Ectopic expression of a soybean SVP-like gene in tobacco causes abnormal floral organs and shortens the vegetative phase

MADS-box family transcription factors play critical roles in regulating plant developmental processes. SHORT VEGETATIVE PHASE (SVP), a MADS-box family member, was demonstrated to be a key regulator in floral transition and identity in Arabidopsis thaliana. The present study isolated and characterized two soybean SVP-like genes, GmSVP1 and GmSVP2. A molecular sequence analysis demonstrated that each GmSVP protein contains a typical MADS_MEF2-like domain and a K-box region domain. GmSVPs are closely related to MtSVP and PsSVP but more distantly to AtSVP within the dicot SVP homology sub-clade. Quantitative real-time PCR assays showed intense expression of GmSVPs in floral organs, stamens and pistils during soybean flowering but no expression in soybean developing seeds or in the pod shell. In addition, GmSVP1 responded to abiotic stresses including low temperature and wounding. Ectopic expression of GmSVP1 caused the abnormal development of stamens, petals, and flower buds and slightly accelerated the flowering time in transgenic tobacco plants (Nicotiana tabacum). These results suggested that GmSVP1 acts as a regulator in soybean floral identity and flowering, which may be applied to the industrialization of hybrid soybean.