Journal of Integrative Agriculture ›› 2013, Vol. 12 ›› Issue (3): 436-444.DOI: 10.1016/S2095-3119(13)60244-0

• 论文 • 上一篇    下一篇

NaCl-Induced Changes of Ion Fluxes in Roots of Transgenic Bacillus thuringiensis (Bt) Cotton (Gossypium hirsutum L.)

 LI Mao-ying, LI Fang-jun, YUE Yue-sen, TIAN Xiao-li, LI Zhao-hu , DUAN Liu-sheng   

  1. State Key Laboratory of Plant Physiology and Biochemistry /Engineering Research Center of Plant Growth Regulator,Ministry of Education/College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, P.R.China
  • 收稿日期:2012-02-23 出版日期:2013-03-01 发布日期:2013-03-10
  • 通讯作者: Correspondence DUAN Liu-sheng, Tel/Fax: +86-10-62731301, E-mail: duanlsh@cau.edu.cn
  • 基金资助:

    This work was supported by the National Natural Science Foundation of China (30871490) and the Specialized Research Fund for the Doctoral Program of Higher Education of China, and the Innovation Fund for Graduate Students of China Agricultural University (KYCX2011007).

NaCl-Induced Changes of Ion Fluxes in Roots of Transgenic Bacillus thuringiensis (Bt) Cotton (Gossypium hirsutum L.)

 LI Mao-ying, LI Fang-jun, YUE Yue-sen, TIAN Xiao-li, LI Zhao-hu , DUAN Liu-sheng   

  1. State Key Laboratory of Plant Physiology and Biochemistry /Engineering Research Center of Plant Growth Regulator,Ministry of Education/College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, P.R.China
  • Received:2012-02-23 Online:2013-03-01 Published:2013-03-10
  • Contact: Correspondence DUAN Liu-sheng, Tel/Fax: +86-10-62731301, E-mail: duanlsh@cau.edu.cn
  • Supported by:

    This work was supported by the National Natural Science Foundation of China (30871490) and the Specialized Research Fund for the Doctoral Program of Higher Education of China, and the Innovation Fund for Graduate Students of China Agricultural University (KYCX2011007).

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摘要： Bacillus thuringiensis (Bt) cotton is grown worldwide, including in saline soils, but the effect of salinity on ion fluxes of Bt cotton remains unknown. Responses of two transgenic Bt cotton genotypes (SGK321 and 29317) and their corresponding receptors, Shiyuan 321 (SY321) and Jihe 321 (J321), to 150 mmol L-1 NaCl stress were studied in a growth chamber. The root dry weight of SGK321 and 29317 under NaCl treatment was decreased by 30 and 31%, respectively. However, their corresponding receptor cultivars SY321 and J321 were less affected (19 and 24%, respectively). The root length and surface area of the Bt cultivars were significantly decreased relative to their receptors under salt stress. NaCl treatment significantly increased Cry1Ac mRNA transcript levels in SGK321 and 29317 but did not affect Bt protein content in leaves or roots of either cultivar at 1 and 7 d after NaCl treatment. Fluxes of Na+, K+, and H+ in roots were investigated using the scanning ion-selective electrode technique. Both mean K+ efflux rate and transient K+ efflux of the Bt cultivars increased four-fold compared to their corresponding receptors when exposed to salinity stress. There were no significant differences in Na+ efflux between Bt and non-Bt cottons. Furthermore, the Na+ contents in roots and leaves of all genotypes dramatically increased under salt stress, whereas K+ contents decreased. Our results suggested that Bt cotton cultivars are more sensitive to salt stress than their receptor genotypes.

关键词: transgenic Bt cotton , salinity stress , toxin protein , SIET , K+ flux

Abstract: Bacillus thuringiensis (Bt) cotton is grown worldwide, including in saline soils, but the effect of salinity on ion fluxes of Bt cotton remains unknown. Responses of two transgenic Bt cotton genotypes (SGK321 and 29317) and their corresponding receptors, Shiyuan 321 (SY321) and Jihe 321 (J321), to 150 mmol L-1 NaCl stress were studied in a growth chamber. The root dry weight of SGK321 and 29317 under NaCl treatment was decreased by 30 and 31%, respectively. However, their corresponding receptor cultivars SY321 and J321 were less affected (19 and 24%, respectively). The root length and surface area of the Bt cultivars were significantly decreased relative to their receptors under salt stress. NaCl treatment significantly increased Cry1Ac mRNA transcript levels in SGK321 and 29317 but did not affect Bt protein content in leaves or roots of either cultivar at 1 and 7 d after NaCl treatment. Fluxes of Na+, K+, and H+ in roots were investigated using the scanning ion-selective electrode technique. Both mean K+ efflux rate and transient K+ efflux of the Bt cultivars increased four-fold compared to their corresponding receptors when exposed to salinity stress. There were no significant differences in Na+ efflux between Bt and non-Bt cottons. Furthermore, the Na+ contents in roots and leaves of all genotypes dramatically increased under salt stress, whereas K+ contents decreased. Our results suggested that Bt cotton cultivars are more sensitive to salt stress than their receptor genotypes.

Key words: transgenic Bt cotton , salinity stress , toxin protein , SIET , K+ flux