芋扩展蛋白基因家族的全基因组鉴定及其在球茎膨大中的表达分析

Genome-wide identification and expression analysis of expansin gene family in corm expansion of Colocasia esculenta

扩展蛋白是一类具有促进细胞壁伸长和增加细胞壁柔韧性作用的蛋白。本研究基于芋全基因组范围鉴定扩展蛋白基因,并分析该家族基因结构特征、系统发育及其在芋球茎膨大中的表达模式。结果表明,芋全基因组包含31个扩展蛋白基因,分布在芋8条染色体及2个重叠群上。在芋和拟南芥、水稻、马铃薯等4个物种中的扩展蛋白基因进行系统发育树分析中,所有的扩展蛋白基因划分到4个亚家族中,其中EXPA有23个,EXPB有5个,EXLA有1个,EXLB有2个。共线性分析表明,芋和拟南芥之间存在7对共线性扩展蛋白基因。基因表达分析发现,芋扩展蛋白基因家族不同成员在不同组织中有不同的表达模式,其中CeEXPA 2、CeEXPA 11、CeEXPA 13、CeEXPA 23和CeEXLA 1等5个基因在球茎膨大过程中高表达且差异显著,表明它们可能对芋球茎的膨大发挥了重要的调控作用。本研究结果将有助于了解芋扩展蛋白基因家族的特征及其在球茎膨大中的分子功能,为揭示芋球茎生长发育的分子调控机理提供理论依据。

Expansin is a group of proteins that can promote cell wall elongation and increase cell wall flexibility.The study identified the expansin gene family at taro whole genome,and analyzed the structural characteristics,phylogeny and expression pattern of the expansin gene family in taro corm expansion.The results showed that the whole taro genome contained 31 expansin genes,which were distributed at 8 chromosomes and 2 contigs.Phylogenetic tree analysis of all expansin genes in taro,Arabidopsis,rice and potato species showed that 31 expansin genes of taro were divided into four subfamilies,of which 23,5,1 and 2 expansin genes of taro were in EXPA,EXPB,EXLA and EXLB,respectively.Colinearity analysis showed that there were 7 pairs of colinear expansin genes between taro and Arabidopsis.Gene expression analysis showed that most members of the taro expansin gene family had low gene expression with no significant difference during taro corm expansion,but the five expansin genes(CeEXPA2,CeEXPA11,CeEXPA13,CeEXPA23 and CeEXLA 1)had high gene expression with significant difference during taro corm expansion,suggesting that they could play important roles in regulating the corm expansion.The results of our study will help to understand the characteristics of the taro expansin gene family and its molecular function in taro corm expansion,and provide a theoretical basis for revealing the molecular regulation mechanism of taro corm growth and development.