Individual and combinatorial activities of SHORT VEGETATIVE PHASE and FLOWERING LOCUS C define distinct modes of flowering regulation in Arabidopsis

MATEOS, JULIETA LISA

Mar del Plata

Congreso; XV Congreso Latinoamericano de Fisiología Vegetal ? XXX Reunión Argentina de Fisiología Vegetal; 2014

Gene expression is regulated by combinations of transcription factors. Here we study two such plant proteins that combine in a complex to repress expression of genes that trigger flowering. These transcription factors occupy a central position in the regulatory network that confers seasonal patterns of flowering and their activities vary in natural populations contributing to adaptation. By analysing their effects on gene expression and their binding sites across the whole genome in different genetic backgrounds we describe how their activities change when they act individually or as a complex. We show that the complex recognises a set of genes that is not bound by either transcription factor acting alone, and that among these genes those regulating flowering and environmental responses are enriched. In addition, we find that one of the transcription factors, FLOWERING LOCUS C, increases the binding strength of the other, SHORT VEGETATIVE PHASE. Our results describe the genome-wide interdependency of these two transcription factors that have crucial roles in flowering control. We also discuss how their overlapping activities allow plants in natural populations to tolerate genetic variation at these two genes, and thereby contribute to phenotypic differences in seasonal flowering behaviour observed in nature.