Abstract
Phytochrome B (phyB) is a major plant photoreceptor and its polypeptide is folded into two domains: the N-terminal photosensory domain and the C-terminal domain which has been widely believed to be a signaling domain of phyB. However, we have recently demonstrated that the N-terminal domain, but not the C-terminal domain, of Arabidopsis phyB transduces the signal to downstream components, which forces us to reconsider our view on phyB signal transduction. In order to efficiently identify downstream components of the N-terminal domain of phyB by a forward genetics approach, we conceived and established a novel mutant screening method in which several challenging attempts were made to exaggerate the mutant phenotype to a maximum extent and thus to overcome the problem of redundancy of gene function. Here we will describe the details of the strategy and will report on the progress of the mutant screening.
