Plants wage war with each other to outgrow and absorb sunlight! If a plant is shaded by another, it becomes cut off from essential sunlight it needs to survive. To escape this deadly shade, plants have special light sensors that can detect depletion of red and blue light - wavelengths absorbed by vegetation - and can set off an internal alarm when threatened by the shade of other plants.
These sensors can distinguish between an aggressive nearby plant from a passing cloud. Scientists at the Salk Institute in the US have discovered a way by which plants assess the quality of shade to outgrow menacing neighbors - a finding that could be used to improve the productivity of crops.
The new work shows how the depletion of blue light detected by molecular sensors in plants triggers accelerated growth to overcome a competing plant.
It was known that plants respond to diminished red light by activating a growth hormone called auxin to outpace its neighbors. However, this is the first time researchers have shown that shade avoidance can happen through an entirely different mechanism - instead of changing the levels of auxin, a cellular sensor called cryptochrome responds to diminished blue light by turning on genes that promote cell growth.
This revelation could help researchers learn how to modify plant genes to optimize growth to grow more aggressively and give a greater yield even in a crowded, shady field.
The findings appeared in the Cell.