荸荠颗粒结合型淀粉合成酶基因的克隆与表达分析

发布时间：2018-04-10 08:52

本文选题：荸荠　切入点：淀粉　出处：《扬州大学》2017年硕士论文

【摘要】：荸莽(Eleocharis tuberosa)是莎草科荸荠属多年生水生草本植物,原产于中国和印度。淀粉是荸荠球茎的主要贮藏物质,由直链淀粉和支链淀粉组成,其中直链淀粉可以被完全分解为麦芽糖和少量的葡萄糖,而支链淀粉水解后得到的产物为麦芽糖、葡萄糖以及分子量比较大的极限糊精。一般情况下荸荠水分和可溶性固形物含量较高,淀粉含量较低,渣少,味甜,口感较好,因此直链淀粉的含量及其与支链淀粉的比例将影响着荸莽球茎的品质。前人研究已证明,颗粒结合型淀粉合成酶(GBSS)在直链淀粉合成过程中起着关键作用。论文以荸荠品种'红宝石'为材料,克隆得到荸荠GBSS基因的全长cDNA序列、基因组DNA序列,并分析GBSS基因在荸荠品种'红宝石'、'苏州荸荠'中的表达特性。主要结果如下:1、以荸荠'红宝石'幼嫩球茎总RNA为模板,采用RACE-PCR技术,克隆得到长为2 265 bp的荸荠GBSS cDNA序列,其开放阅读框为1 818 bp,编码605个氨基酸,编码蛋白的分子量为66.5 kDa。2、以荸荠'红宝石'幼嫩球茎为材料,提取荸荠总DNA,克隆得到长4 578 bp的GBSS基因DNA序列,包括13个外显子和12个内含子,其中第1内含子最大,长504 bp,第7内含子最小,长83 bp;第1外显子最大,长532 bp,第5外显子最小,长64 bp,有5个外显子的长度小于100 bp。3、采用qPCR技术分析了荸荠GBSS的表达特性。荸荠GBSS在不同组织中的表达规律为:球茎匍匐茎叶状茎分株芽,且球茎中GBSS表达量显著高于其他组织,GBSS在叶状茎及分株芽中表达量极低。在'红宝石'和'苏州荸荠'的球茎膨大过程中,GBSS表达量均表现为先上升后下降的趋势;且GBSS在'红宝石'球茎膨大过程中的表达量均高于'苏州荸莽'球茎膨大各时期的表达量,膨大中期表达量达最高,匍匐茎中表达量最低。
[Abstract]:Eleocharis tuberosa is a perennial aquatic herb of water chestnut of Cyperaceae, native to China and India.Starch is the main storage material in the bulb of water chestnut, which is composed of amylose and amylopectin, in which amylose can be completely decomposed into maltose and a little glucose, and the product of amylopectin hydrolysis is maltose.Glucose and limit dextrin with higher molecular weight.In general, water content and soluble solids of water chestnut are higher, starch content is lower, residue is less, taste is sweet, taste is better, so the content of amylose and its ratio to amylopectin will affect the quality of corm.Previous studies have proved that granular-bound starch synthase (GBSS) plays a key role in amylose synthesis.In this paper, the full-length cDNA sequence and genomic DNA sequence of GBSS gene of water chestnut were cloned from the water chestnut variety 'ruby', and the expression characteristics of GBSS gene in 'ruby' Suzhou water chestnut were analyzed.The main results were as follows: 1. Using the total RNA of young bulbs of Chinese water chestnut 'ruby' as template, the GBSS cDNA sequence of 2 265 BP was cloned by using RACE-PCR technique. The open reading frame was 1 818 BP, encoding 605 amino acids.The molecular weight of the encoded protein was 66.5 kDa.2.The total GBSS of water chestnut was extracted from the young bulb of Chinese water chestnut 'ruby', and the DNA sequence of GBSS gene was cloned, including 13 exons and 12 introns, in which the first intron was the largest.The length of 504 BP, the smallest intron 7, 83 BP, the largest exon 1, 532bp, the smallest exon 5, 64 BP, and the length of 5 exons were less than 100bp.3.The expression characteristics of GBSS in water chestnut were analyzed by qPCR technique.The expression patterns of GBSS in different tissues were as follows: bulb stolon leaflike shoot ramet, and the expression of GBSS in corm was significantly higher than that in other tissues in leaf stem and ramet bud.During the bulbous enlargement of 'ruby' and 'Suzhou water chestnut', the expression of GBSS increased first and then decreased.The expression of GBSS in the process of 'ruby' bulbous expansion was higher than that in 'Suzhou' bulbous expansion stage, and the highest expression was found in the middle stage of expansion, and the lowest in stolon.
【学位授予单位】：扬州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S645.3

【参考文献】