苹果属小金海棠WRKY48基因克隆与功能初步分析

Clone and preliminary functional analysis of Malus xiaojinensis transcription factors gene WRKY48

试验从苹果属小金海棠(Malus xiaojinensis Cheng et Jiang)中克隆得到一条全长为1116 bp基因,命名为MxWRKY48。MxWRKY48蛋白包含371个氨基酸,亚细胞定位试验表明MxWRKY48是一个细胞核定位蛋白。实时荧光定量PCR结果表明,MxWRKY48在小金海棠新叶中表达量高于茎、根和成熟叶。在高铁(160μmol·L-1)、低铁(4μmol·L-1)、盐(200 mmol·L-1)、低温(2℃)处理时,MxWRKY48在苹果属小金海棠根和新叶表达量均显著上升。转基因试验结果表明,MxWRKY48基因过表达可显著提高转基因拟南芥对低铁、高铁耐受能力。在高铁和低铁胁迫处理时,转基因拟南芥根长、鲜重、铁元素和叶绿素含量显著高于野生型拟南芥。

In this study,a gene with a total length of 1116 bp was isolated from Malus xiaojinensis Cheng et Jiang and named as MxWRKY48.MxWRKY48 encoded 371 amino acids.Subcellular localization revealed that MxWRKY48 was a nucleus localized protein.The qPCR result showed that the expression level of MxWRKY48 in new leaves was higher than that in stems,roots and mature leaves.The results also showed that expression level of MxWRKY48 increased obviously in new leaves and roots under high iron(160μmol·L-1),low iron(4μmol·L-1),salt(200 mmol·L-1)and low temperature(2℃)treatments.The results of transgenic study indicated that the overexpression of MxWRKY48 in transgenic A.thaliana could significantly improve its tolerance to low iron and/or high iron stress.When dealt with high Fe stress and/or low Fe stress,the overexpression of MxWRKY48 in transgenic A.thaliana also led to increased fresh weight and root length,as well as higher contents of Fe and chlorophyll.