【作者】 薛莉；

【导师】 黎家；

【作者基本信息】 兰州大学 ， 植物学， 2012， 硕士

【摘要】 植物类受体激酶(RLKs, receptor-like kinases)是一类重要的蛋白激酶,参与植物生长发育调控的许多过程。在模式植物拟南芥中,有600多个RLKs.其中富含亮氨酸重复序列类受体激酶(LRR-RLKs)家族有223个成员,是最大的一个亚家族。它们定位于细胞膜上,有三个结构域：一个胞外结构域、一个胞内结构域以及一个单次跨膜结构域。到目前为止,只有其中少数基因的功能被阐释,如BRI1、BAK1、FLS2、EFR、SERKs、EMS1等。为了揭示其余LRR-RLKs的功能,本实验室在前期的研究工作中构建了180多个LRR-RLKs的超表达载体,并转入野生型拟南芥中,本研究在此基础上对这些超表达转基因植株进行鉴定,成功获得了102个LRR-RLKs的稳定表达转基因植株,并对它们的表型进行了观察研究。在鉴定LRR-RLKs的转基因植株过程中,发现其中两个同源基因TRR1(Tapetum Related RLK1)和TRR2的超表达植株与野生型相比,叶片更狭长、更短。对T-DNA插入缺失双突变体trr1trr2的研究发现,trr1trr2的绒毡层细胞膨大,但一部分小孢子母细胞可以正常发育形成可育的花粉粒,植株产生正常种子；更严重的表型是小孢子母细胞不能正常发育形成小孢子,花药塌陷造成植株的败育。这两种表型经常出现在同一个花药上,一侧药室的小孢子母细胞不能形成正常花粉,而另一侧药室的绒毡层细胞膨大。进一步研究发现,双突变体的小孢子母细胞不正常增殖、绒毡层开始变大,分别发生在花药发育的第6期和第9期。RT-PCR结果显示,与野生型相比,在trrl trr2中,绒毡层早期、中期和后期发育相关的基因SPL、DYT1和MS2的表达量分别被上调。酵母双杂交结果表明,TRRl和TRR2可能参与了SERKs等受体激酶所调控的花药发育信号途径。更多还原

【Abstract】 Receptor-like protein kinases (RLKs) are a group of specific protein kinases, which play important roles in plant growth and development. Leucine-rich repeat (LRR)-RLK is the largest family of the RLK superfamily in Arabidopsis containing223members. There are three domains in a typical LRR-RLK:an extracellular domain, an intracellular domain and a single-pass transmembrane domain. Functions of a handful of LRR-RLKs have been defined, such as BR11, BAK1, FLS2, EFR, SERKs, and EMS1. To reveal the functions of other LRR-RLKs, transgenic plants overexpressing these genes were created and screened in wildtype Arabidopsis. Western blot analysis was employed to confirm the expression of transgenes in transgenic plants. Transgenic plants were identified for a total of102LRR-RLKs for phenotypic analyses.Overexpression of TRR1(Tapetum Related RLK1) and TRR2displayed short and narrow leaves in their transgenic plants. Loss-of-function analyses indicated that TRR1and TRR2play important roles in anther development, controlling degradation of tapetum and microsporogenesis. Double null mutant trrl trr2shows enlarged tapetum and a few microsporocytes can develop to produce fertile microspore and mature pollen. More severe phenotypes were also observed that the microsporocytes could not develop to produce pollen, and the anther finally collapsed. These two phenotypes can exit within one anther, resulting in sterile microsporocytes in one collapsed pollen sac, and enlarged tapetum in another pollen sac. The defective microsporocytes and tapetum can be observed at stage6and stage9of anther development, respectively. RT-PCR analyses indicated that the expression levels of tapetum related genes DYT1, SPL and MS2were all upregulated in trrl trr2mutant. Our data suggested that TRR1and TRR2could be involved in the anther development signaling network mediated by SERKs, SPL, DYT1and MS2.更多还原