Arabidopsis CUP-SHAPED COTYLEDON3 regulates postembryonic shoot meristem and organ boundary formation.
Overall shoot architecture in higher plants is highly dependent on the activity of embryonic and axillary shoot meristems, which are produced from the basal adaxial boundaries of cotyledons and leaves, respectively. In Arabidopsis thaliana, redundant functions of the CUP-SHAPED COTYLEDON genes CUC1, CUC2, and CUC3 regulate embryonic shoot meristem formation and cotyledon boundary specification. Their functional importance and relationship in postembryonic development, however, is poorly understood. Here, we performed extensive analyses of the embryonic and postembryonic functions of the three CUC genes using multiple combinations of newly isolated mutant alleles. We found significant roles of CUC2 and CUC3, but not CUC1, in axillary meristem formation and boundary specification of various postembryonic shoot organs, such as leaves, stems, and pedicels. In embryogenesis, all three genes make significant contributions, although CUC3 appears to possess, at least partially, a distinct function from that of CUC1 and CUC2. The function of CUC3 and CUC2 overlaps that of LATERAL SUPPRESSOR, which was previously shown to be required for axillary meristem formation. Our results reveal that redundant but partially distinct functions of CUC1, CUC2, and CUC3 are responsible for shoot organ boundary and meristem formation throughout the life cycle in Arabidopsis.
Hibara
Ken-ichiro
K
Graduate School of Biological Sciences, Nara Institute of Science and Technology, Nara 630-0192, Japan.
Karim
Md Rezaul
MR
Takada
Shinobu
S
Taoka
Ken-ichiro
K
Furutani
Masahiko
M
Aida
Mitsuhiro
M
Tasaka
Masao
M
D000483:Alleles; D017360:Arabidopsis / Q000166:cytology / Q000196:embryology / Q000254:growth & development*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D047108:Embryonic Development; D004742:Enhancer Elements, Genetic / Q000235:genetics; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D018519:Meristem / Q000166:cytology / Q000196:embryology / Q000254:growth & development*; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D010641:Phenotype; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D036226:Seedlings / Q000166:cytology; D012639:Seeds / Q000166:cytology; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
D029681:Arabidopsis Proteins; C107294:CUC2 protein, Arabidopsis; C478975:CUC3 protein, Arabidopsis; C474737:LAS protein, Arabidopsis; D012333:RNA, Messenger; D014157:Transcription Factors