Genetic Screen Identifying Mutations Which Suppress the Phenotype of a Red Light Hypersensitive Mutant

Abstract

A plant's ability to assess light quantity and quality is fundamental to maintaining healthy growth. One way that plants sense changing light conditions is via the perception of red (R~660 nm) and far red (FR~730 nm) wavelengths by a group of light receptors called the phytochromes (PHYs). This study found that that two highly similar genes Light Response BTB1 (LRB1) and Light Response BTB2 (LRB2) have a role in the red light-response pathway in Arabidopsis. Plants with disruptions of these two genes are red light hypersensitive and thus display enhanced de-etiolation in response to red light and significant shade tolerance. In order to identify the component(s) of the red light signaling pathway that the LRBs are regulating (or other actors in the pathway) this study conducted a genetic suppressor/enhancer screen, identifying mutations which relieve or increase red light inhibition of hypocotyl elongation in the lrb1/lrb2 red hypersensitive double mutants.