Abstract
In higher plants, a phototropic response is induced by unilateral blue-light (BL) irradiation in a phototropin (phot)-photoreceptors-dependent manner. Other photoreceptors, phytochromes (phys) and cryptochromes (crys), also modulate phototropism. Hypotheses for function of phys and crys in hypocotyl phototropism include a suppression of hypocotyl gravitropism and/or a control of phytohormone metabolism, but those precise roles are still unknown. Recent studies have indicated that phys and crys regulate function of phototropin signaling factors and auxin metabolism and transport, suggesting that phys and crys play more important roles than we expected in the phototropic responses. In fact, our recent analysis using a multiple mutant supports this idea. In this talk, I will introduce recent studies indicating the crosstalk among photoreceptor signaling pathways in phototropism, and a recent hypothetical model of the phototropic response in Arabidopsis.
