干旱胁迫是严重影响全球作物生产的非生物胁迫之一,研究植物耐旱机制已成为一个重要领域.水通道蛋白是一类特异、高效转运水及其它小分子底物的膜通道蛋白,在植物中具有丰富的亚型,参与调节植物的水分吸收和运输.近10年来,水通道蛋白在植物不同生理过程中的作用,一直受到研究人员的关注,特别是在非生物胁迫方面,而研究表明水通道蛋白在干旱胁迫下对植物的耐旱性起着至关重要的作用,能维持细胞水分稳态和调控环境胁迫快速响应.水通道蛋白在植物耐旱过程中的调控机制及功能较复杂,而关于其应答机制和不同亚型功能性研究的报道甚少.该文综述了植物水通道蛋白的分类、结构、表达调控和活性调节,分别从植物水通道蛋白响应干旱表达调控机制、水通道蛋白基因表达的时空特异性、水通道蛋白基因的表达与蛋白丰度,水通道蛋白基因的耐旱转化四个方面阐明干旱胁迫下植物水通道蛋白的表达,重点阐述其参与植物干旱胁迫应答的作用机制,并提出水通道蛋白研究的主要方向.%As the whole growth process of plants is closely related to water conduction in plants,drought stress is one of the abiotic stresses severely affecting global crop production,and it is necessary to study drought tolerance mechanism of plants.Aquaporins(AQPs),major intrinsic proteins(MIPs)present in plasma and intracellular membranes,are ubiq-uitously present in all kingdoms of life,and show their highest diversities in plants. Their roles in facilitating the trans-port of small neutral molecules across cell membranes in higher plants are now well established. Rich in subfamilies, AQPs regulate water absorption and transport in plants and count much in maintaining water balance in plants. During the recent decade,researchers have focused on the role of AQPs in different physiological processes of plants,especially in abiotic stress. According to the previous research, AQPs are critical for drought tolerance of plants under drought stress. The regulation via AQPs is reported as an important way for plants to keep cell water stable and maintain rapid re-sponse to environmental stresses. Numerous studies have identified AQPs as important targets for improving plant per-formance under drought stress. However,the regulation mechanism and function of AQPs are quite complicated in the process of drought tolerance. In addition,the response mechanism and the function of different subfamilies have rarely been reported. In this review,we provide a brief synopsis of the classification,structure,expression and activity regula-tion of AQP superfamily across the green plants.Specifically,the expression of AQPs under drought stress is expounded from the following four aspects:The expression regulation mechanism of response to drought, the temporal and spatial specificity,the gene expression and protein abundance, and the gene transformation for drought tolerance. Numerous studies of plant AQPs under osmotic stress conditions have revealed their importance in regulating plant stress responses. With emphasis placed on the mechanism of AQPs involved in response to drought stress in plants,the author tentatively proposed a main research direction. Responsive mechanism of AQPs in plants exposing to drought stress should be further investigated in the coming exploration to provide scientific supports and molecular materials for applica-tion of AQPs in molecular breeding.
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