棉 花 学 报       Cotton Science     2009，21(4)：302-306

Effects of Temperature Stress on Bt Insecticidal Protein Expression in Bt Transgenic Cotton Leaves and Death Rate of Cotton Bollworm
ZHOU Gui-sheng^1，2，ZHOU Fu-cai³，XIE Yi-ming⁴，FENG Chao-nian^1，2，YANG Yi-zhong³
(1.Key Laboratory of Jiangsu Provincial Crop Genetics and Physiology of Yangzhou University,Yangzhou,Jiangsu 225009, China；2.Laboratory of Crop Physiology,Ecology and Cultivation in Middle and Lower Reaches of Yangtze River of Ministry of Agriculture,Yangzhou University, Yangzhou, Jiangsu 225009, China; 3.School of Horticulture and Plant Protection, Yangzhou University, Yangzhou, Jiangsu 225009, China；4.Yangzhou Meteorological Bureau, Yangzhou,Jiangsu 225009, China )

Abstract：With Bt transgenic cotton plants of Kemian 1 as the testing material, temperature stress experiments ( 20℃, 25℃, 35℃，and 40℃) were carried out in temperature and light controlled compartments to investigate Bt insecticidal protein content in cotton leaves at flowering stage, the death rate of bollworm fed on cotton leaves, and the relationship between them. The results indicated that free amino acid content increased under temperature stress, with the biggest increment during the first 12 h. The content of soluble protein decreased, presenting a sharp decrement during the first 12 h. Bt insecticidal protein content in leaves subjected to temperature stress decreased significantly during the first 24 h, and the biggest decrements occurred during the first 12 h. The death rate of bollworm fed on the leaves subjected to 25 ℃ was higher than the death rates of bollworm eating the leaves subjected to 20 ℃ and 35 ℃ . Under the same temperature, the longer the leaves were subjected to temperature stress, the lower the death rate of bollworm fed on these leaves was. The death rate of bollworm 72 h after eating the leaves was significantly higher than the death rate of bollworm 144 h after eating the leaves. Correlation analyses showed that the contents of Bt insecticidal protein, free amino acid, soluble protein and the death rate of bollworm 72 h after eating the leaves were significantly correlated at 0.05 level or at 0.01 level. The increment of free amino acid, the decrement of Bt insecticidal protein, and the death rate of bollworm 72 h after eating the treated leaves were significantly correlated at 0.05 level.
Key words：temperature；stress; Bt transgenic cotton; bollworm; death rate    [Full Text, 2219KB]