外源ABA处理下拟南芥微管结合蛋白AtMAP18功能研究

发布时间：2017-12-27 13:28

本文关键词：外源ABA处理下拟南芥微管结合蛋白AtMAP18功能研究　出处：《沈阳农业大学》2017年硕士论文　论文类型：学位论文

【摘要】：ABA是植物激素中重要的一种,它参与调控植物生长发育的各个阶段。它作为"逆境激素",在植物应对各种胁迫环境的过程中均发挥着非常关键作用。因此研究植物ABA胁迫的机制具有十分重要的科学意义。在生物体的许多细胞活动中均有微管骨架动态变化的参与,并在其中起到重要的作用。已经有研究表明,微管的动态变化参与ABA信号转导途径中。微管的动态变化主要是由微管结合蛋白来调节,但是,目前关于调控植物适应ABA的微管结合蛋白作用的研究报道仍比较罕见。AtMAP18是一种去稳定微管的微管结合蛋白,本研究以拟南芥野生型、AtMAP18过表达(AtMAP18-OE)、突变体(map18)和AtMAP18-RNAi植物为实验材料,通过明确ABA处理下微管结合蛋白AtMAP18的表达模式,观察ABA处理下拟南芥野生型、AtMAP18-OE、map18和AtMAP18-RNAi的形态以及微管的动态变化,测定外源ABA处理下ABA胁迫响应基因的表达量变化,从而揭示ABA下微管结合蛋白AtMAP18的作用。主要结果如下:1.外源ABA处理下,可以明显诱导AtMAP18的表达。2.在正常条件下,AtMAP18-OE、AtMAP18-RNAi,map18与WT的种子萌发率基本达到一致。随着外源ABA处理浓度的增加,AtMAP18-RNAi、map18种子萌发受到抑制,与WT种子萌发率差异逐渐增大;AtMAP18-OE与WT种子萌发率差异不显著。而AtMAP18-OE种子萌发受到的抑制明显小于AtMAP18-RNAi和map18。3.在正常条件下,除AtMAP18-RNAi植株的侧根数略低于野生型外,AtMAP18-OE、map18和AtMAP18-RNAi植株在叶片数、叶面积、主根长和侧根数上与野生型相比无显著差异。在外源ABA处理下,AtMAP18-OE植株的长势明显好于野生型,其侧根数更多、主根长更长、叶面积更大;而AtMAP18-RNAi和map18植株的长势则与AtMAP18-OE植株相反,相比较野生型而言侧根数更少、主根长更短、叶面积更小。4.在外源ABA处理下,与野生型相比,AtMAP18-OE植株中ABF2、ABI3、KIN2和RD29A这4个基因在AtMAP18-OE植株中表达量升高,而在map18和AtMAP18-RNAi植株中表达水平降低。5.在外源ABA处理下,map18植株与WT植株子叶中的微管相比较发现,map18植株的微管更加稳定,而WT植株微管解聚更加明显。综上,ABA可以诱导微管结合蛋白AtMAP18的表达,进而调节微管的动态变化。在外源ABA处理下,AtMAP18的过表达可以诱导ABA响应基因的表达,也对植株的生长起到促进作用,并提高了植株适应ABA的能力。反之,AtMAP18的缺失无法诱导ABA响应基因的表达,抑制了植株的生长,降低了拟南芥对ABA的适应能力,研究结果表明微管结合蛋白AtMAP18参与拟南芥ABA信号途径,并起重要的作用。
[Abstract]:ABA is an important plant hormone, which participates in the regulation of plant growth and development. As a "adversity hormone", it plays a very important role in the process of plant coping with various coercive environments. Therefore, it is of great scientific significance to study the mechanism of plant ABA stress. The involvement of the microtubule framework dynamic changes in many cell activities of the organism and plays an important role in it. Studies have shown that the dynamic changes in microtubules are involved in the ABA signal transduction pathway. The dynamic changes of microtubules are mainly regulated by microtubule binding proteins. However, the current studies on the role of microtubule binding proteins regulating plant adaptation to ABA are still rare. AtMAP18 is a microtubule stabilizing microtubule binding to proteins, in this study, the overexpression of AtMAP18 in Arabidopsis wild type (AtMAP18-OE), and AtMAP18-RNAi (map18) mutant plants as the experimental material, through the clear ABA treatment microtubule binding protein expression patterns of AtMAP18, to observe the dynamic changes of ABA treatment of Arabidopsis wild type and AtMAP18-OE and map18 the morphology of AtMAP18-RNAi and microtubule, determination of exogenous ABA treatment of ABA stress response gene expression, thus revealing ABA AtMAP18 protein function. The main results are as follows: 1. the expression of AtMAP18 can be obviously induced by exogenous ABA treatment. 2. under normal conditions, the seed germination rate of AtMAP18-OE, AtMAP18-RNAi, map18 and WT basically reached the same. With the increase of ABA concentration, the germination of AtMAP18-RNAi and map18 seeds was inhibited, and the seed germination rate of WT increased gradually. There was no significant difference in seed germination rate between AtMAP18-OE and WT. The inhibition of AtMAP18-OE seed germination was less than that of AtMAP18-RNAi and map18. 3. under normal conditions, except for the lateral root number of AtMAP18-RNAi plants was slightly lower than that of wild type, AtMAP18-OE, map18 and AtMAP18-RNAi plants had no significant difference in leaf number, leaf area, main root length and lateral root number compared with wild type. Under the treatment of exogenous ABA, AtMAP18-OE plants were obviously better than that of the wild type, the lateral root number and root length more longer, the greater leaf area; while AtMAP18-RNAi and map18 plants and AtMAP18-OE plants growing on the contrary, compared to wild type, length of taproot and lateral roots and fewer shorter, smaller leaf area. 4., under exogenous ABA treatment, compared with wild type, AtMAP18-OE, ABF2, ABI3, KIN2 and RD29A 4 genes increased in AtMAP18-OE plants, but decreased in map18 and AtMAP18-RNAi plants. 5. under exogenous ABA treatment, map18 plants and WT microcotyledon microtubules showed that map18 microtubule was more stable, while WT plant microtubule depolymerization was more obvious. In conclusion, ABA can induce the expression of microtubule binding protein AtMAP18, and then regulate the dynamic changes of microtubules. Under exogenous ABA treatment, AtMAP18 overexpression can induce ABA response gene expression, and also promote the growth of plants, and improve the ability of plants to adapt to ABA. Conversely, the deletion of AtMAP18 could not induce the expression of ABA responsive genes, inhibit the growth of plants, and reduce the adaptability of Arabidopsis to ABA. The results showed that AtMAP18 was involved in ABA signaling pathway and played an important role in Arabidopsis thaliana.
【学位授予单位】：沈阳农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：Q946

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