小麦水通道蛋白TaTIP1-1c和TaTIP3-1b参与耐旱的功能和机理研究

Water transport in plant cellular transport is mainly processed by aquaporins. We.identified 105 wheat aquaporins and chose 2 representative TaTIP1-1c and TaTIP3-1b for further studies. We'll assay the tissue-specific expression profiling of the TaTIP1-1c and TaTIP3-1b promoter at different stages of wheat, with or without water stress at booting stage. Meanwhile, for TaTIP1-1c and TaTIP3-1b ectopic-expressed transgenic wheat, we will perform expression analysis of all the selected key aquaporins in leaves, roots, stems and spikes, with or without water stress. The water permeability of all the transformants' protoplasts from leaves and roots will be validated with environmental water stress. And then we'll identify the physiological characters and phenotype of plants from all the treatments. Finally a preliminary functional model for wheat water transport with or without water stress at booting state will be established, with TaPIP1-2 and TaTIP2-3 in the center. This project will also provide agricultural germplasm resources for breeding drought-tolerant wheat.

植物体的水分转运过程主要是由水通道蛋白负责的。我们通过生物信息学手段鉴定到了105个小麦水通道蛋白，从中选取两个关键水通道蛋白TaTIP1-1c和TaTIP3-1b进行研究；在自然状态和施加孕穗期干旱胁迫的小麦的全生长期，我们将对TaTIP1-1c和TaTIP3-1b的表达位置和表达强度进行追踪。在自然状态或干旱胁迫下，对差异表达TaTIP1-1c和TaTIP3-1b的转基因小麦，进行植株的叶片、根部、茎部、穗部中多种关键水通道蛋白基因的表达分析；对转基因植株的叶片和根部原生质体细胞进行干旱胁迫下的透水性检测；最后结合转基因植株的生理表现和表型特点，建立小麦自然状态下和孕穗期干旱胁迫下以TaTIP1-1c和TaTIP3-1b为中心的水通道蛋白转运水分的协同作用模型。本项目也能为农业生产上筛选耐旱小麦品种提供新种质资源。

水通道蛋白是在生物体细胞的膜系统上广泛存在的孔道蛋白，当水通道开放时，膜内外的水分子能够沿着水势由高到低的方向进行跨膜转运。水通道蛋白对于维持小麦根、茎、叶、花器官和种子等发育所需的正常水分生理环境有直接的调控作用。我们选择两个关键水通道蛋白TaTIP1-1c和TaTIP3-1b进行研究，明确了TaTIP1-1c和TaTIP3-1b蛋白在小麦全生长期的组织特异性表达模式；明确了TaTIP1-1c和TaTIP3-1b 对小麦耐旱性的影响；建立了小麦自然状态下和孕穗期干旱胁迫下以TaTIP1-1c和TaTIP3-1b为中心的水通道蛋白协同作用的初步模型。