title: Clock-controlled and FLOWERING LOCUS T (FT)-dependent photoperiodic pathway in Lotus japonicus I: verification of the flowering-associated function of an FT homolog.
abstract: During the last decade, significant research progress in the study of Arabidopsis thaliana has been made in defining the molecular mechanism by which the plant circadian clock regulates flowering time in response to changes in photoperiod. It is generally accepted that the clock-controlled CONSTANS (CO)-FLOWERING LOCUS T (FT)-mediated external coincidence mechanism underlying the photoperiodic control of flowering time is conserved in higher plants, including A. thaliana and Oryza sativa. However, it is also assumed that the mechanism differs considerably in detail among species. Here we characterized the clock-controlled CO-FT pathway in Lotus japonicus (a model legume) in comparison with that of A. thaliana. L. japonicus has at least one FT orthologous gene (named LjFTa), which is induced specifically in long-days and complements the mutational lesion of the A. thaliana FT gene. However, it was speculated that this legume might lack the upstream positive regulator CO. By employing L. japonicus phyB mutant plants, we showed that the photoreceptor mutant displays a phenotype of early flowering due to enhanced expression of LjFTa, suggesting that LjFTa is invovled in the promotion of flowering in L. japonicus. These results are discussed in the context of current knowledge of the flowering in crop legumes such as soybean and garden pea.
authors.affiliation: Laboratory of Molecular and Functional Genomics, School of Agriculture, Nagoya University, Nagoya, Japan. yamasino@agr.nagoya-u.ac.jp
authors.forename: Takafumi
authors.initials: T
authors.lastname: Yamashino
authors.forename: Saori
authors.initials: S
authors.lastname: Yamawaki
authors.forename: Emi
authors.initials: E
authors.lastname: Hagui
authors.forename: Hanayo
authors.initials: H
authors.lastname: Ueoka-Nakanishi
authors.forename: Norihito
authors.initials: N
authors.lastname: Nakamichi
authors.forename: Shogo
authors.initials: S
authors.lastname: Ito
authors.forename: Takeshi
authors.initials: T
authors.lastname: Mizuno
mesh_terms: D057906:Circadian Clocks / Q000528:radiation effects; D018556:Crops, Agricultural; D035264:Flowers / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism / Q000502:physiology; D018506:Gene Expression Regulation, Plant / Q000528:radiation effects; D000070116:Lotus / Q000235:genetics / Q000254:growth & development / Q000378:metabolism* / Q000502:physiology; D017440:Photoperiod; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D012689:Sequence Homology, Nucleic Acid
chemical_list: D010940:Plant Proteins