摘要
木薯是世界重要的粮食和生物质能源作物,其块根淀粉含量高达25% ～28%,淀粉积累主要在块根发育的膨大期,影响淀粉积累的代谢通路包括糖代谢和淀粉代谢,而连接这两个代谢通路的主要物质是葡萄糖-6-磷酸,通过葡萄糖-6-磷酸/磷酸转运体（glucose-6-phosphate/phosphate translocator,GPT）转运葡萄糖-6-磷酸进入块根淀粉体合成淀粉。本研究通过生物信息学方法,以木薯、麻风树、蓖麻、胡杨林、可可、拟南芥、水稻、玉米、马铃薯、小麦和大豆的GPT为研究对象,对其核酸序列、氨基酸序列、导肽、跨膜拓扑结构、疏水性/亲水性、蛋白质二级结构、亚细胞定位的分析及预测。结果表明,GPT在不同植物中氨基酸组成成分基本一致,α-螺旋、延伸链和无规则卷曲是其重要的结构元件,含有叶绿体转运肽,无线粒体目标肽,整条肽链表现为疏水性,主要存在内质网和线粒体上。利用qRT-PCR对木薯膨大期GPT基因表达水平进行分析表明GPT对木薯块根膨大期淀粉累积有促进作用。
Cassava is an important staple and bioenergy crops in the world, its tuber starch content is up to 25%～28%and the starch is mainly accumulated in the expansion stage. The metabolic pathway of affecting cassava starch accumulation includes glucose metabolism and starch metabolism, and glucose-6-phosphate is one kind of matter to connect starch and sugar pathways. The glucose-6-phosphate/phosphate translocator（GPT） transfers glucose-6-phosphate into amyloplast to synthesize starch. In this study, Manihot elculenta Crantz, Jatropha curcas L., Ricinus communis Linn, Populus euphratica, Theobroma cacao, Arabidopsis thaliana, Oryza sativa, Zea mays, Solanum tuberosum, Triticum aestirum and Glycine max were selected as the objects. Their nucleotide sequences, amino acid sequences, leader peptides, transmembrane topology, hydrophobicity/hydrophilicity, secondary structure of protein and subcellular localization of GPT were analyzed and predicted by using bioinformatics method. The results showed that amino acid sequences of GPT in different plants were similar. Alpha helix, extension chain and random coil were important structural elements of GPT, which contained a chloroplast transit peptide and a mitochondria target peptide. The whole peptide was hydrophobic, and mainly existed in the endoplasmic reticulum and mitochondria. The analysis of GPT gene expression level in cassava expansion stage by using q RT-PCR showed that GPT played an important role in starch accumulation.
作者
晋琳
李开绵
秦于玲
陈松笔
Jin Lin;Li Kaimian;Qin Yuling;Chen Songbi(Institute of Tropical Agriculture and Forestry, Hainan University, Haikou, 570228;Institute of Tropical Biosciences and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou, 571101;Tropical Crops Genetic Resources Institute, Chinese Academy of Tropical Agricultural Sciences, Key Laboratory of Conservation and Utilization for Cassava Germplasm Resources, Danzhou, 571737)
出处
《基因组学与应用生物学》
CAS
CSCD
北大核心
2018年第6期2467-2476,共10页
Genomics and Applied Biology
基金
NSFC-CGIAR国际合作重点项目(31361140366)
国家科技支撑项目(2015BAD15B01)共同资助
