SRA

Polycarpic perennials maintain vegetative growth after ?owering. PERPETUAL FLOWERING 1 (PEP1), the orthologue of FLOWERING LOCUS C (FLC) inArabis alpina regulates ?owering and contributes to polycarpy in a vernalisation-dependent pathway. pep1 mutants do not require vernalisation to ?ower and have reduced return to vegetative growth as all of their axillary branches become reproductive. To identify additional genes that regulate ?owering and contribute to perennial traits we performed an enhancer screen of pep1. Using mapping-by-sequencing, we cloned a mutant (enhancer of pep1-055, eop055), performed transcriptome analysis and physiologically characterised the role it plays on perennial traits in an introgression line carrying the eop055 mutation and a functional PEP1 wild-type allele. eop055 ?owers earlier than pep1 and carries a lesion in the A. alpina orthologue of the APETALA2 (AP2)-like gene, TARGET OF EAT2 (AaTOE2). AaTOE2 is a ?oral repressor and acts upstream of SQUAMOSA PROMOTER-BINDING PROTEIN-LIKE 5 (AaSPL5). In the wild-type background, which requires cold treatment to ?ower, AaTOE2 regulates the age-dependent response to vernalisation. In addition, AaTOE2 ensures the maintenance of vegetative growth by delaying axillary meristem initiation and repressing ?owering of axillary buds before and during cold exposure. We conclude that AaTOE2 is instrumental in ?ne tuning different developmental traits in the perennial life cycle of A. alpina. Overall design: Main shoot apices from 8-week-old plants vernalized for eight weeks (8wLD+8wV) were collected from wild-type and Aatoe2_IL plants to study the effect of AaTOE2 at the transcriptomic level in the regulation of flowering during vernalization. Also, V3 buds were harvested from 8-week-old plants vernalized for eight weeks from both genotypes to study the role of AaTOE2 in the development of axillary branches.