Phenotype Characterization of Irb Mutants in Arabidopsis thaliana

Abstract

This mutant analysis showed that LRB1 and LRB2 play a role in the regulation of the phytochrome-mediated red light signaling pathway, however whether there is a role in this pathway for the third family member LRB3 in this pathway was unclear. Irb1/Irb2 double mutants display hypersensitivity to red light. We created a number of different Arabidopsis mutants containing various combinations of Irb and phy (phytochrome photoreceptor) mutations in order to determine the relative contributions of the LRB genes to red light signaling and to determine which phytochromes they act downstream of.