Overexpression of a Foreign Bt Gene in Cotton Affects the Low-Molecular-Weight Components in Root Exudates  

作　　者：YAN Wei-Dong SHI Wei-Ming LI Bao-Hai ZHANG Min 

机构地区：[1]State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing210008 （China）

出　　处：《Pedosphere》2007年第3期324-330,共7页土壤圈（英文版）

基　　金：Project supported by the Knowledge Innovation Program of the Institute of Soil Science, Chinese Academy of Sciences,and the National Natural Science Foundation of China (No. 30270789).

摘　　要：Most research in the past using genetically modified crops (GM crops) has focused on the ecological safety of foreign gene (i.e., the gene flow), gene products (for example, Bt (Bacillus thuringiensis) protein), and the safety of transgenic food for humans. In this study, changes in both the species and amounts of low-molecular-weight components in cotton (Gossypium hirsutum L.) root exudates after foreign Bt gene overexpression were investigated under different nutritional conditions. Transgenic cotton containing Bt (Bt-cotton), supplemented with all the mineral nutrients, secreted more organic acids than the wild-type cotton (WT). When nitrogen was removed from the full-nutrient solution, the amount of organic acids secretion of Bt-cotton was lesser than that of WT. The roots of the transgenic cotton secreted lesser amounts of amino acids and soluble sugars than the WT roots in the full-nutrient solution. Deficiencies of P and K caused a large increase in the total amino acid and soluble sugar secretions of both Bt-cotton and WT, with larger increases observed in Bt-cotton. Because transferring the foreign Bt gene into cotton can result in alterations in the components of the root exudates, with the effect varying depending on the nutritional status, the cultivation of genetically modified crops, such as Bt-cotton, in soil environments should be more carefully assessed, and the possible effects as a result of the alterations in the root exudate components should be considered.Most research in the past using genetically modified crops （GM crops） has focused on the ecological safety of foreign gene （i.e., the gene flow）, gene products （for example, Bt （Bacillus thuringiensis） protein）, and the safety of transgenic food for humans. In this study, changes in both the species and amounts of low-molecular-weight components in cotton （Gossypium hirsutum L.） root exudates after foreign Bt gene overexpression were investigated under different nutritional conditions. Transgenic cotton containing Bt （Bt-cotton）, supplemented with all the mineral nutrients, secreted more organic acids than the wild-type cotton （WT）. When nitrogen was removed from the full-nutrient solution, the amount of organic acids secretion of Bt-cotton was lesser than that of WT. The roots of the transgenic cotton secreted lesser amounts of amino acids and soluble sugars than the WT roots in the full-nutrient solution. Deficiencies of P and K caused a large increase in the total amino acid and soluble sugar secretions of both Bt-cotton and WT, with larger increases observed in Bt-cotton. Because transferring the foreign Bt gene into cotton can result in alterations in the components of the root exudates, with the effect varying depending on the nutritional status, the cultivation of genetically modified crops, such as Bt-cotton, in soil environments should be more carefully assessed, and the possible effects as a result of the alterations in the root exudate components should be considered.

关 键 词：gene overexpression low-molecular-weight components nutritional status root exudates transgenic cotton 

分 类 号：S562[农业科学—作物学]