大白菜BrIQD31基因参与烟草植株抗旱性的功能分析

Functional analysis of BrIQD31 gene in Chinese cabbage involved in drought resistance of tobacco plants

先前研究发现大部分白菜IQD家族基因对干旱胁迫有响应,因此我们对BrIQD31基因做进一步功能研究。首先克隆BrIQD31的核苷酸序列,并对其理化特征和保守结构域进行分析。其次,利用实时荧光定量PCR (qRT-PCR)技术测定该基因在各个组织中的表达谱。再通过载体构建、遗传转化技术获得BrIQD31异源表达烟草植株,研究干旱胁迫处理下植株表型和测定相关生理指标。研究结果,发现BrIQD31包含一个IQ结构域且主要在根和叶中表达。在干旱胁迫下,处于幼苗期的BrIQD31异源表达烟草植株的根长显著短于野生型植株,说明BrIQD31抑制根的生长。在缺水9 d后转基因烟草植株相对野生型植株表现出明显的萎蔫现象,丙二醛、脯氨酸、相对含水量和电解质渗透率变化表明了转基因植株相对野生型植株对缺水胁迫较敏感。

Previous studies have found that most of the IQD family genes in Chinese cabbage respond to drought stress,so we further study the function of BrIQD3 gene.Firstly,the nucleotide sequence of BrIQD31 was cloned,and its physicochemical characteristics and conserved domain were analyzed.Secondly,the expression profile of the gene in various tissues was determined by quantitative real-time PCR(qRT-PCR).Moreover,tobacco plants with Br IQD31 heterologous expression were obtained by vector construction and genetic transformation,and the plant phenotypes and related physiological indicators under drought stress were studied.The results showed that BrIQD31 contained an IQ domain and was mainly expressed in root and leave.Under drought stress,the root length of Br IQD31 heterologous expression tobacco plants in seedling stage was significantly shorter than that of wild-type plants,indicating that BrIQD31 inhibited the growth of root.After 9 days of water shortage,the transgenic tobacco plants showed obvious wilting compared with the wild-type plants.Changes in malondialdehyde,proline,relative water content and electrolyte leakage indicated that the transgenic plants were more sensitive to water shortage stress than the wild-type plants.