萝卜HAK/KUP/KT基因家族鉴定与表达特性分析

Identification and expression characteristics analysis of HAK/KUP/KT gene family in radish

钾元素是植物生长发育过程中必需的主要矿质营养元素之一,对作物的产量和品质有决定性影响,细胞内K+含量水平在很大程度上受K+转运蛋白控制。通过生物信息学方法从全基因组水平鉴定出萝卜K^(+)转运蛋白HAK/KUP/KT基因家族成员,并对其基因结构、蛋白质特性、保守基序、染色体定位、启动子顺式作用元件、系统进化及表达特性等进行分析。结果表明,鉴定出的17个萝卜HAK/KUP/KT基因不均等地分布在萝卜6条染色体及Scaffold00840上,根据与拟南芥的同源关系将其命名为RsHAK1~RsHAK17;RsHAKs基因结构、保守基序、蛋白质理化特性等均具有高度保守性,启动子区域存在大量与环境因素、植物激素、逆境胁迫应答等有关的顺式作用元件;系统进化分析结果显示,17个RsHAKs基因聚为4个亚家族,全基因组复制事件是RsHAKs基因扩张的主要驱动力。转录组和qRT-PCR表达分析结果表明,除RsHAK5仅在萝卜根部表达外,其他RsHAKs在萝卜各器官及发育过程中均有特异性表达,且在高钾渗透胁迫下在叶片中相对表达量显著上调,RsHAK3、RsHAK9、RsHAK11和RsHAK12在根部呈现明显的缺钾诱导表达模式。研究结果为进一步全面解析HAK/KUP/KT基因在萝卜中的生物学功能以及提高萝卜栽培品质提供了一定理论依据。

Potassium is one of the essential main mineral nutrient elements in the process of plant growth and development,and has a decisive impact on the yield and quality of crops.The level of intracellular K+content is largely controlled by K^(+) transport proteins.Members of the radish K+transport protein related HAK/KUP/KT gene family were identified from whole genome-wide level by bioinformatics methods,and the gene structure,protein properties,conserved motifs,chromosomal localization,promoter cis-acting elements,phylogenetic evolution and expression characteristics were analyzed.The results showed that the 17 radish HAK/KUP/KT genes were unequally distributed on six chromosomes and Scaffold00840,and were named RsHAK1-RsHAK17 according to their homology with Arabidopsis.The gene structure,conserved motifs,physicochemical properties of proteins of RsHAKs genes were highly conserved,and there were a large number of cis-acting elements related to environmental factors,plant hormones and responses to adversity stresses in the promoter region.Phylogenetic analysis showed that 17 RsHAKs genes clustered into four subfamilies,and whole genome-wide replication events were the main driver of the RsHAKs genes expansion.The results of transcriptome and qRT-PCR expression analysis showed that except for RsHAK5,which was only expressed in radish roots,other RsHAKs were specifically expressed in different organs and different development processes of radish,and the relative expression in leaves was significantly up-regulated under high potassium osmotic stress.RsHAK3,RsHAK9,RsHAK11 and RsHAK12 showed obvious expression patterns induced by potassium deficiency in roots.Overall,the results provide theoretical basis for further comprehensive analysis of the biological functions of HAK/KUP/KT gene and improving the cultivation quality of radish.