杏蔗糖转运蛋白基因PaSUC4的获得及功能验证

发布时间：2019-02-19 19:26

【摘要】：杏是蔷薇科(Rosaceae)李亚科(Prunoideae)杏属(Armeniaca)植物,果肉、果仁均可食用。原产中国,野生种和栽培品种资源都非常丰富。在人民生活和园艺产业中占据非常重要地位。可溶性糖的积累是杏果实的重要品质之一,如何提高杏果实的糖含量非常重要。蔗糖是果树体内长距离运输的主要物质,不仅可以通过韧皮部长距离运输到果实中积累糖分,提高果实糖含量,还可以长距离运输到果树其他部位,为营养生长提供所需的能量。而蔗糖的主要运输途径是质外体途径,在完成蔗糖韧皮部装载和卸载的跨膜运输过程中,需要一种载体蛋白(Sucrose carrier,SUC)的作用。这种载体蛋白叫做蔗糖-质子共转运蛋白,也叫做蔗糖转运蛋白(Sucrose transporter,SUT)。本研究运用RT-PCR方法,从“吉农红杏”中获得了蔗糖转运蛋白基因PaSUC4,所得序列长度为2480bp,其中完整开放阅读框1500 bp,预测其编码499个氨基酸,Genbank登录号为KT223003;3’非翻译区长度为945bp。预测编码的蛋白质分子量为53.58KD,等电点为9.31。与张启祥等在杏属梅(Prunus mume)中的PmSUC4氨基酸序列的结果存在98%的相似性。相似性及系统进化分析发现所得蔗糖转运蛋白与蔷薇科其他李属植物中的同类蛋白序列相似性很高,推测其功能也具有保守性。为进一步研究PaSUC4的生物学功能,构建了植物表达载体pCAM-UPN-PaSUC4并进行了烟草遗传转化,获得阳性植株4株,为后续基因的生物功能鉴定工作提供重要试验材料。采集杏不同时期的7个部位进行荧光定量PCR分析。荧光定量PCR显示PaSUC4在杏树的幼果、幼叶、成龄叶、花瓣和新梢器官中均有表达,雌蕊中表达量很少,说明表达水平具有组织差异性。PaSUC4不仅在成龄叶(源组织)中表达,在花瓣、新梢、幼果、幼叶、雌蕊等库组织中也有表达,因此推测PaSUC4可能具有双重功能。
[Abstract]:Apricot is the (Armeniaca) plant of (Prunoideae), (Rosaceae) of Rosaceae. Its flesh and kernel are edible. Native to China, wild species and cultivated varieties are rich in resources. It plays a very important role in people's life and horticultural industry. The accumulation of soluble sugar is one of the important qualities of apricot fruit, and how to improve the sugar content of apricot fruit is very important. Sucrose is the main substance of long distance transportation in fruit trees. It can not only accumulate sugar through phloem and increase sugar content in fruit, but also transport it to other parts of fruit trees. Provide the energy needed for nutritional growth. The main transport pathway of sucrose is the ectoplast pathway, and a carrier protein (Sucrose carrier,SUC) is needed to complete the transmembrane transport of sucrose phloem. This carrier protein is called sucrose-proton co-transport protein, also known as sucrose transport protein (Sucrose transporter,SUT). In this study, the length of sucrose transporter gene PaSUC4, obtained from Jinong Red apricot by RT-PCR method was 2480bp. in which the complete open reading frame 1500 bp, predicted its encoding 499 amino acids, and the Genbank accession number was KT223003;. The length of 3 'untranslated area is 945 BP. The predicted protein molecular weight is 53.58 KD and the isoelectric point is 9.31. There was a 98% similarity between the result of PmSUC4 amino acid sequence and that of Zhang Qi-xiang in (Prunus mume) of Apricot. Similarity and phylogenetic analysis showed that the sucrose transporter had high similarity with the similar proteins in other plants of Rosaceae, and its function was conserved. In order to further study the biological function of PaSUC4, a plant expression vector pCAM-UPN-PaSUC4 was constructed, and 4 positive plants were obtained by genetic transformation of tobacco. Seven parts of apricot in different periods were collected for fluorescence quantitative PCR analysis. Fluorescence quantitative PCR showed that PaSUC4 was expressed in young fruit, young leaf, adult leaf, petal and shoot organs, but not in pistil, indicating that the expression level was different. PaSUC4 was not only expressed in adult leaf (source tissue). It was also expressed in petals, shoots, young fruits, young leaves, pistil and so on. Therefore, we speculated that PaSUC4 might have dual function.
【学位授予单位】：吉林农业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：S662.2

【参考文献】