Interactions between flowering time genes and Sepallata4 modulate Leafy expression.

• Main Author: Lee, Shu Qing.
• Other Authors: School of Biological Sciences
• Format: Final Year Project
• Language: English
• Published: 2011
• Subjects: DRNTU::Science::Biological sciences::Botany::Plant physiology
• Online Access: http://hdl.handle.net/10356/45112
• Institution: Nanyang Technological University

In Arabidopsis thaliana, the initiation of flower development requires robust expression of floral meristem identity gene, LEAFY (LFY). During flower development, the floral patterning is regulated by the flowering time genes, as well as coordinated activities of four classes of homeotic genes, explained by the ABCE model. The class-E SEPALLATA (SEP) genes are redundantly required with the other three classes of homeotic genes to specify all four floral organ. In this study, we showed that three flowering time genes, SUPPRESSOR OF OVEREXPRESSION OF CONSTANS 1 (SOC1), SHORT VEGETATIVE PHASE (SVP), and AGAMOUS-LIKE 24 (AGL24), together with SEP4, are redundantly required for maintaining floral meristem identity. In the quadruple mutant soc1-2 svp-41 agl24-3 sep4-1, floral organs were transformed into leaf-like structures, a phenomenon known as floral reversion. Subsequently, LFY mRNA in situ hybridisation at the meristems of quadruple mutant revealed that LFY is only transiently expressed in early flowering stages. With LFY highly involved in the floral determinacy and development, this resultant transient LFY expression may be the cause of floral reversion. Nevertheless, the activities of the three flowering time genes and SEP4 are required to maintain high LFY expression in the flower bud and to prevent floral reversion.