Chapter 25 - The role of aquaporins during plant abiotic stress responses

Abstract

Aquaporins (AQPs) are crucial transporters in the plant cells, which mobilize the intercellular passage of water, solvent, and dissolved solutes from the source to the sink. Thus these transmembrane channel proteins are effective checkpoints of solvent transport across tissues. It is known that cellular water conservation is the major strategy for plant tolerance against multiple abiotic stresses, such as salinity, drought, desiccation, temperature, nutrient limitation, and heavy-metal toxicity. Hence, the roles of AQPs in abiotic stress tolerance are obvious. Transgenic plants overexpressing AQP genes have shown tolerance toward suboptimal environmental conditions. The basic mechanism behind such tolerance phenotype is efficient stomatal closure, low rate of water loss, and effective water circulation throughout the system. Among the different subclasses of AQPs, the plasma-membrane intrinsic proteins are involved in diverse stress responses. Thus these transporters have been highlighted as potential molecular targets, which can be expressed to generate multiple stress tolerance. This chapter exhaustively discusses the diverse roles of AQPs in promoting plant survival under challenging environmental situations.