title: Effects of Soil Salinity on the Expression of Bt Toxin (Cry1Ac) and the Control Efficiency of Helicoverpa armigera in Field-Grown Transgenic Bt Cotton.
abstract: An increasing area of transgenic Bacillus thuringiensis (Bt) cotton is being planted in saline-alkaline soil in China. The Bt protein level in transgenic cotton plants and its control efficiency can be affected by abiotic stress, including high temperature, water deficiency and other factors. However, how soil salinity affects the expression of Bt protein, thus influencing the control efficiency of Bt cotton against the cotton bollworm (CBW) Helicoverpa armigera (Hübner) in the field, is poorly understood. Our objective in the present study was to investigate the effects of soil salinity on the expression of Bt toxin (Cry1Ac) and the control efficiency of Helicoverpa armigera in field-grown transgenic Bt cotton using three natural saline levels (1.15 dS m-1 [low soil-salinity], 6.00 dS m-1 [medium soil-salinity] and 11.46 dS m-1 [high soil-salinity]). We found that the Bt protein content in the transgenic Bt cotton leaves and the insecticidal activity of Bt cotton against CBW decreased with the increasing soil salinity in laboratory experiments during the growing season. The Bt protein content of Bt cotton leaves in the laboratory were negatively correlated with the salinity level. The CBW populations were highest on the Bt cotton grown in medium-salinity soil instead of the high-salinity soil in field conditions. A possible mechanism may be that the relatively high-salinity soil changed the plant nutritional quality or other plant defensive traits. The results from this study may help to identify more appropriate practices to control CBW in Bt cotton fields with different soil salinity levels.
authors.affiliation: Key Laboratory of Crop Physiological Ecology and Production Management, Ministry of Agriculture, and Department of Agronomy, Nanjing Agricultural University, Nanjing, Jiangsu, China.|State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, Henan, China.
authors.forename: Jun-Yu
authors.initials: JY
authors.lastname: Luo
authors.affiliation: State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, Henan, China.
authors.forename: Shuai
authors.initials: S
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, Henan, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Peng
authors.affiliation: State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, Henan, China.
authors.forename: Xiang-Zhen
authors.initials: XZ
authors.lastname: Zhu
authors.affiliation: State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, Henan, China.
authors.forename: Li-Min
authors.initials: LM
authors.lastname: Lv
authors.affiliation: State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, Henan, China.
authors.forename: Chun-Yi
authors.initials: CY
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, Henan, China.
authors.forename: Chun-Hua
authors.initials: CH
authors.lastname: Li
authors.affiliation: Key Laboratory of Crop Physiological Ecology and Production Management, Ministry of Agriculture, and Department of Agronomy, Nanjing Agricultural University, Nanjing, Jiangsu, China.
authors.forename: Zhi-Guo
authors.initials: ZG
authors.lastname: Zhou
authors.affiliation: State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, Henan, China.
authors.forename: Jin-Jie
authors.initials: JJ
authors.lastname: Cui
mesh_terms: D000818:Animals; D001413:Bacillus thuringiensis / Q000235:genetics; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000096:biosynthesis*; D004731:Endotoxins / Q000096:biosynthesis*; D003368:Gossypium / Q000235:genetics* / Q000378:metabolism*; D006460:Hemolysin Proteins / Q000096:biosynthesis*; D007305:Insecticide Resistance / Q000502:physiology; D007306:Insecticides / Q000378:metabolism; D007814:Larva / Q000187:drug effects; D009036:Moths / Q000187:drug effects*; D030821:Plants, Genetically Modified / Q000235:genetics*; D054712:Salinity; D012621:Seasons; D012987:Soil / Q000737:chemistry*
chemical_list: D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D004731:Endotoxins; D006460:Hemolysin Proteins; D007306:Insecticides; D012987:Soil; C030956:insecticidal crystal protein, Bacillus Thuringiensis