棉 花 学 报   Cotton  Science  2010，22（2）：150-156

Effect of GA₃ and DPC on Bt Protein Expression and Boll Nitrogen Metabolism of Bt Transgenic Cotton
ZHANG Xiang, MA Ai-li, FANG Jing, XIAO Jian, LUAN Na, WANG Yong-hui, CHEN Yuan, CHEN De-hua^*
(Key Laboratory of Crop Genetics and Physiology of Jiangsu Province/Key Laboratory of Crop Physiology, Ecology and Cultivation in Middle and Lower Reaches of Yangtze River of Ministry of Agriculture, Yangzhou, Jiangsu 225009, China)

Abstract: In order to study the effect of the plant growth rugulators on Bt protein expression and nitrogen metabolism of the bolls, GA₃ and DPC were used to spray bolls of the two Bt cotton cultivars (Sikang 1 was conventional, Siza 3 was hybrid). The results showed that DPC increased Bt protein contents of bolls at 10 days post anthesis (DPA) and 30 DPA; GA₃ decreased the Bt protein contents of the boll shell and the seeds at 10 DPA, but enhanced the contents at 30 DPA. Bolls with DPC treatment had higher total nitrogen, free amino acid and soluble content, greater in NR, GPT and GOT activity. Bolls with spraying GA3 had an opposite effect at 10 DPA. There were similar results for the two Bt cultivars with different genotypes. There were significant positive correlation between the Bt toxin content and the activity of the NR, GPT and GOT. The correlation coefficients were 0.8776^**, 0.7172^** and 0.7028^**. The results suggest that spraying DPC and GA₃ during boll nutrient filling may enhance nitrogen metabolism intensity, promote the expression of the Bt protein and increase the ability of the insect resistance.
Key words: Bt cotton; Bt protein; nitrogen; growth regulator    [Full Text, 297KB]