) in tomato leaves. A mutant (jai1) that is defective in jasmonate perception failed to accumulate CP in flowers and MeJA-treated leaves. Conversely, a transgenic tomato line (called 35S::PS) that exhibits constitutive JA signaling accumulated high levels of leaf CP in the absence of jasmonate treatment. RNA blot analysis showed that genes encoding enzymes in the phenylpropanoid and polyamine pathways for CP biosynthesis are upregulated in MeJA-treated wild-type plants and in untreated 35S::PS plants. These results indicate that CP accumulation in tomato is tightly controlled by the jasmonate signaling pathway, and provide proof-of-concept that the production of some plant secondary metabolites can be enhanced by transgenic manipulation of endogenous JA levels.
植物激素茉莉酸（JA）可调节多种植物物种中次生代谢产物的合成。在此，我们表明外源茉莉酸甲酯（MeJA）可引发番茄叶片中咖啡酰腐胺（CP）的大量积累。一个在茉莉酸感知方面存在缺陷的突变体（jai1）在花朵和经MeJA处理的叶片中无法积累CP。相反，一个表现出组成型JA信号传导的转基因番茄品系（称为35S::PS）在未进行茉莉酸处理的情况下积累了高水平的叶片CP。RNA印迹分析表明，在经MeJA处理的野生型植物和未经处理的35S::PS植物中，编码参与CP生物合成的苯丙烷类和多胺途径中酶的基因被上调。这些结果表明，番茄中CP的积累受到茉莉酸信号传导途径的严格控制，并提供了概念验证，即通过对内源JA水平进行转基因操作可以增强某些植物次生代谢产物的产生。
