Abstract: Nitrogen metabolism of Bt transgenic cotton and Bt-CpTI transgenic cotton at seedling stage was studied by pot experiment. The results showed that the characters of nitrogen metabolism in transgenic cotton leaves changed and differed in different transgenic events. In comparing with non-transgenic treatment,there were not significant differences in the activities of nitrate reductase and peptidase and in the content of free amino acid, but there was a significant increase in GTP activity and a significant decrease in free amino acid in transgenic Bt cotton leaves. Except for the soluble protein content, all the other characteristics of nitrogen metabolism of Bt-CpTI transgenic cotton Z41 changed significantly. Both the peptidase activity and the soluble protein content in Bt-CpTI transgenic cotton SK321 increased significantly, but the activities of nitrate reductase and GTP and the content of free amino acid in that treatment didn’t change obviously. The unantichipated effects of transgenic crops would be more uncertain and complex along with diversification of transgenic genes.

Key words: Allelopathy, Root exudates, Eggplant, Graft, Autotoxicity