桃MPK3基因的克隆、表达及生物信息学分析

为探究MPK3响应GA信号调控休眠解除的分子机理,以中油四号油桃为试验材料,通过实时荧光定量PCR发现GA诱导下MAPKs家族基因在桃芽中有不同程度的表达,其中PpMPK3响应GA正调控表现最强烈。利用MEGA6.0、MEME、GSDS、DNAMAN 6.0等软件对桃PpMPK3基因进行生物信息学分析,结果表明,PpMPK3的cDNA全长1 113 bp,编码370个氨基酸,蛋白分子量约为42.6 kD,理论等电点为5.62,属于亲水性不稳定蛋白。预测PpMPK3蛋白发生磷酸化修饰的位点有45个,不存在糖基化位点。PpMPK3蛋白的二级结构中α-螺旋占41.35%,延伸链占10.54%,无规则卷曲为48.11%。进化树分析表明,PpMPK3氨基酸序列与甜樱桃亲缘关系最近,同源性为99.73%。通过亚细胞定位发现,PpMPK3定位于细胞核。RT-PCR结果表明,PpMPK3的表达模式与休眠解除过程相一致,推测PpMPK3能够响应GA信号,促进休眠解除。本研究结果为桃设施栽培的休眠调控提供了一定的理论依据。

Cloning,Expression and Bioinformatics Analysis of MPK3 in Peach

To explore the molecular mechanism of MPK3 response to GA signal regulation of dormancy release, the medium oil nectarine was used as the experimental material, real-time quantitative PCR showed that the MAPKs family gene was expressed in different degrees in peach buds under the induction of GA, and PpMPK3 responded strongly to the positive regulation of GA. Bioinformatics analysis of PpMPK3 gene was carried out using software such as MEGA6.0, MEME, GSDS and DNAMAN 6.0. The results showed that the full-length cDNA of PpMPK3 was 1 113 bp, encoding 370 amino acids, and the molecular weight of the predicted protein was about 42.6 kD. The electrical point is 5.62, which is a hydrophilic unstable protein. There are 45 sites for predicting phosphorylation of PpMPK3 protein, and no glycosylation site. It is predicted that the secondary structure of PpMPK3 protein is mainly composed of α-helix, random coil and extended chain, among which α-helix accounts for 41.35%, extended chain accounts for 10.54%, and irregular curl is 48.11%. Phylogenetic tree analysis showed that the amino acid sequence of PpMPK3 was closely homologous to sweet cherry, and the homology was 99.73%. PpMPK3 was localized to the nucleus by subcellular localization. RT-PCR results showed that the expression pattern of PpMPK3 was consistent with the dormancy release process. It is speculated that PpMPK3 can respond to GA signals and promote dormancy release. The results of this study provide a theoretical basis for the dormancy regulation of peach cultivation.