Abstract: [Objective] This project aims to construct a bait vector for yeast two-hybrid system of TA gene in Acidovorax citrulli in order to lay the foundation for exploring the gene function involved in the pathogenic mechanism.[Method]The TA gene was amplified by PCR and cloned into the vector pGBKT7.The verified pGBKT7-TA was then transformed into the yeast strain AH109.The activities of report genes ADE2,HIS3 and LacZ were used to detect the self activation of pGBKT7-TA,and the toxicity of pGBKT7-TA was investigated in nutrient deficient medium.[Result]The constructed bait vector pGBKT7-TA had neither self-activation nor toxic effect in the yeast strain AH109.[Conclusion]The constructed bait vector can be used for the follow-up work of the yeast two hybrid system,which has laid a foundation for further screening of proteins interacting with TA from the cDNA library of cucumber cotyledons infected by Acidovorax citrulli.