Abstract
An embryonic shoot apical meristem (SAM) formed in embryo constructs a main shoot after germination and axillary shoot meristems formed in each leaf axils develop lateral shoots. These meristems are essential for the development of shoot architecture.
CUC1 and CUC2 were identified as factors regulating SAM formation during embryogenesis. We have isolated CUC3 (CUP-SHAPED COTYLEDON3) from screening of cuc2 enhancer mutants. CUC3 have a highly conserved NAC domain comparable with CUC1, 2.
cuc3 single mutant exhibited an abnormal shoot, lateral shoots occasionally uncoupled from cauline leaf and there is no axillary shoot meristem at a low frequency. In addition, cuc2 mutation enhanced the shoot phenotypes of cuc3. However, mutation of CUC1 didn't enhance cuc3 in aerial part. These indicated that CUC2 and CUC3 act redundantly to regulate axillary meristem formation post-embryonically.
