AtELS1基因功能的初步分析

发布时间：2018-07-12 21:58

本文选题：MATE转运蛋白 + ELS1　；参考：《兰州大学》2017年硕士论文

【摘要】：多药和有毒化合物排出蛋白(MATE,multidrug and toxic compound extrusion)广泛存在于生物界,能够作为次级转运系统的一部分对细胞内的化学离子或其它小分子物质浓度进行调节,以应对环境的变化。铁是植物中重要的微量营养元素之一,体内铁元素的稳态调节对于植物的生长发育来说非常重要。在拟南芥的至少58个MATE基因中,只有2个被证明参与了铁稳态调节。本实验室之前对激活标签筛选得到的突变体els1-D(Early Leaf Senescence 1)的研究发现,ELS1编码一个MATE蛋白,其过量异位表达能够导致叶片的早衰,说明MATE蛋白ELS1可能参与衰老过程中营养物质的再分配。但对于它的更进一步认识有待研究,如它具体如何参与此过程、表达模式及调控方式、亚细胞定位以及是否存在其它转运底物等。此外,由于过表达突变体有很多问题不容易解释,所以本论文为更进一步了解ELS1基因的生理功能,着重对其T-DNA插入缺失突变体els1-1进行了研究。通过观察不同时期的植株表型发现缺失突变体els1-1与野生型并无明显差别;通过铁染色检测不同时期幼苗体内铁含量发现缺失突变体els1-1中铁含量多于野生型;对缺失突变体els1-1和野生型进行黑暗诱导实验,发现缺失突变体els1-1衰老晚于野生型;而且对正常条件下生长植株外源施加铁,能延缓els1-D的衰老;对pELS1::GUS转基因植株进行铁处理后GUS染色发现铁能够诱导该基因表达;此外,亚细胞分析发现ELS1定位于细胞的内膜系统。综合以上结果,我们推测ELS1可能定位在拟南芥的液泡膜上,参与将细胞内多余的铁离子运输到液泡中,所以当ELS1缺失以后将打破细胞内铁离子的稳态平衡。但目前对于ELS1参与的植物铁稳态调控中的其它参与因子及详细的调控机制我们还知之甚少,所以需要我们更深入的研究。本研究将拓展我们对植物MATE家族基因功能的认识,有可能为农作物的改良提供理论依据和思路。
[Abstract]:Multidrug and toxic compound extrusion) is widely present in the biological world and can regulate the concentration of chemical ions or other small molecules in cells as part of the secondary transport system in order to cope with environmental changes. Iron is one of the most important micronutrients in plants. Of at least 58 MATE genes in Arabidopsis thaliana, only 2 have been shown to be involved in iron homeostasis regulation. Previous studies in our laboratory on the mutant els1-D (early Leaf Senescence 1) screened for activation tags have found that ESL _ 1 encodes a mate protein, and its over-ectopic expression can lead to premature senescence in leaves. These results suggest that ELS1 may be involved in the redistribution of nutrients during senescence. However, further understanding of it remains to be studied, such as how it participates in this process, how it is expressed and regulated, its subcellular localization and the existence of other transport substrates. In addition, there are many problems in overexpression mutants which are difficult to explain. In order to understand the physiological function of ELS1 gene, the T-DNA insertion deletion mutant els1-1 was studied in this paper. It was found that there was no significant difference between the deletion mutant els1-1 and the wild type by observing the plant phenotypes at different stages, and the iron content in the deletion mutant els1-1 was higher than that in the wild type by iron staining. The dark induction experiments of els1-1 and wild-type mutant showed that els1-1 was older than wild type, and exogenous iron applied to the growth plants under normal conditions could delay the senescence of Els 1-D. Gus staining of pELS1: Gus transgenic plants showed that iron could induce the expression of the gene, and that ELS1 was located in the endomembrane system of the cells by subcellular analysis. Based on the above results, we speculate that ELS1 may be located on the vacuolar membrane of Arabidopsis thaliana and be involved in the transport of excess iron ions into vacuoles. Therefore, the homeostasis of iron ions in the cells will be broken when ELS1 is absent. However, we still know very little about the other factors and detailed regulation mechanism of plant iron homeostasis regulated by ELS1, so we need to study more deeply. This study will expand our understanding of the gene function of plant MATE family and may provide theoretical basis and ideas for crop improvement.
【学位授予单位】：兰州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：Q943.2

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