拟南芥P4-ATPase的β亚基成员ALIS1/3调控根发育的功能研究

P4-ATPase是一类真核生物特有的磷脂内翻酶，具有调控生物膜磷脂不对称分布和细胞内膜系统转运等功能，在许多重要的生理活动中都起着至关重要的作用。植物P4-ATPase一般由具有催化功能的α亚基（ALA）和非催化功能的β亚基（ALIS）形成异源二聚体。然而，目前有关植物ALISs的生理功能还未见报道。我们前期研究发现，拟南芥ALIS1和ALIS3在根中大量表达，alis1alis3功能缺失双突变体表现出根的胚后发育严重受阻、生长素分布紊乱、PINs蛋白运输发生异常等表型。本项目拟综合多种研究手段，系统研究ALIS1和ALIS3在拟南芥根生长发育过程中的功能，探索它们调控P4-ATPase活性、维持生长素极性运输以及参与根胚后发育的机理，旨在为揭示植物P4-ATPase的功能以及植物根发育的分子机制相关研究提供新的实验证据和理论依据，预期研究结果具有重要的科学意义和潜在的应用价值。

P4-ATPase is a unique class of lipid translocases which is existed only in eukaryotes. This protein family mainly play roles on the regulation of the lipid asymmetry between the two leaflets of the membrane and the cellular endomembrane transport, etc., which are indispensable for many important physiological activities. Generally, the plant P4-ATPase require a α-subunit (ALA) with catalytic function and the other β-subunit (ALIS) with ALA-interacting activity to form a viable heterodimer. However, the physiological function of ALISs at present was still not investigated. Our preliminary work showed that the Arabidopsis ALIS1 and ALIS3 were abundantly expressed in roots, and the double mutant of loss-of-function of these two genes named alis1alis3 exhibited many abnormal phenotypes including the retarded root development after embryo, the auxin distribution in disorder and the defect of protein trafficking of PINs. Therefore, we propose to systematically focus on ALIS1 and ALIS3 by various research means; and attempt to explain their functions involved in the growth and development of root in Arabidopsis thaliana as well as the mechanisms in regulating P4-ATPase activity, maintaining the polar transport of auxin and participating in the root development after embryo; the final research goal is to provide the new experimental evidence and theoretical basis for the related research on the molecular mechanisms of the function of P4-ATPase and the root development in plant. These prospective results are of great reference value in both theory and practice.