植物类赖氨酸/组氨酸转运蛋白LHT基因家族的进化及在大豆中的功能研究

Evolutionary and Functional Analysis of Lysine/Histidine-like Transporter Genes in Glycine max (soybean)

利用9种具有全基因组数据的代表植物,通过生物信息学和分子生物学的研究手段,分析了被子植物LHT基因家族的进化机制,探讨了该基因家族在大豆中的功能分化。结果表明:(1)在选取的9个被子植物代表物种中,共含有114个LHT同源基因,大豆中含有25个,内含子数目1~9。(2)进化分析表明被子植物LHT可聚为7个亚家族Ⅰ—Ⅶ,其中Ⅱ的成员最多,Ⅲ为单子植物特有;编码的大豆氨基酸数量为56~543,相对分子量为6.3×103~57.1×103,理论等电点为6.03~9.51,均为跨膜蛋白。(3)大豆中GmaLHT表达模式分析表明,该基因家族的表达受到根瘤菌侵染的诱导,在根瘤侵染后部分成员在根和根瘤中特异性表达。大豆GmaLHT家族基因表达模式在不同亚家族的差异化结果表明,其在进化过程中受到选择的作用。(4)GmaLHT17基因超表达植株中该基因mRNA的表达水平为对照植株的13.6倍,且超表达植株的结瘤数目较对照植株有明显的增加。

Using 9 representative plants with whole-genome data,the evolutionary mechanism and functional differentiation of LHT gene family are analyzed in angiosperms,and the functions in soybean is also discussed through bioinformatics and molecular biology methods.The results show that a total of 114 LHT s are found in nine plant species,and 25 LHT s are found in soybean with the number of introns ranging from 1 to 9.Based on multiple sequence alignment and phylogenetic tree analysis,it is divided that the 114 LHT proteins intoⅠandⅦgroups,groupⅡhas the most members,and groupⅢis specific to the monocot plants.The number of encoded the soybean amino acids ranged from 56 to 543,the relatively molecular weight ranged from 6.3×103 to 57.1×103,and the theoretical pI ranged from 6.03 to 9.51,all of which are transmembrane proteins.The expression pattern analyses show that the expression of GmaLHT s is induced by rhizobium infection,and some members are specifically expressed in roots and nodules after rhizobium infection.The differential expression patterns of LHT genes in different evolutionary groups in soybean suggest that it maybe undergone selection in the process of evolution.The expression level of GmaLHT17 mRNA in overexpression transgenic plants is 13.6 times higher than that of the control plants,and the number of nodules in the overexpression transgenic plants is significantly higher than that in the control plants.