高粱的玉米黄质环氧化酶基因SbZEP表达与DNA变异分析

Analysis of Expression of Gene SbZEP of Zeaxanthin Epoxidase and DNA Variation in Sorghum

类胡萝卜素是维生素A的前体,是决定高粱籽粒营养品质的关键因素。为改良高粱籽粒营养品质,研究利用生物信息学和分子生物学试验方法对参试高粱类胡萝卜素中叶黄素循环的玉米黄质环氧化酶基因进行表达与DNA变异分析。结果表明,SbZEP为亲水性蛋白,亚细胞定位于内质网和叶绿体上;二级结构则以α-螺旋和无规则卷曲为主,SbZEP蛋白三级结构与预测一致,可信度高达90%;系统进化树分析表明,ZEP蛋白划分为6组,高粱与谷子的ZEP基因同源关系更近,同时在演化上有双子叶与单子叶的演化分隔。顺式作用元件分析表明,SbZEP含有光响应以及防御和应激响应元件,可能参与光反应和防御反应过程。高粱叶片发育过程中SbZEP基因的表达量明显增加;SbZEP在高粱种子、胚珠和茎表达水平较高;DNA重测序数据分析表明,SbZEP存在非同义突变,在不同品系对应不同位点的突变,可能与类胡萝卜素的合成与降解相关。

Carotenoids acting as the precursors of vitamin A is a key factor determining the quality of grains of sorghum.In order to Lay the foundation for molecular breeding to improve the nutritional quality of sorghum grains,in this study,bioinformatics and molecular biology experiments were used to analyze expression and DNA variation analysis of the gene of zeaxanthin epoxidase in the lutein cycle in carotenoids of the tested sorghum.The results showed that SbZEP was hydrophilic protein and subcellular localization on endoplasmic reticulum and chloroplast.The secondary structure of SbZEP protein was mainlyα-helix and random coil.The tertiary structure of SbZEP protein was consistent with the prediction,and the confidence could be as high as 90%.Phylogenetic tree analysis showed that ZEP proteins were divided into 6 groups,and ZEP genes of sorghum were more closely related to those of millet,and there were evolutionary separation of dicots and monocots.cis-acting element analysis showed that SbZEP contained photoresponse and defense and stress response elements,which might be involved in both photoresponse and defense response processes.The expression of SbZEP gene increased significantly during the development of sorghum leaves.The expression level of SbZEP was higher in seed,ovule,and stem of sorghum.DNA resequencing data analysis showed that SbZEP had non-synonymous mutations in different strains and corresponding mutations at different sites,which might be associated with the synthesis and degradation of carotenoids.