Molecular Cloning and Expression Pattern of SVP Gene Influencing Flowering Time in Brassica napus and Brassica juncea
Mutiple homologs of short vegetative phase (SVP) were isolated from inflorescences of allotetraploid rapeseed cultivars Xiangyou No. 15 (Brassica napus L. ) and Sichuan Yellow-seeded (Brassica juncea L. ) by using homologous cloning and reverse transcription PCR technology, which was designated BnSVP-1 ,BnSVP-2 ,BnSVP-3, BnSVP-4,BnSVP-5 and BjSVP-1 ,BjSVP-2 ,BjSVP-3, respectively. All these sequences have been deposited in Gen-Bank with accession number JQ906717 , JQ906718 , JQ906719, JQ906720, JQ316471 and JQ906715 , JQ906716, JQ316472 respectively. Results of sequence analysis showed that each homolog was 726 bp and encoded 241 amino acids with typical M,I,K and C domain of MADS-box gene. The SVP expression pattern of Xiangyou No. 15 after been treated with photoperiod, GA3 spraying and vernalization was studied, the results demonstrated that different photoperiods and GA3 spraying could change its expression in the stem or root,but vernalization did not. The expression change would result in early flowering. In rapeseed, SVP expressed in root, stem and leaf tissues in vegetable phase,but after transition to reproductive phase its expression limited only in floral organ such as stamen,pistil and sepal, no expression was detected in petal. SVP also expressed in young siliques,while more in silique hull than in seed.