Effects of Extreme Air Temperature and Humidity on the Insecticidal Expression Level of Bt Cotton  

作　　者：CHENYuan WEN Yu-jin CHEN Yuan John Tom Cothren ZHANG Xiang WANG Yong-hui WilliamA Payne CHEN De-hua 

机构地区：[1]Ecology and Cultivation in Middle and Lower Reaches of Yangtse River, Ministry of Agriculture/Agricultural College, Yangzhou University, Yangzhou 225009, P.R.China [2]Department of Soil and Crop Sciences, Texas A&M University, College Station TX77843, USA [3]Key Laboratory of Crops Genetics and Physiology, Jiangsu Province/Agricultural College, Yangzhou University, Yangzhou 225009, P.R. China [4]Norman Borlaug Institute for International Agriculture, Texas A&M University, College Station TX77843, USA

出　　处：《Journal of Integrative Agriculture》2012年第11期1836-1844,共9页农业科学学报（英文版）

基　　金：supported by the National Natural Science Foundation of China (30971727,31171479);the Priority Academic Program Development of Jiangsu Higher Education Institutions,China;the Key Laboratory Foundation of Jiangsu Province,China (10KJA210057);the Doctoral Advisor Foundation of Education Department of China(20113250110001);the Natural Science Foundation of Jiangsu Province,China (BK2009324);the New Century Academic Leader Project,Yangzhou University of China;the Qing-Lan Project,Jiangsu Provincial Educational Department,China

摘　　要：The higher survival rates of Helicoverpa amigera larvae were usually observed after adverse climate which was related to extreme temperature （T） and relative humidity （RH） stresses in transgenic Bacillus thuringiensis （Bt） cotton. The unstable resistance of Bt cotton to bollworms has been correlated with the reduced expression of CrylAc δ-endotoxin. The objective of this study was to investigate the effects of combined temperature and relative humidity stresses on the leaf CrylAc insecticidal protein expression during critical developmental stages. The study was undertaken on two transgenic cotton cultivars that share same parental background, Sikang 1 （a conventional cultivar） and Sikang 3 （a hybrid cultivar）, during the 2007 and 2008 growing seasons at the Yangzhou University Farm, Yangzhou, China. The study was arranged with two factors that consisted of temperature （two levels） and relative humidity （three levels）. The six T/RH treatments were 37℃/95%, 37℃/70%, 37℃/50%, 18℃/95%, 18℃/70%, and 18℃/50%. In 2007, the six treatments were imposed to the plants at peak flowering stage for 24 h; in 2008, the six treatments were applied to the plants at peak square, peak flowering, and peak boll stages for 48 h. The results of the study indicated that the leaf insecticidal protein expression in CrylAc was significantly affected by extreme temperature only at peak flowering stage, and by both extreme temperature and relative humidity during boll filling stage. The greatest reductions were observed when the stresses were applied at peak boll stage. In 2008, after 48 h stress treatment, the leaf Bt endotoxin expression reduced by 25.9-36.7 and 23.6-40.5% at peak boll stage, but only by 14.9-26.5 and 12.8-24.0% at peak flowering stage for Sikang 1 and Sikang 3, respectively. The greatest reduction was found under the low temperature combined with low relative humidity condition for both years. It is believed that the temperature and relative humidity stresses may be attributed to tThe higher survival rates of Helicoverpa amigera larvae were usually observed after adverse climate which was related to extreme temperature （T） and relative humidity （RH） stresses in transgenic Bacillus thuringiensis （Bt） cotton. The unstable resistance of Bt cotton to bollworms has been correlated with the reduced expression of CrylAc δ-endotoxin. The objective of this study was to investigate the effects of combined temperature and relative humidity stresses on the leaf CrylAc insecticidal protein expression during critical developmental stages. The study was undertaken on two transgenic cotton cultivars that share same parental background, Sikang 1 （a conventional cultivar） and Sikang 3 （a hybrid cultivar）, during the 2007 and 2008 growing seasons at the Yangzhou University Farm, Yangzhou, China. The study was arranged with two factors that consisted of temperature （two levels） and relative humidity （three levels）. The six T/RH treatments were 37℃/95%, 37℃/70%, 37℃/50%, 18℃/95%, 18℃/70%, and 18℃/50%. In 2007, the six treatments were imposed to the plants at peak flowering stage for 24 h; in 2008, the six treatments were applied to the plants at peak square, peak flowering, and peak boll stages for 48 h. The results of the study indicated that the leaf insecticidal protein expression in CrylAc was significantly affected by extreme temperature only at peak flowering stage, and by both extreme temperature and relative humidity during boll filling stage. The greatest reductions were observed when the stresses were applied at peak boll stage. In 2008, after 48 h stress treatment, the leaf Bt endotoxin expression reduced by 25.9-36.7 and 23.6-40.5% at peak boll stage, but only by 14.9-26.5 and 12.8-24.0% at peak flowering stage for Sikang 1 and Sikang 3, respectively. The greatest reduction was found under the low temperature combined with low relative humidity condition for both years. It is believed that the temperature and relative humidity stresses may be attributed to t

关 键 词：Bt cotton high temperature low temperature relative humidity CryIAc protein 

分 类 号：S562[农业科学—作物学] P457[天文地球—大气科学及气象学]