Plants’ ability to sense red light key to life on land
(July 28, 2015) The light-sensing molecules that tell plants whether to germinate, when to flower and which direction to grow were inherited millions of years ago from ancient algae, finds a new study from Duke University.
The findings are some of the strongest evidence yet refuting the prevailing idea that the ancestors of early plants got the red light sensors that helped them move from water to land by engulfing light-sensing bacteria, the researchers say.
The results appear online in Nature Communications.
“Much like we see the world through our eyes, plants ‘see’ the world through light-sensitive proteins in their leaves called photoreceptors,” said Duke postdoctoral researcher Fay-Wei Li.
Photoreceptors monitor changes in the direction, intensity, duration and wavelength of light shining on a plant, and send signals that tell plants when to sprout, when to blossom, and how to bend or stretch to avoid being shaded by their neighbors.
“Light is what gives plants the energy they need to survive,” Li said. “But light is constantly changing with the time of day and the seasons and the surrounding vegetation. Photoreceptors help plants determine if it’s summer or winter, or if they’re under the canopy or out in the open.”