不同成熟果色辣椒中PSY1基因的差异表达分析

Differential Expression Analysis of PSY1 Gene in Peppers with Different Ripe Fruit Colors

为了研究PSY1基因在辣椒不同成熟果色形成过程中的作用机理,以Y15016、Y15016-2、SP01、SP02、Z1为材料,克隆PSY1基因并进行时空表达分析,结合部分生物信息学方法,对PSY蛋白功能性质及辣椒不同果色材料中PSY1基因的表达情况进行研究分析。结果表明:5个品种辣椒中均能克隆到PSY1全长基因,且序列无差异;基因结构分析表明,辣椒PSY1基因包含6个外显子、5个内含子,全长为2 844 bp,其CDS全长为1 260 bp,编码419个氨基酸。序列比对和进化树分析表明,辣椒PSY蛋白与同科的番茄、烟草同源PSY蛋白在亲缘关系上最为接近。qRT-PCR分析结果显示:PSY1基因在试验选用的5个品种辣椒根、茎、叶、花组织中均显示表达,在根组织中表达量最低,叶组织中的表达量最高;在橙色突变体Y15016-2的表达量总体高于其在野生型Y15016中的表达量,而在黄色突变体SP02中,其表达量明显低于野生型SP01;在果实不同发育阶段,PSY1基因除Ⅲ期表达有所降低外,其表达量随果实发育总体呈现上升趋势,且在不同果色材料的成熟期(Ⅳ—Ⅴ期)达到最大值。PSY1基因启动子分析结果显示,供试材料中其序列未见差异。结果表明,在不同果色辣椒的果色形成过程中,PSY1基因的差异表达可能起到了较为重要的作用。

In order to study the mechanism of PSY1 gene in different ripe fruit colors of peppers,Y15016,Y15016-2,SP01,SP02 and Z1 were used as materials,and the functional properties of PSY protein and the expression of PSY1 gene in different fruit color materials of pepper were studied and analyzed by combining some bioinformatics methods.The results showed that the full-length PSY1 gene could be cloned in all five pepper varieties,and there was no difference in sequence.Gene structure analysis showed that the PSY1 gene contained six exons and five introns with a total length of 2844 bp,and its CDS contained 1260 bp and encoded 419 amino acids.Sequence alignment and phylogenetic tree analysis showed that the PSY protein of pepper was the closest to the homologous PSY protein of tomato and tobacco of the same family.The results of qRT-PCR analysis showed that the expression level of PSY1 gene in the five materials was lowest in the root tissue and highest in the leaf tissue.Besides,the PSY1 gene was expressed in all the tissues of these materials.The expression level of orange mutant Y15016-2 was higher than that of wild-type Y15016,while that of yellow mutant SP02 was significantly lower than that of wild-type SP01.At different stages of fruit development,the expression of PSY1 gene increased with the development of fruits,except for the decrease in stageⅢ,and reached the maximum value at the maturity stage(Ⅳ-Ⅴ)of different fruit color materials.The results of PSY1 gene promoter analysis showed that there was no difference in the sequences in the test materials.The results suggest that the differential expression of PSY1 gene may play an important role in the formation of peppers with different fruit colors.