芒果F3'5'H基因的克隆及其表达分析

Abstract

黄酮-3',5'-羟基化酶(flavonoid-3',5'-hydroxylase, F3'5'H)是合成飞燕草色素苷的关键酶基因，缺乏F3'5'H的植物不能形成蓝色花，故又被称为“蓝色基因”。本研究根据已经报道的F3'5'H基因的序列设计兼并引物，采用3'RACE和5'RACE方法，克隆得到了一个全长cDNA序列为1598 bp的芒果果实F3'5'H基因。该基因开放阅读框为1539 bp，编码512个氨基酸，分子重量为57.20 KD。对基因组扩增得到了1633 bp长度的片段，分析发现该基因含有一个内含子。通过系统发育分析发现该基因编码的蛋白与石斛、马鞭草等植物具有较近的亲缘关系。对不同芒果品种的F3'5'H基因的表达进行分析发现：红色的贵妃品种中表达量较高，而绿色的桂七品种中表达量较低。 Flavonoid-3',5'-hydroxylase (F3'5'H), was the key enzyme gene for synthesizing delphinidin glycosides; due to the lack of F3'5'H, plants cannot form a blue flower, which was also known as the “blue gene”. According to the design of degenerate primers of F3’5’H gene sequence reported, full- length cDNA sequence of F3'5'H gene of mango fruit was obtained with 3'RACE and 5'RACE method. The full-length cDNA sequence of F3'5'H was 1598 bp, whose open reading frame of the gene was 1539 bp, encoding 512 amino acids, with the molecular weight of 57.20 KD. The 1633 bp length fragment was amplified from genome and analysis, which contained one intron, in 909 - 1003 bp. It was found that the gene encoding for the protein had close relationship with dendrobium, verbena plant through phylogenetic analysis. Expression of F3'5'H gene in different mango varieties showed: the high expression of the “Guifei” varieties, and the expression of green Guiqi varieties with low volume.