抄録
Plants are sensitive to changes in their ambient environment and respond to these to determine the optimal timing of the floral transition. Under shade or high density of vegetation, plants positively change their morphology to compete for sunlight, by for example elongating their stems and leaves. Acceleration of flowering is also a typical shade avoidance response. Detection of changes in light quality is a major signal in responding to the surrounding shade condition. Plant leaves absorb red light, whereas far-red light is transmitted or reflected. Therefore the R:FR ratio of shady conditions is lower than that of unfiltered sunlight. This change of light quality is perceived by phytochrome, and particularly phyB represses the shade response. We showed previously that inactivation of phyB by mutation stabilizes CONSTANS (CO) protein, a transcription factor that promotes early flowering. This suggests that stabilization of CO in shade could be responsible for the observed early flowering. We are interested in the mechanism by which phyB and CO functions promote early flowering in shade and are using a combination of biochemical and genetic approaches to address these issues.
