陆地棉LTPG基因家族的全基因组鉴定及表达分析

Genome-wide identification and expression analysis of LTPG gene family in Gossypium hirsutum L.

【目的】从陆地棉全基因组范围内鉴定糖基磷脂酰肌醇锚定的脂质转运蛋白(glycosylphosphatidylinositol-anchored lipid transfer protein,LTPG)基因,为后续研究提供支撑。【方法】利用生物信息学方法从陆地棉TM-1基因组中筛选鉴定LTPG基因家族成员,并对其编码蛋白的理化性质、系统进化关系、基因复制、基因结构和启动子区的顺式作用元件等进行预测分析。利用转录组数据结合实时定量聚合酶链式反应(quantitative real-time polymerase chain reaction,qRT-PCR)分析LTPG基因在不同组织器官和非生物胁迫下的表达模式。在烟草叶片中采用瞬时转化法检测目标蛋白的亚细胞定位情况。【结果】在陆地棉基因组中共鉴定到95个GhLTPG基因,系统发育分析将这些GhLTPG蛋白聚为5类。片段复制是GhLTPG基因家族扩张的主要原因。Ka/Ks分析表明GhLTPG基因经历了强烈的纯化选择。转录组数据分析表明,部分GhLTPG基因响应低温、高温、盐和干旱胁迫。表达分析结果显示,Gh LTPG11/14/52/62基因响应低温、高温、盐及干旱胁迫,GhLTPG24/56响应低温、盐及干旱胁迫。亚细胞定位试验表明,GhLTPG24和GhLTPG62蛋白均定位于细胞膜。【结论】在陆地棉中鉴定到95个GhLTPG基因,部分GhLTPG基因响应低温、高温、盐和干旱等非生物胁迫,为深入解析GhLTPG基因功能奠定了基础。

[Objective]The glycosylphosphatidylinositol-anchored lipid transfer protein(LTPG)genes were identified from the whole genome of Gossypium hirsutum to provide support for subsequent research.[Method]Bioinformatics methods were used to screen and identify the LTPG gene family from the TM-1 genome,and the physicochemical properties of proteins,phylogenetic relationship,gene duplication,gene structure,and cis-acting elements in the promoter region were predicted and analyzed.Transcriptome data and real-time quantitative polymerase chain reaction(qRT-PCR)were used to analyze their expression pattern in different tissues and organs and under different abiotic stresses.The subcellular localization of the target proteins was identified by transient transformation in tobacco leaves.[Result]Ninety-five GhLTPG genes were identified in the G.hirsutum genome,which were clustered into 5 categories by phylogenetic tree analysis.Segment duplication is the main reason for the expansion of the GhLTPG gene family.Ka/Ks analysis indicated that GhLTPG underwent strong purification selection.Transcriptome data analysis showed that some GhLTPG responded to low temperature,high temperature,salt,or drought stress.The results of qRT-PCR analysis showed that GhLTPG11/14/52/62 responded to low temperature,high temperature, salt and drought stress, and GhLTPG24/56 responded to low temperature, salt, or drought stress. Subcellular localization experiments showed that both GhLTPG24 and GhLTPG62 were localized in the cell membrane. [Conclusion] Ninety-five GhLTPG genes were identified in the whole genome of G. hirsutum. Some GhLTPG genes responded to abiotic stresses such as low temperature, high temperature, salt and drought, which laid a foundation for in-depth analysis of the function of specific GhLTPG gene.