Effect of Exogenous ATP on Cold Tolerance of Brassica campestris Seedlings

The effects of exogenous ATP on the cold tolerance of rape seedlings were studied with "Longyou 7" Brassica campestris L.as experimental material.Compared with low temperature stress alone,MDA content and O₂^■ content of rapeseed seedlings were significantly decreased after exogenous ATP pretreatment and low temperature stress,while chlorophyll content and antioxidant enzyme activities（SOD,POD,CAT,APX） were observed.The expressions of RBOHD, RBOHF, CPK4 and CPK5 were increased.Compared with exogenous ATP+low temperature,MDA content was significantly increased under EGTA+exogenous ATP+low temperature treatment.Total chlorophyll content,T-AOC enzyme activity,RBOHD and RBOHF gene expression were all increased.Significantly decreased,MDA content was increased significantly under DMTU+exogenous ATP+low temperature treatment,total chlorophyll content,Ca²⁺-ATPase activity,CPK4,CPK5 gene expression were decreased,indicating that exogenous ATP affected cold tolerance of rape seedlings by Ca²⁺ and H202-dependent mechanisms.