Abstract: The fate of the flowering signal integrators is determined by SHORT VEGETATIVE PHASE（SVP）and FLOWERING LOCUS C（FLC）. For further study on the mechanism of the mutual recognition between SVP and FLC in Brassica juncea Coss.（Mustard） variety‘QJ’，the coding sequences of SVP and FLC with digestion sites of EcoRⅠ/BamHⅠwere respectively amplified via PCR，and the interactions between SVP and FLC were detected by the yeast two-hybrid system. The full-length FLC was fused to the GAL4 DNA activation domain，which was designated as pGADT7FLC and then transformed into Y187 yeast stain. While SVP was fused to the GAL4 DNA binding domain，which was designated as pGBKT7SVP and then transformed into Y2HGold yeast stain. The two transformed yeast stains did not exhibit autoactivation and toxicity. The yeast stains of pGADT7FLC and pGBKT7SVPcouldmate into yeast diploids. The zygote diploids grew on selective agar plates QDO/X/A （SD/-Ade/-His/-Leu/-Trp/X-α-Gal/AbA）with blue stains. The results strongly indicated that SVP and FLC could combine with each other. Furthermore，the expression vectors of bait plasmid（pGBKT7SVP）and prey plasmid（pGADT7FLC）were exchanged with each other. Then the recombinated yeast plasmids of pGADT7SVP and pGBKT7FLC were reconstructed and respectively transformed into Y187 and Y2HGold yeast stains. The yeast zygote diploids（pGADT7SVP × pGBKT7FLC）exhibit on selective agar plates QDO/X/A，and the DNA-BD and AD were brought into proximitry to activate transcription of four independent reporter genes（AUR1-C，HIS3，ADE2，MEL1）. The results showed that SVP and FLC could act with each other to combine and form a complex.

Key words: Brassica juncea, SVP, FLC, yeast two-hybrid system