Stomatal Patterning and Differentiation by Synergistic Interactions of Leucine-rich Repeat Receptor Kinases

陆地植物的成功适应依赖于防止水分流失的机制，同时允许植物与大气之间有效的气体交换。 气体交换是通过气孔复合体进行的，气孔复合体由一对保卫细胞组成，作为一个由突升驱动的阀门。 拟南芥气孔密度增加和气孔簇集突变体的分离表明气孔模式受遗传调控。 本研究项目主要研究细胞间信号传导机制对气孔形成和分化的调控作用。 三个ERECTA家族受体样激酶（RLK）的完全丧失导致高密度气孔簇的产生。 对不同直立家族突变体组合的进一步分析表明，这三种RLKs在气孔分化的两个关键步骤中具有重叠但不同的功能：（1）最初决定原皮层细胞进入增殖分裂或不对称分裂以产生气孔复合体;（2）决定维持气孔干细胞活性并阻止保卫细胞的终末分化。 与已知的气孔模式突变体太多嘴（tmm）的遗传相互作用揭示了化学计量上位性和组合特异性新形态。 这些结果表明，ERECTA家族RLKs的TMM受体样蛋白的负调控，是适当的气孔分化的关键。 具体目标是：1）确定三个ERECTA家族受体激酶在表皮分化过程中的作用; 2）研究三个受体激酶与已知气孔分化参与者的相互作用; 3）通过利用敏化突变体背景来识别气孔模式和分化的新调节剂。拟议的研究可能会导致重要的农业应用，因为操纵气孔分布和模式的能力可能会影响光合效率，从而影响作物的生物量生产。 一名博士后助理、一名研究生和本科生，其中许多是妇女和不同种族背景的人，将有极好的机会获得植物生物学和分子遗传学方面的广泛培训。

The successful adaptation of land plants relied on mechanisms that prevent water loss while allowing efficient gas exchange between plants and the atmosphere. Gas exchange takes place through a stomatal complex, which consists of a pair of guard cells that operate as a turgor-driven valve. Isolation of Arabidopsis mutants with elevated stomatal density and stomatal clustering reveals that stomatal patterning is under genetic regulation. This research project focuses on the cell-cell signaling mechanism regulating stomatal patterning and differentiation. A complete loss of three ERECTA-family receptor-like kinases (RLKs) leads to the generation of high-density stomatal clusters. Further analysis of different erecta-family mutant combinations shows that the three RLKs possess overlapping but distinct functions in two critical steps of stomatal differentiation: (1) the initial decision of protodermal cells to enter proliferative division or asymmetric division to generate stomatal complexes; and (2) the decision to maintain stomatal stem cell activity and prevent terminal differentiation of guard cells. Genetic interactions with a known stomatal patterning mutant, too many mouth (tmm), reveals stoichiometric epistasis and combination-specific neomorphism. These findings suggest that negative regulation of ERECTA-family RLKs by TMM receptor-like protein, is critical for proper stomatal differentiation. The specific aims are:1) to determine the roles of three ERECTA-family receptor kinases during epidermal differentiation.2) to investigate interactions of three receptor kinases with known players of stomatal differentiation.3) to identify novel regulators of stomatal patterning and differentiation by taking advantage of a sensitized mutant background.The proposed research may lead to important agricultural applications, since the ability to manipulate stomatal distribution and patterning may influence photosynthetic efficiency and hence the biomass production of crop plants. A postdoctoral associate, a graduate student and undergraduates, many of whom are women and of diverse ethnic backgrounds, will have excellent opportunities to obtain broad training in plant biology and molecular genetics.