芋淀粉合成酶AGPase基因的克隆及表达分析

Gene Cloning and Expression Analysis of ADP-glucose Pyrophosphorylase in Colocasia esculenta

通过对‘靖江香沙芋’转录组数据进行功能注释,克隆获得‘靖江香沙芋’淀粉合成酶AGPase的基因,序列全长为1 596 bp,命名为CeApS1(NCBI:Colocasia KU288757,未公布)。该基因编码532个氨基酸,蛋白含有1个NTP_transf_3结构域(Gly^(104)~Pro^(306))和1个Pb H1结构域(Gly^(473)~Ser^(515)),编码产生AGPase小亚基,等电点和分子量分别为6.73和57.6 k D。ApS1在单子叶和双子叶植物中广泛存在,CeApS1与紫萍(AIZ00992.1)中相应蛋白的亲缘关系最近,相似性为83.4%,与草莓(AAS00541.1)、苜蓿(XP_003617925.1)、水稻(AAK27313.1)和小麦(CAA46879.1)等植物中相应蛋白的亲缘关系较远。CeApS1在‘靖江香沙芋’的母芋和子孙芋中表达量较高,在叶片、叶柄和根中低表达。芋球茎中的CeApS1表达水平与球茎发育密切相关,在播种160 d后达到最大值。该基因的表达模式与球茎淀粉含量的积累显著正相关。

Based on the transcriptome data of Colocasia esculenta（L.）Schott,full-length c DNA of ApS1（ADP-glucose pyrophosphorylase small subunit 1）gene was cloned from‘Jingjiang Xiangsha Taro＇,which consisted of 1 596 bp and encoded a protein of 532 amino acids,and tentatively designated as CeApS1（NCBI：Colocasia KU288757,unreleased）. CeApS1 contained a NTP_transf_3 domain（Gly^（104）–Pro^（306））and a Pb H1 domain（Gly^（473）–Ser^（515））. This gene encoded a small subunit of ADP-glucose pyrophosphorylase,and isoelectric point and molecular weight were 6.73 and 57.6 k D,respectively. Results displayed ApS1 existed in monocotyledons and dicotyledons. Blast X showed that ApS1 in Colocasia esculenta shared 83.4% identity with Landoltia punctate,and showed farther phylogenetic relationships with Fragaria ananassa（AAS00541.1）,Medicago truncatula（XP_003617925.1）,Oryza sativa（AAK27313.1）and Triticum aestivum（CAA46879.1）. The CeApS1 transcript widely presented in the main corm,lateral cormels,leaves,petioles and roots of Colocasia esculenta,and displayed higher expression levels in taro corms than those in leaves. The results indicated that there was a significantly positive correlation between CeApS1 transcript expression and starch contents in taro corms.