title: Characterization of shade avoidance responses in Lotus japonicus.
abstract: Sessile plants must continuously adjust their growth and development to optimize photosynthetic activity under ever-fluctuating light conditions. Among such light responses in plants, one of the best-characterized events is the so-called shade avoidance, for which a low ratio of the red (R):far-red (FR) light intensities is the most prominent stimulus. Such shade avoidance responses enable plants to overtop their neighbors, thereby enhancing fitness and competitiveness in their natural habitat. Considerable progress has been achieved during the last decade in understanding the molecular mechanisms underlying the shade avoidance responses in the model rosette plant, Arabidopsis thaliana. We characterize here the fundamental aspects of the shade avoidance responses in the model legume, Lotus japonicus, based on the fact that its phyllotaxis (or morphological architecture) is quite different from that of A. thaliana. It was found that L. japonicus displays the characteristic shade avoidance syndrome (SAS) under defined laboratory conditions (a low R:FR ratio, low light intensity, and low blue light intensity) that mimic the natural canopy. In particular, the outgrowth of axillary buds (i.e., both aerial and cotyledonary shoot branching) was severely inhibited in L. japonicus grown in the shade. These results are discussed with special emphasis on the unique aspects of SAS observed with this legume.
authors: Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan. hnakanis@agr.nagoya-u.ac.jp
authors: Hanayo
authors: H
authors: Ueoka-Nakanishi
authors: Nanako
authors: N
authors: Hori
authors: Kai
authors: K
authors: Ishida
authors: Natsuko
authors: N
authors: Ono
authors: Takafumi
authors: T
authors: Yamashino
authors: Norihito
authors: N
authors: Nakamichi
authors: Takeshi
authors: T
authors: Mizuno
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development; D029681:Arabidopsis Proteins / Q000235:genetics / Q000502:physiology; D003624:Darkness; D018398:Homeodomain Proteins / Q000235:genetics / Q000502:physiology; D008027:Light; D000070116:Lotus / Q000235:genetics / Q000254:growth & development*; D008969:Molecular Sequence Data; D010788:Photosynthesis / Q000235:genetics; D018524:Phototropism; D018515:Plant Leaves / Q000235:genetics / Q000254:growth & development; D017386:Sequence Homology, Amino Acid
chemical_list: C523746:ATHB23 protein, Arabidopsis; D029681:Arabidopsis Proteins; D018398:Homeodomain Proteins