棉花茉莉酸羧基甲基转移酶基因克隆及其表达分析

Cloning and Expression Analysis of GhJMT Gene from Gossypium hirsutum

根据亚洲棉石系亚1号的转录组测序结果,克隆获得陆地棉品种"新陆早17号"的茉莉酸羧基甲基转移酶(jasmonic acid carboxyl methyltransferase,JMT)全长cDNA,命名为GhJMT(GenBank登录号KJ856913)。序列分析表明,GhJMT基因开放阅读框为1 116bp,编码371个氨基酸。保守结构域分析显示,该基因编码的蛋白具有甲基转移酶-7保守结构域。系统进化树分析显示,GhJMT与可可的茉莉酸甲基转移酶在同一分支,可能定位于细胞质,为不稳定亲水性蛋白。实时荧光定量PCR分析表明,2.5%PEG6000胁迫处理12h时,根中GhJMT基因的表达迅速上调并达到最大值,约为对照的2.6倍,在茎中GhJMT的表达量在9h达到最高,约为对照的2.3倍,而在叶中GhJMT表达量在3h达到最高,约为对照组的2.1倍,说明GhJMT基因表达受干旱胁迫的诱导。研究结果有助于阐明GhJMT基因表达与植物抗旱的相关性。

According to the transcriptome of Asian cotton Shixiya I（Gossypium arboretum）, a cDNA fragment was isolated from upland cotton cultivar ＇XLZ17＇ （Gossypium hirsutum）. The obtained cD- NA was named as jasmonic acid carboxyl methyltransferase of Gossypium hirsutum （GhJMT, Gen- Bank accession： KJ856913）. Sequence analysis indicated that GhJMT contains an open reading frame （ORF） of 1 116 bp, which encodes 371 amino acids. Conserved domain analysis showed that GhJMT has a conserved domain of methyltransferase-7. Phylogenetic tree analysis indicated that GhJMT was closer to the counterpart in Theobroma cacao, which was an unstable hydrophilic proteins sub-cellularly cytoplasm. Real time quantitative PCR results showed that the expression of GhJMT gene in roots after drought stress for 12 h was rapidly up-regulated and reached the highest, which was 2.6- fold of the control. While in stems the expression of GhJMT reached the highest level at 9 h and about 2.3-fold of the control, but at 3 h the expression of GhJMT gene in leaves reached the highest, which was 2.1-fold of the control. Base on the experimental results, the expression of GhJMT gene could be induced by drought stress. The results would help to clarify the correlation between GhJMT gene expression and drought resistance of plants.