对萼猕猴桃HMGR基因家族的鉴定及其对淹水胁迫的响应

Identification of the HMGR gene family in kiwifruit (Actinidia valvata)and its response to waterlogging stress

关键词:  3-羟基-3-甲基戊二酰辅酶A还原酶(HMGR), 对萼猕猴桃, 全基因组鉴定, 表达分析, 淹水胁迫

Key words:  3-Hydroxy-3-methylglutaryl coenzyme A reductase(HMGR), Actinidia valvata, genome-wide indentification, expression analysis, waterlogging stress

摘要:

3-羟基-3-甲基戊二酰辅酶A还原酶(HMGR)是萜类化合物生物合成途径中的关键酶,在植物的生长发育和逆境胁迫响应中发挥着重要作用。为了探究AvHMGR基因家族的特性及其在淹水胁迫中的功能,该研究采用生物信息学方法对对萼猕猴桃HMGR基因家族进行了全基因组鉴定,并对其染色体定位、基因结构、蛋白保守结构域、启动子顺式作用元件等进行了系统分析。结果表明:(1)在对萼猕猴桃中共鉴定到12个AvHMGR家族成员,分布于12条染色体上,编码514～597个氨基酸,均定位于内质网。系统进化树将AvHMGR成员分为3个亚家族。(2)启动子分析发现其富含激素与逆境响应顺式作用元件。(3)AvHMGR6b和AvHMGR9a/b在不同组织和果实不同发育时期的表达水平较高; AvHMGR5a/b在盐胁迫12 h时表达升高,参与对短期盐胁迫的响应。(4)淹水胁迫下,对萼猕猴桃叶和根中多个AvHMGR基因表达显著上调,包括AvHMGR5b、AvHMGR6a/b、AvHMGR9a/b和AvHMGR21a,表明AvHMGR在淹水胁迫的响应中发挥着重要作用。该研究结果为进一步研究HMGR基因在淹水胁迫下的功能特征及培育耐涝猕猴桃新种质提供了理论依据。

Abstract:

3-Hydroxy-3-methylglutaryl coenzyme A reductase(HMGR)is a key enzyme in the terpenoid biosynthetic pathway and plays a vital role in plant growth, development, and responses to abiotic stress. To investigate the characteristics of the AvHMGR gene family and its function under waterlogging stress, a genome-wide identification of the AvHMGR gene family in Actinidia valvata was performed using bioinformatics approaches. Comprehensive analyses were conducted on their chromosomal localization, gene structures, conserved protein domains, and cis-acting elements in promoter regions, etc. The results were as follows:(1)A total of 12 AvHMGR family members were identified in the A. valvata genome and were located across 12 different chromosomes. These AvHMGR genes encoded proteins ranging from 514 to 597 amino acids in length, all of which were predicted to be localized in the endoplasmic reticulum. Based on the phylogenetic analysis, AvHMGR members were grouped into three clusters.(2)Promoter analysis revealed abundant hormone-responsive elements and stress-responsive elements within the AvHMGR promoters.(3)Expression profiling showed that AvHMGR6b and AvHMGR9a/b exhibiting relatively high expression levels at different tissues and fruit developmental stages; AvHMGR5a/b were up-regulated after 12 h of salt stress, suggesting their involvement in short-term salt stress response.(4)Under waterlogging stress, multiple AvHMGR genes including AvHMGR5b, AvHMGR6a/b, AvHMGR9a/b, and AvHMGR21a were significantly up-regulated in both leaves and roots, suggesting that AvHMGRs played a critical role in plant responses to waterlogging stress. The sults of this study provides a theoretical foundation for further research on the functional characterization of HMGR in plant responses to waterlogging stress and lays a fundamental basis for future breeding efforts aimed at enhancing kiwifruit tolerance to waterlogging stress.