Objectives: To unravel the role of TDC1 gene in the resistance of Aegilops varabilis NO.1 to the root knot nematode and understand the mechanism of Aegilops varabilis NO.1 resistance in cereal cyst nematodes and root knot nematodes; Methods: Expression vectors containing AeVTDC1 was constructed andused for transformation of tobacco(Nicotiana tabacum)by agrobacteria.Transgenic positive plants were selected by PCR with specific primers and southern blot.To test resistance to root-knot nematode,transgenic and wild-type tobaccos were cultivated in soil with root-knot nematodes.HPLC-MS analysis was used to measure the level of tryptamine in roots ofAeVTDC1transgenic tobacco.Results: 6 AeVTDC1 transgenic tobaccos have been obtained through PCR and southern blot tests.Tobacco containingAeVTDC1 showed more resistant to root knot nematodes than wild type.HPLC-MS analysis of tryptaminewere operated in transgenic and wild-type tobaccos,and the results showed the level of tryptamine in transgenic tobaccos was much higher than that of wild-type tobaccos.Conclusions:In this study,preliminary results indicated that TDC play a positive role in resistance to root knot nematodes in Aegilops varabilis No.1.And overexpression of AeVTDC1 increased the accumulation of tryptamine.To clearly clarify the role of AeVTDC1 and its mechanism,further analysis were underway.