Abstract
Cryptochromes (CRYs) are blue-light receptors found in both plants and animals. In Arabidopsis, CRY1 and CRY2 are major blue-light receptors known to regulate flowering time. We had previously isolated PnCRY1 (Pharbitis nil Cryptochrome 1) whose transcripts transiently increased during the 16-h flower inductive dark period. In this study, we cloned P. nil homolog of CRY2 (PnCRY2), which encoded a putative polypeptide of 653 amino acids with a molecular mass of 74 kD. The deduced amino acid sequence of PnCRY2 showed 72% and 67% amino acid identity with those of tomato and Arabidopsis, respectively. PnCRY2 expression showed circadian rhythm both under continuous dark (DD), and continuous light conditions (LL). We will show the results of its expression analysis in various conditions (different photoperiodic conditions, effects of exposure to blue and red light, etc), and discuss the participation of PnCRYs in the photoperiodic induction of flowering in P. nil.
