Abstract: In order to clarify the protein interaction mechanisms of flowering promoting factor AGL19 with another two floral integrator factors（AGL24 and SOC1）in flowering pathways，AGL19，AGL24 and SOC1 genes were cloned from Brassica oleracea var. italica，and encoded 221，221 and 214 amino acids，respectively. AGL19，AGL24 and SOC1 were MIKC-type proteins and similar to Brassica oleracea，B. rapa and Chinese cabbage. AGL19 and SOC1 were members of TM3/SOC1 subfamily. Yeast two-hybrid assays showed that the fused strains could grew with blue colonies on QDO/X/A plates，indicating that AGL19 interact with AGL24 and activated the expression of the reporter genes AUR1-C，HIS3，ADE2 and MEL1. However，AGL19 could not interact with SOC1. These results suggested that AGL24 not SOC1 was the direct target protein of AGL19. Additionally，SOC1 also could interact with the AGL24，suggesting that AGL19 can indirectly interact with SOC1 through AGL24.

Key words: Brassica oleracea var. italica, AGL19, SOC1, AGL24, protein interaction, flowering regulation