玉米AAP基因密码子偏性与进化分析

Codon bias and evolution analysis of maize AAP gene

氨基酸透性酶(AAP)通过参与植物体内氨基酸吸收和转运,从而改变植物生长发育。研究其密码子偏好性,对AAP基因异源表达、功能验证及完善其遗传转化体系具有指导意义。使用Codon W、EMBOSS、Origin 2021以及SPSS等程序软件,对25个物种的AAP基因密码子进行聚类、中性、ENC以及PR2绘图分析,选择玉米AAP最佳异源表达受体及遗传转化受体。结果表明:玉米AAP基因的CAI、ENc、GC值分别为0.269、35.48、65.3%,表明其密码子偏好性较弱,且在编码蛋白过程中偏好以G/C结尾;RSCU聚类分析表明,玉米AAP基因与单子叶禾本科植物的使用偏好性相近,且同源关系也较近;而中性、ENC以及PR2绘图分析显示,玉米AAP基因密码子偏好性受自然选择影响较大;密码子使用频率分析表明,大肠杆菌比酵母表达系统更适合作为玉米AAP基因的异源表达受体,水稻更适合作为遗传转化受体。本研究为今后玉米AAP的功能验证及转基因植物培育等提供了研究基础。

Amino acid permease(AAP)is involved in the absorption and transport of amino acids in plants,thereby altering plant growth and development.The study of codon preference of AAP gene is of guiding significance for heterologous expression of AAP gene,functional verification and improvement of its genetic transformation system.Codon W,EMBOSS,Origin 2021 and SPSS were used to perform clustering,neutral,ENC and PR2-plot of AAP gene codons of 25 species,and the best heteroexpression receptor and genetic transformation receptor of maize AAP were selected.The results showed that CAI,ENc and GC values of maize AAP gene were 0.269,35.48 and 65.3%,respectively,indicating that the codon preference of maize AAP gene was weak,and the protein encoding process preferred to end in G/C.RSCU clustering analysis showed that maize AAP gene was similar to monocotyledonous grasses in terms of use preference and homologous relationship.The analysis of neutral,ENC and PR2 plots showed that the codon preference of maize AAP was greatly affected by natural selection.The codon frequency analysis showed that Escherichia coli was more suitable as heterologous expression receptor of maize AAP gene than yeast expression system,and rice was more suitable as genetic transformation receptor.This study provides a basis for the functional verification of maize AAP and the cultivation of transgenic plants.