SDR6 is involved in regulation of flowering time in Arabidopsis thaliana

Identification of flowering-time related genes in Arabidopsis thaliana has very important and meaningful to understand the regulation mechanism of the flowering-time. One late flowering mutant plant which displays a delayed transition to flowering was obtained from the Arabidopsis T-DNA insertion mutant library. SDR6, which encodes a short-chain dehydrogenase/reductase containing a NAD(P)-binding domain in Arabidopsis, has been identified as a novel flowering-time gene in Arabidopsis by further analyzing of SDR6 complementing plants. The sdr6 plants displayed later flowering than wild-type plants both in long and short days, but flowered later in short day than in long day. The flowering-time of SDR6 complementing plants is similar to that of wild-type plants. The late-flowering phenotype of sdr6 plants was reversed by gibberellin and vernalization treatments, which is similar to those of several mutants in the autonomous pathway. Compared with the wild-type, expression levels of FLC, LD, FVE, and SOC1 genes, key components of the autonomous pathway, were significantly altered in sdr6 mutants. However, expression levels of the key genes in the photoperiod, gibberellin, and vernalization pathways were not obviously different. Therefore, this gene may be involved in the autonomous flowering pathway to regulate the Arabidopsis flowering.