BACKGROUND Transcription factors of the RAV (RELATED TO ABI3 AND VP1) family are plant-specific and possess two DNA-binding domains. In Arabidopsis thaliana, the family comprises six members, including TEMPRANILLO 1 (TEM1) and TEM2. Arabidopsis RAV1 and TEM1 have been shown to bind bipartite DNA sequences, with the consensus motif C(A/C/G)ACA(N)2-8(C/A/T)ACCTG. Through direct binding to DNA, RA...

Phytochromes are primary photoreceptors mediating diverse responses ranging from induction of germination to floral induction in higher plants. We have isolated novel recessive rep1 (reduced phytochrome signaling 1) mutants, which exhibit a long-hypocotyl phenotype only under far-red light but not under red light. Physiological characterization showed that rep1 mutations greatly reduced a subse...

In flowering plants, the founder cells from which reproductive organs form reside in structures called floral meristems. Recent molecular genetic studies have revealed that the specification of floral meristems is tightly controlled by regulatory networks that underpin several coordinated programmes, from the integration of flowering signals to floral organ formation. A notable feature of certa...

Day length controls flowering time in many plants. The day-length signal is perceived in the leaf, but how this signal is transduced to the shoot apex, where floral initiation occurs, is not known. In Arabidopsis, the day-length response depends on the induction of the FLOWERING LOCUS T (FT) gene. We show here that local induction of FT in a single Arabidopsis leaf is sufficient to trigger flow...

What is the flowering transition? It marks the end of vegetative growth and the beginning of reproductive development in flowering plants. The physiological changes that cause it are referred to as floral induction. What is SAM? The shoot apical meristem — a group of undifferentiated progenitor cells that occupies the tip of the stem. It gives rise to both vegetative organs (leaves) and reprodu...

Plants produce new appendages reiteratively from groups of stem cells called shoot apical meristems. LEAFY (LFY) and APETALA1 (AP1) are pivotal for the switch to the reproductive phase, where instead of leaves the shoot apical meristem produces flowers. Use of steroid-inducible activation of LFY demonstrated that early expression of AP1 is a result of transcriptional induction by LFY. This AP1 ...

A remarkable characteristic of pineapple is its ability to undergo floral induction in response to external ethylene stimulation. However, little information is available regarding the molecular mechanism underlying this process. In this study, the differentially expressed genes (DEGs) in plants exposed to 1.80 mL·L(-1) (T1) or 2.40 mL·L(-1) ethephon (T2) compared with Ct plants (control, clean...

A screen for mutations affecting flower formation was carried out and several filamentous flower (fil) alleles were identified. In fil mutants, floral primordia occasionally give rise to pedicels lacking flowers at their ends. This defect is dramatically enhanced in fil rev double mutants, in which every floral primordium produces a flowerless pedicel. These data suggest that the FIL and REV ge...