茉莉酸甲酯诱导西瓜ClTPS1基因的表达特性及其生物学信息分析

Sequence Analysis of Cl TPS1 Gene in Watermelon and Its Expression Characteristic after Treated with MeJA

TPS基因在海藻糖的积累过程中具有决定性作用,目前对TPS亚家族Ⅰ型基因研究比较多,而对TPS亚家族Ⅱ型基因研究较少。我们选取了西瓜Ⅱ型TPS亚家族基因中的一个TPS基因,命名为Cl TPS1,对该基因进行了生物信息学分析。并进一步以二倍体西瓜细胞为材料,利用q RT-PCR技术对Cl TPS1基因在茉莉酸甲酯诱导下的表达特性进行了研究。结果表明Cl TPS1基因的转录起始位点位于起始密码子上游1 332 bp处,启动子区域包含多个激素响应元件和逆境胁迫响应元件等;该基因编码的蛋白含有831个氨基酸,分子量为94 104.2 Da,理论等电点为5.57。该基因与拟南芥TPS7基因同源性最高。而蛋白结构分析进一步暗示了该基因可能兼备TPS活性和TPP活性。在茉莉酸甲酯施加了4 h后Cl TPS1基因的表达量达到最高,整体变化呈现出先上升后下降的趋势。以上结果表明Cl TPS1基因能迅速响应逆境胁迫,并通过促进海藻糖生物合成抵御逆境。本研究不仅为利用茉莉酸甲酯提高西瓜抗逆性提供了理论支持,而且为以后深入研究植物中Ⅱ型TPS亚家族基因奠定基础。

TPS gene has a decisive role of trehalose accumulation. However, at present, there are many reports on the typeⅠ TPS subfamily gene, but less is known on the typeⅡ TPS subfamily gene. One TPS gene which is named as Cl TPS1, belonging to type Ⅱ TPS subfamily in watermelon, was selected for bioinformatic analysis. And its expression characteristics which induced by Methyl Jasmonate(Me JA) were studied by q RT-PCR technique using diploid watermelon cells as materials. The results showed that the transcription start site of Cl TPS1 gene was located at 1 332 bp upstream from the start codon and the promoter region contains multiple hormone responsive element,stress response elements, etc. This gene encodes a protein containing 831 amino acids, its molecular weight is 94 104.2 Da and the theoretical isoelectric point is 5.57. The gene is the highest homology with TPS7 gene in Arabidopsis thaliana. Moreover, the protein structure analysis indicate the gene is with the both activities of TPS and TPP. The expression of Cl TPS1 gene was highest after 4 h and the whole change showed a trend of first increasing and then decreasing. This study illustrates that Cl TPS1 gene could response to the stress signal and protect plant against stress via promoting trebalose biosynthesis. This study not only provides a theoretical support to improving the stress resistance of watermelon by Me JA, but also lay the foundation for further research the typeⅡTPS subfamily gene in plant.