Pedosphere 17(3): 324--330, 2007
ISSN 1002-0160/CN 32-1315/P
©2007 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Overexpression of a foreign Bt gene in cotton affects the low-molecular-weight components in root exudates |
YAN Wei-Dong , SHI Wei-Ming, LI Bao-Hai and ZHANG Min |
| State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China). E-mail: yanwd@issas.ac.cn |
| ABSTRACT |
| 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. |
| Key Words: gene overexpression, low-molecular-weight components, nutritional status, root exudates, transgenic cotton |
| Citation: Yan, W. D., Shi, W. M., Li, B. H. and Zhang, M. 2007. Overexpression of a foreign Bt gene in cotton affects the low-molecular-weight components in root exudates. Pedosphere. 17(3): 324-330. |
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