Gravity Sensing, Interpretation, and Response

Abstract

Because higher plants spend their sessile lives at the site of their germination, they rely on a number of strategies to ensure their survival in response to environmental stimuli. One of the stimuli to which plants can respond is gravity. Here, we describe recent findings with regard to the plant’s response to gravity. We put specific emphasis on the molecular mechanism of gravitropism, which is a well-studied response to gravity. Since the direction and the magnitude of gravity are relatively constant on the surface of the Earth, gravitropism can be regarded as a posture adjustment, triggered by sensing the tilt of organs relative to the direction of gravity. Recent studies that combined molecular genetics and cell biological approaches in Arabidopsis thaliana have contributed to understand the mechanism of gravitropism.