内源茉莉酸甲酯的积累改变了大豆叶片与根的发育

茉莉酸甲酯是一种调节植物形态发生、诱导防御相关基因的植物信号转导分子。为了解内源茉莉酸甲酯在植物发育中的作用,将编码茉莉酸甲基转移酶的NTR1基因与CaMV 35S启动子连接并导入大豆植株。PCR及Northern杂交结果表明,NTR1基因稳定整合在大豆基因组并得到过量表达。与野生型植株相比,转基因大豆叶片与根的形态发生了显著的变化。大部分转基因大豆叶片变得细长,初生根生长受到抑制而侧根的生长却受到促进。定量分析结果表明,转基因大豆植株叶片中茉莉酸甲酯的含量比对照高出 2～2.5 倍。这些结果表明,内源茉莉酸甲酯的积累参与了大豆形态发生的调控。

Increased Endogenous Methyl Jasmonate Altered Leaf and Root Development in Transgenic Soybean Plants

Methyl jasmonate (MeJA) is a plant-signaling molecule that regulates plant morphogenesis and expression of plant defense genes. To determine the role of the endogenous MeJA levels in the development of plants, transgenic soybean [Glycine max (L.) Merrill] plants harboring NTR1 gene encoding for jasmonic acid carboxyl methyltransferase (JMT) were produced. The activation of NTR1 gene expression resulted in the production of MeJA. Overexpression of the NTR1 cDNA under the regulation of cauliflower mosaic virus (CaMV) 35S promoter in the transgenic soybean plants was confirmed using Northern blot analysis. The significant differences in leaf and root growth patterns were observed between the transgenic plants and the wild-type plants. The leaves of the transgenic plants were slightly elongated in length but dramatically narrowed in width compared with the nontransformed wild-type plants. In addition, elongation of primary root was inhibited in the overexpressed transgenic soybean plantlets, whereas the development of lateral root was stimulated relative to the nontransformed plants. The leaves of the transgenic plants showed 2-2.5-fold higher levels of MeJA than the control plants. These results indicated that the increased endogenous levels of MeJA is involved in regulation of morphogenesis in soybean plants.