水稻ABA受体OsPYLs基因家族的鉴定和功能研究

发布时间：2018-01-27 07:07

本文关键词： 水稻 ABA受体 OsPYLs OsPP2Cs 干旱胁迫冷胁迫种子萌发　出处：《中国科学院大学(中国科学院东北地理与农业生态研究所)》2017年博士论文　论文类型：学位论文

【摘要】：ABA是一种重要的植物激素,参与调控植物生长发育的各个方面,包括:种子的休眠、萌发、幼苗的生长等。此外,ABA又是一种抗胁迫激素,响应各种生物和非生物胁迫,如:干旱、盐碱、低温冷害等。水稻作为重要的粮食作物,经常受到干旱、低温等逆境环境的影响,严重威胁着水稻的产量和粮食安全。由于ABA在抵御逆境胁迫中的重要功能,ABA受体获得广泛而深入的研究,以探索其抵御逆境的分子机制。自拟南芥ABA受体PYR/PYL/RCARs基因家族发现以来,ABA信号转导途径及其抗逆的分子机制也逐渐被阐明,并获得一致认可。但在单子叶植物水稻中并没有太多报道,本论文利用拟南芥14个PYR/PYL/RCAR基因的氨基酸序列在水稻基因组数据库中进行比对分析,发现在水稻中含有13个OsPYLs同源基因,其中有3个(OsPYL11~13)在N端或C端有大片段的缺失,被认为是无功能的。所以本课题只克隆了其他10个OsPYLs基因(OsPYL1~10),来研究它们的表达模式和生物功能。主要研究结果如下:1、OsPYLs基因家族的表达具有组织特异性。OsPYL7/8在胚中表达量较高,OsPYL3和OsPYL5在叶中表达量较高,OsPYL1在根中表达量较高,OsPYL2/9在所有组织中表达量都较高。2、OsPYLs基因家族对ABA的响应具有复杂性和多样性。一些基因的表达是受ABA下调的,如:OsPYL1、OsPYL2/9和OsPYL3;而一些基因的表达是受ABA上调的,如:OsPYL4;当然,有些基因表达不受ABA的影响,如OsPYL5、OsPYL7/8 和 OsPYL10。3、OsPYLs蛋白定位在细胞质和细胞核内。4、在酵母和烟草中研究了10个OsPYLs蛋白与5个OsPP2Cs蛋白之间的互作关系,发现OsPYLs选择性的与OsPP2Cs互作,它们之间的互作有的是依赖于ABA的,有的是不依赖于ABA的。5、OsPP2Cs以不依赖于ABA的方式决定OsPYLs-OsPP2Cs复合物的亚细胞定位。6、为了研究OsPYLs基因家族的生物功能,我们分别获得了OsPYL3和OsPYL9过表达转基因水稻。萌发阶段对ABA的敏感性实验分析发现,OsPYL3和OsPYL9过表达转基因水稻在种子萌发阶段对ABA超敏感,且OsPYL9过表达转基因水稻较OsPYL3过表达转基因水稻对ABA有更高的敏感性;干旱胁迫实验分析发现,OsPYL3和OsPYL9过表达转基因水稻气孔关闭速率快,失水速率慢,提高了水稻对干旱胁迫的抵抗能力;冷胁迫实验分析发现,OsPYL3和OsPYL9过表达转基因水稻细胞膜稳定性增强,提高了水稻对冷胁迫的耐受能力。总之,我们发现并总结了水稻ABA受体OsPYLs基因家族一些未被前人报道的特征,这一发现极大可能为提高水稻的抗胁迫能力提供新的研究思路和研究视角。
[Abstract]:ABA is an important phytohormone involved in the regulation of plant growth and development, including seed dormancy, germination, seedling growth and so on. In response to various biological and abiotic stresses, such as drought, salt and alkali, cold chilling, etc. As an important food crop, rice is often affected by drought, low temperature and other stress environment. It is a serious threat to the yield and food security of rice. Because of its important function in resistance to stress, ABA receptor has been widely and deeply studied. Since the discovery of Arabidopsis ABA receptor PYR/PYL/RCARs gene family, its signal transduction pathway and its molecular mechanism of stress resistance have also been elucidated. But not much has been reported in monocotyledonous rice. In this paper, the amino acid sequences of 14 PYR/PYL/RCAR genes of Arabidopsis thaliana were compared in rice genome database, and 13 OsPYLs homologous genes were found in rice. There are three OsPYL1113) with large fragment deletion at the N-terminal or C-terminal. Therefore, only 10 other OsPYLs genes were cloned to study their expression patterns and biological functions. The main results are as follows: 1. The expression of OsPYLs gene family was tissue specific. The expression of OsPYL7 / 8 in embryos was higher. The expression of OsPYL3 and OsPYL5 was higher in leaves. The expression of OsPYL1 in root was higher than that of OsPYL2 / 9 in all tissues. The response of OsPYLs gene family to ABA is complex and diverse. Some genes are down-regulated by ABA, such as: OsPYL1, OsPYL2 / 9 and OsPYL3; Some genes were up-regulated by ABA, such as: OsPYL4; Of course, some genes are not affected by ABA, such as OsPYL5, OsPYL7 / 8 and OsPYL10.3OsPYLs are located in cytoplasm and nucleus. The interaction between 10 OsPYLs proteins and 5 OsPP2Cs proteins was studied in yeast and tobacco. The selective interaction between OsPYLs and OsPP2Cs was found. The interaction between them is either dependent on ABA or not on ABA. 5. In order to study the biological function of OsPYLs gene family, OsPP2Cs determines the subcellular localization of OsPYLs-OsPP2Cs complex in a manner independent of ABA. We obtained OsPYL3 and OsPYL9 overexpression transgenic rice respectively. The sensitivity to ABA in germinating stage was analyzed. OsPYL3 and OsPYL9 overexpression in transgenic rice was hypersensitive to ABA during seed germination. OsPYL9 overexpression was more sensitive to ABA than OsPYL3 overexpression. Drought stress analysis showed that OsPYL3 and OsPYL9 overexpressed transgenic rice stomatal closure rate was fast, water loss rate was slow, improved the resistance of rice to drought stress. Cold stress analysis showed that OsPYL3 and OsPYL9 overexpression of transgenic rice cell membrane stability enhanced, improve the tolerance of rice to cold stress. We have found and summarized some characteristics of rice ABA receptor OsPYLs gene family that have not been reported by previous researchers. This discovery may provide a new way of thinking and research perspective for improving the resistance of rice to stress.
【学位授予单位】：中国科学院大学(中国科学院东北地理与农业生态研究所)
【学位级别】：博士
【学位授予年份】：2017
【分类号】：S511;Q943.2

【相似文献】