Plant aquaporins: Their roles beyond water transport

Compared to other organisms, plants have evolved a greater number of aquaporins with diverse substrates and functions to adapt to ever-changing environmental and internal stimuli for growth and development. Although aquaporins were initially identified as channels that allow water molecules to cross biological membranes, progress has been made in identifying various novel permeable substrates. Many studies have characterized the versatile physiological and biophysical functions of plant aquaporins. Here, we review the recent reports that highlight aquaporin-facilitated regulation of major physiological processes and stress tolerance throughout plant life cycles as well as the potential prospects and possibilities of applying aquaporins to improve agricultural productivity, food quality, environmental protection, and ecological conservation.