During the production of flowers in Arabidopsis thaliana many key decisions are taken in a short lapse of time. The floral primordium has to be positioned correctly on the inflorescence meristem and it has to grow to the required dimension before flower organs are themselves positioned and differentiate.
All these tasks are strictly controlled at a molecular level and the genetic networks that underlies them have been intensively studied in the last 30 years. Nevertheless we are far from having a comprehensive knowledge on this process and the genetic mechanism controlling the arise, identity of the floral primordium and the timing of its developmental phases are widely unknown.
We have identified new genes potentially involved in early flower development with two approaches: (i) Analysis of the specific transcriptome of the earliest stages of flower development and (ii) Co-expression analysis using APETALA1 and LEAFY, two genes that determine the identity of the floral meristem, which is the earliest stage of flower development. We have observed that multiple REM transcription factors are co-expressed with APETALA1 and LEAFY.
Characterizing insertional mutants for genes potentially involved in early flower development and REM transcription factors, we have rarely observed a phenotype in the stages under study. This is consistent with the hypothesis that genes controlling early flower development are often functionally redundant. We are implementing various methods to overcome functional redundancy implementing analysis of gene families, multiple RNA interference and gene targeting strategies
