苎麻XTH家族基因克隆及表达分析

发布时间：2018-04-20 22:28

本文选题：苎麻 + 木葡聚糖内转糖苷酶/水解酶　；参考：《华中农业大学》2017年硕士论文

【摘要】：苎麻是我国特有的纤维作物,苎麻织物具有透气、防霉、轻薄等诸多优点,在纺织业中扮演着重要的角色。苎麻纤维是一种韧皮纤维,植物韧皮纤维发育涉及到韧皮部纤维细胞壁的扩展、加厚等生物学过程。对参与该过程的相关基因表达特性的研究能够推动研究者对苎麻纤维发育进程的认识,有助于从分子水平上对苎麻纤维品质进行改良。木葡聚糖内转糖苷酶/水解酶基因(XTH)在促进植物细胞壁延展以及响应逆境胁迫方面发挥着重要的作用。目前,在拟南芥、水稻、杨树等模式植物中关于XTH家族的研究已较为成熟,而类似的研究在苎麻中还未见报道。本研究以苎麻优质品种“1504”为材料,基于本实验室已有的3个转录组数据库信息,克隆苎麻Bn XTH基因,分析基因的时空表达模式,并通过烟草亚细胞定位实验研究基因在细胞中的表达和分布情况。主要实验结果如下:(1)从转录组中筛选出20条苎麻Bn XTH基因,命名为Bn XTH1-Bn XTH20,并获得其中12个基因的基因组DNA序列,分析基因的内含子-外显子结构和功能域及构建进化树。(2)通过qRT-PCR测定基因在苎麻三季麻不同发育时期和部位的表达情况,研究20条基因时空表达模式,实验结果表明:20条基因在不同发育时期茎的不同部位均有表达,多数基因在头麻和二麻茎部的表达水平高于三麻,其中,Bn XTH11在头麻茎部的表达水平高于二麻和三麻;分析Bn XTH基因在胁迫处理下的表达情况,发现20个基因均能响应干旱、高温、低温胁迫,在干旱和高温胁迫下,Bn XTH11在茎部表达量极显著上升,在低温胁迫下,其表达量出现极显著下降。(3)构建Bn XTH11 GFP载体,转入烟草,进行亚细胞定位分析,发现绿色荧光在细胞膜或细胞壁表达,表明该蛋白可能被转运至细胞膜,最后分泌至细胞壁发挥作用。
[Abstract]:Ramie is a special fiber crop in China. Ramie fabric plays an important role in textile industry because of its many advantages, such as air permeability, mildew resistance, lightness and so on. Ramie fiber is a kind of phloem fiber. The development of plant phloem fiber is related to the extension and thickening of cell wall of phloem fiber. The study of the related gene expression characteristics involved in the process can promote the understanding of Ramie fiber development process and help to improve the Ramie fiber quality at the molecular level. Dextran glucosidase / hydrolase gene XTHplays an important role in promoting cell wall extension and responding to stress. At present, the studies of XTH family in Arabidopsis thaliana, rice, poplar and other model plants have been more mature, but similar studies have not been reported in Ramie. In this study, Ramie Bn XTH gene was cloned from three transcriptome databases of Ramie quality variety "1504", and the temporal and spatial expression pattern of the gene was analyzed. The expression and distribution of genes in tobacco cells were studied by subcellular localization experiment. The main results were as follows: (1) Twenty Bn XTH genes of Ramie were screened from the transcriptome, named Bn XTH1-Bn XTH20, and the genomic DNA sequences of 12 of them were obtained. The structure and functional domain of intron and exon of the gene were analyzed and the phylogenetic tree was constructed. QRT-PCR was used to determine the expression of the gene in different development stages and parts of Ramie, and the spatiotemporal expression patterns of 20 genes were studied. The results showed that 20 genes were expressed in different parts of stem at different developmental stages, and the expression level of most of them was higher in the stem part of head hemp than that in Sanma, and the expression level of Bn XTH11 in the stem part of head hemp was higher than that in the stem of head hemp and Sanma. By analyzing the expression of Bn XTH gene under stress, it was found that 20 genes were able to respond to drought, high temperature and low temperature stress, and the expression of Bn XTH11 in stem was significantly increased under drought and high temperature stress, and increased significantly under low temperature stress. Bn XTH11 GFP vector was constructed and transformed into tobacco for subcellular localization analysis. It was found that green fluorescence was expressed in the cell membrane or cell wall, indicating that the protein might be transported to the cell membrane. Finally secreted to the cell wall to play a role.
【学位授予单位】：华中农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S563.1

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