Grasses have top-notch border control to conserve water in their leaves. Now, scientists have identified the genetic switch that makes them such masters at taking in carbon dioxide without losing water. The find might eventually help scientists create more drought-resistant crop plants, the researchers report in the March 17 Science.
Adjustable pores called stomata on the undersides of leaves help plants take in CO2 while minimizing water loss. Like pupils responding to sunlight, plants open and close their stomata in response to changing light, humidity and temperature. Grass stomata can open wider and respond more quickly than those in other plants, which helps grasses photosynthesize more efficiently.