Some biologists hypothesize that a plant will stop growing if it's in the shade of another plant, a reaction that's triggered when it senses an unusual ratio of red light to far-red light.

一些生物学家假设，如果一株植物处在另一株植物的荫蔽下，它就会停止生长，当它感知到红光与远红光的不寻常比例时，反应就会触发。