Poster: Stomatal Physiology

Abs # 386: Leaf Movement Induced by Blue Light in the Model Legume, Lotus japonicus

Presenter:	Inada, Sayaka , sainada@psc.riken.go.jp
Authors	Inada, Sayaka  (A)   Takahashi, Mihoko  (A)   Okada, Kiyotaka  (A) (B)  Sakai, Tatsuya  (A)
Affiliations:	(A): RIKEN, Plant Science Center (B): Graduate School of Science, Kyoto University

Blue light induces leaf (or leaflet) movement in leguminous plants. Physiological and biochemical studies have demonstrated that the movement is carried out through the volume changes of pulvinar motor cells. However, the molecular mechanism of blue-light induced leaf movement has remained unknown. To know the above-mentioned mechanism, we have screened mutants from model legume plant, Lotus japonicus and obtained a slow leaf-movement to blue-light irradiation mutant, laziness. Leaf opening was rapidly induced by blue-light irradiation, but not by red-light irradiation. In laziness mutant, the leaves did not open half as much movement as wild-type plant under blue-light irradiation. However, nictinasty of the laziness mutant was similar to that of the wild-type plant, and the other blue-light responses, hypocotyl phototropism, chloroplast relocation and inhibition of hypocotyl elongation, were also normal. To identify the LAZINESS locus, we are performing a map-based cloning. In addition, we isolated Lotus CRYPTOCHROMEs and PHOTOTROPINs, which loci encode blue-light receptors in Arabidopsis, and generated transgenic plants expressing anti-sense gene to analysis the function of blue-light receptors in Lotus. Blue-light responses of the transformants will be reported.