The shade avoidance syndrome: multiple responses mediated by multiple phytochromes

ABSTRACT In recent years, the concept of shade avoidance has provided a functional meaning to the role of the phytochrome photoreceptor family in mature plants in their natural environment, and the question of which of these phytochromes is responsible for shade avoidance reactions has inevitably been raised. Unfortunately, a misconception has arisen that phytochrome B is solely responsible for detecting the environmental signal that initiates the shade avoidance syndrome. This view is too simplistic, and is based upon a selective interpretation of the available evidence. In this short Commentary, we review the concept of the shade avoidance syndrome, show how the misconception arose, and emphasize the plurality of perception and response that is crucial to successful competition for light.