From aquaporin to ecosystem: Plants in the water cycle.

Vascular plants are major intermediaries in the global water cycle, and are highly adapted to both facilitate and resist water fluxes, such as during root uptake, translocation in the xylem, and transpiration by leaves. Here, we summarize the contributions to a Special Issue on water in the Journal of Plant Physiology, which cluster around the theme of control and facilitation of water movement in plants. We conclude with an editorial view of the need for plant physiologists to consider larger cultural issues surrounding water use, especially in terms of the increasing agricultural demand for water to produce animal feed, with its associated trophic nutritive losses and environmental damage.