A Plant's Dilemma

Plants absorb water through their roots, then expel it through pores (stomata) in their leaves. In their Perspective, Grill and Ziegler explain that in times of drought, closing the stomata can help a plant conserve water. Thus, the finding in this week's issue by [ Pei et al .][1] --that mutation of a gene encoding a protein-modifying enzyme can cause a plant to close its stomata more easily--may point the way to limitation of water loss by plants, a tremendous economic benefit in arid regions. [1]: http://www.sciencemag.org/cgi/content/short/282/5387/287