Mutants of Circadian-Associated PRR Genes Display a Novel and Visible Phenotype as to Light Responses during De-Etiolation of Arabidopsis thaliana Seedlings

Abstract

In Arabidopsis thaliana, it is currently accepted that certain mutants with lesions in clock-associated genes commonly display hallmarked phenotypes with regard to three characteristic biological events: (i) altered rhythmic expression of circadian-controlled genes, (ii) changes in flowering time, and (iii) altered sensitivity to red light in elongation of hypocotyls. During the course of examination of the clock-associated mutants of PSEUDO-RESPONSE REGULATORS, PRRs, including TOC1 (PRR1), we found that they commonly show another visible phenotype of anomalous greening responses upon the onset to light exposure of etiolated seedlings. These findings are indicative of a novel link between circadian rhythms and chloroplast development.