拟南芥仅含START结构域亚家族基因特性与功能分析

发布时间：2018-06-07 01:29

本文选题：拟南芥 + START结构域　；参考：《中国农业科学》2017年17期

【摘要】：【目的】分析拟南芥中仅含START结构域(the lipid/sterol-binding St AR-related lipid transfer protein domains)亚家族成员的启动子元件及表达特性,阐明启动子元件与表达特性的相互关系,为明确仅含START结构域亚家族的生物学功能,解析植物生长发育机理、更好地促控植物生长提供理论依据。【方法】利用生物信息学方法分析仅含START结构域亚家族6个成员的亲缘关系及各自启动子区所包含的所有元件,对启动子元件的功能进行分析和分类;利用real-time PCR方法研究亚家族成员的表达特性;用突变体分析确认基因的功能;分析通过启动子元件分析预测的基因功能与通过突变体分析确认的基因功能间的相关性,为基因的功能和作用机制分析提供科研思路和方法。【结果】生物信息学分析表明,拟南芥中仅含START结构域亚家族成员共6个,分为3个分支,每个分支一对基因,每一对基因中均有一个基因的启动子中含有高转录水平元件5′UTR Py-rich stretch,6个亚家族成员的启动子区均含有多个光、激素和逆境响应元件,也存在各自特异的响应元件;用real-time PCR分析基因的表达量,结果与生物信息学预测结果一致:At3g13062的表达量明显高于同分支的At1g55960,At3g23080的表达量明显高于同分支的At4g14500,At1g64720的表达量明显高于同分支的At5g54170。组织定位分析表明亚家族成员有特异的时空表达特性:At3g13062和At1g55960在幼苗期就有明显表达,但At3g13062主要在子叶、下胚轴和根中表达,而At1g55960主要在根中表达量较多;在成苗期拟南芥中,At3g13062主要在叶片中表达,在根中表达量较少;而At1g55960在成苗期拟南芥的叶片和根系的表达量均较多;At3g23080和At4g14500在幼苗期表达量较少,而在成苗期表达量增加,At3g23080主要分布于莲座叶中,At4g14500主要分布于莲座叶叶柄部。上述结果表明仅含START结构域亚家族成员可能在拟南芥不同时期和不同的部位分别行使着功能。利用生物信息学对启动子元件分析发现,各个基因均具有胚乳特意表达的Skn-1 motif元件,暗示着该家族基因可能参与调控胚乳的发育,进而影响种子的活力和萌发;通过对At3g23080和At4g14500的T-DNA插入突变体种子的分析表明,At3g23080和At4g14500表达量下降均会导致种子活力和萌发率的下降,这与生物信息学预测结果一致。【结论】拟南芥中仅含START结构域的亚家族有6个成员;6个亚家族成员可能在光、激素和逆境调控的发育过程中具有重要的作用;含START结构域的亚家族6个成员虽然同源关系较近,但具有各自的时空表达特性,在拟南芥的不同组织和不同发育时期执行着各自的功能。基因启动子元件与基因功能有直接关系,启动子区具有胚乳特意表达Skn-1 motif元件的At3g23080和At4g14500表达量下降均会导致种子活力和萌发率下降。
[Abstract]:[objective] to analyze the promoter elements and expression characteristics of the members of the lipid/sterol-binding St AR-related lipid transfer protein domains) subfamily containing only the START domain in Arabidopsis thaliana, and to elucidate the relationship between the promoter elements and the expression characteristics. In order to clarify the biological function of the subfamily containing only START domain, the mechanism of plant growth and development was analyzed. [methods] bioinformatics was used to analyze the relationship among the six members of the START domain subfamily and all the elements contained in their respective promoter regions. The function of promoter element was analyzed and classified, the expression characteristics of subfamily members were studied by real-time PCR method, the function of gene was confirmed by mutants analysis. The correlation between gene function predicted by promoter element analysis and gene function confirmed by mutant analysis was analyzed, which provided scientific research ideas and methods for gene function and mechanism analysis. [results] Bioinformatics analysis showed that, In Arabidopsis thaliana, there are only 6 members of START domain subfamily, which are divided into three branches, each branching a pair of genes. In each pair of genes, the promoter of one gene contains a high transcription level element 5'UTR Py-rich retch, and the promoter regions of the six subfamily members contain multiple light, hormone and stress response elements, as well as their own specific response elements. Real-time PCR was used to analyze the expression of the gene. The results were consistent with the bioinformatics prediction. The expression of 1: At3g13062 was significantly higher than that of At1g55960U / At3g23080 with the same branch, which was significantly higher than that of At4g14500 / At1g64720 with the same branch. Tissue localization analysis showed that the members of the subfamily had special temporal and spatial expression characteristics: At3g13062 and At1g55960 were expressed obviously at seedling stage, but At3g13062 was mainly expressed in cotyledons, hypocotyls and roots, while At1g55960 was mainly expressed in roots. At3g13062 was expressed mainly in leaves and less in roots in Arabidopsis thaliana at seedling stage, while At1g55960 expression in leaves and roots of Arabidopsis thaliana was more than that in leaves and roots of Arabidopsis thaliana at seedling stage, and the expression of At3g23080 and At4g14500 in seedling stage was less than that in seedling stage. At the seedling stage, At3g23080 was mainly distributed in the leaves of rosette, and At4g14500 was mainly distributed in the petiole of rosette leaves. These results suggest that only members of the START domain subfamily may function at different stages and parts of Arabidopsis thaliana. By bioinformatics analysis of promoter elements, it was found that all genes had Skn-1 motif elements specifically expressed in endosperm, suggesting that the family genes might be involved in regulating the development of endosperm, thus affecting the vigor and germination of seeds. The analysis of At3g23080 and At4g14500 T-DNA inserted mutant seeds showed that the decreased expression of At3g23080 and At4g14500 resulted in the decrease of seed vigor and germination rate. [conclusion] in Arabidopsis thaliana, there are 6 members of the subfamily with only START domain, 6 members may play an important role in the development of light, hormone and stress regulation. Although the six members of the subfamily with START domain share close homology, they have their own spatio-temporal expression characteristics and perform their own functions in different tissues and developmental stages of Arabidopsis thaliana. The gene promoter element is directly related to gene function. The decrease of At3g23080 and At4g14500 expression in the promoter with endosperm specially expressing Skn-1 motif elements will lead to the decrease of seed vigor and germination rate.
【作者单位】：河北农业大学生命科学学院/河北省植物生理和分子病理学重点实验室;
【基金】：河北省自然科学基金(C2017204060)
【分类号】：Q943.2

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