Maria Albani - Arabis alpina as a model to study flowering and perennial traits

A. alpina is a Brassicaceae species and perennial relative of the annual model Arabidopsis thaliana. Comparative studies between these two models have been successful in tracing at the molecular level the mechanisms that contributed to the diversification of the annual and perennial life strategies. Differences in flowering behavior between annual and perennial species contribute to differences in their life strategy. A text book example is the role of FLOWERING LOCUS (FLC) in life history evolution of A. alpina and A. thaliana. FLOWERING LOCUS C (FLC) is a key floral repressor in A. thaliana that regulates flowering in response to vernalisation. Its orthologue in A. alpina, PERPETUAL FLOWERING 1 (PEP1) also ensures flowering in response to vernalisation but in addition contributes to perennial traits such as polycarpic growth habit and the duration of the flowering episode. pep1 mutants flower without vernalisation and show reduced return to vegetative growth. My group is studying the regulation of inflorescence development and outgrowth in perennials using A. alpina as a model. We performed an enhancer screen of the pep1-1 mutant and isolated several second-site mutants that show inflorescence phenotypes. Mapping by sequencing of several mutants reveal a novel regulator not previously studied in A. thaliana.