叶用莴苣LsMYB44基因的克隆及表达分析

Cloning and expression analysis of LsMYB44 gene in leaf lettuce

【目的】分析叶用莴苣MYB44基因的生物学功能,为研究光质调控叶用莴苣生长代谢提供理论依据。【方法】根据本课题组前期转录组测序结果,筛选出差异表达的基因MYB44,通过克隆技术获得MYB44基因的全长cDNA序列,利用生物信息软件对其进行分析,同时通过实时荧光定量PCR(qRT-PCR)技术分析MYB44基因在不同光质处理下的表达量差异。【结果】克隆得到的cDNA序列长度为807 bp,编码268个氨基酸,命名为LsMYB44。LsMYB44蛋白的相对分子量为29.341 kDa,等电点为8.37。平均亲水数-0.512,不稳定系数为60.19,属于不稳定蛋白。不存在跨膜区域,且不存在信号肽。结构域分析显示LsMYB44具有MYB保守结构域,启动子顺式原件预测表明LsMYB44与光响应、激素响应、逆境胁迫等相关。实时荧光定量PCR分析显示,LsMYB44在不同光质处理下有明显下调。【结论】LsMYB44可能通过响应不同光质处理,从而负调控叶用莴苣花色苷的合成。

[Objective] To analyze the biological function of MYB44 gene in lettuce and provide a theoretical basis for its study on the regulation of light quality on the growth and metabolism of lettuce. [Methods] According to the early transcriptome sequencing results of our research group, a differentially expressed gene MYB44 was selected. The full-length cDNA sequence of MYB44 gene was obtained by cloning technology. Then it was analyzed by bioinformatic softwares. Meanwhile, the expression patterns of MYB44 gene under different light quality treatments were analyzed by real-time quantitative PCR. [Results] A cDNA sequence of 807 bp was cloned, which encodes 268 amino acids, and was named LsMYB44. The molecular weight of LsMYB44 protein was 29.314 kDa and the isoelectric point was 8.37. The average hydrophilic number was-0.512 and the instability coefficient was 60.19,showing that it belonged to a unstable protein. There was no transmembrane region and no signal peptide. Domain analysis showed that LsMYB44 had a MYB conserved domain. Prediction of promoter regulatory elements showed that LsMYB44 was related to light response, hormone response, adversity stress, etc. Real time quantitative PCR analysis showed that LsMYB44 was significantly down regulated under different light quality treatments. [Conclusion] LsMYB44 may negatively affect the biosynthesis of anthocyanin in lettuce by responding to different light quality treatments.