Journal of Integrative Agriculture ›› 2014, Vol. 13 ›› Issue (5): 1036-1042.DOI: 10.1016/S2095-3119(13)60532-8

• 论文 • 上一篇    下一篇

The Minimal Active Fragment of the Cry1Ai Toxin is Located Between 36I and 605I

 ZHOU Zi-shan, LIN Hui-yan, LI Ying, SHU Chang-long, SONG Fu-ping , ZHANG Jie   

  1. State Key Laboratory for Biology of Plant Diseases and Insect Pests/Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, P.R.China
  • 收稿日期:2013-03-20 出版日期:2014-05-01 发布日期:2014-05-06
  • 通讯作者: ZHANG Jie, Tel: +86-10-62815921, Fax: +86-10-62812642, E-mail: jzhang@ippcaas.cn
  • 基金资助:

    This study was supported by the National Natural ScienceFoundation of China (31272115), the National 973 Program of China (2009CB118902). We thank Ms. Liang Yingping and Liu Shuqin from Institution of Plant Protection, Chinese Academy of Agricultural Sciences, for their assistance with insect rearing and the bioassays.

The Minimal Active Fragment of the Cry1Ai Toxin is Located Between 36I and 605I

 ZHOU Zi-shan, LIN Hui-yan, LI Ying, SHU Chang-long, SONG Fu-ping , ZHANG Jie   

  1. State Key Laboratory for Biology of Plant Diseases and Insect Pests/Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, P.R.China
  • Received:2013-03-20 Online:2014-05-01 Published:2014-05-06
  • Contact: ZHANG Jie, Tel: +86-10-62815921, Fax: +86-10-62812642, E-mail: jzhang@ippcaas.cn
  • Supported by:

    This study was supported by the National Natural ScienceFoundation of China (31272115), the National 973 Program of China (2009CB118902). We thank Ms. Liang Yingping and Liu Shuqin from Institution of Plant Protection, Chinese Academy of Agricultural Sciences, for their assistance with insect rearing and the bioassays.

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摘要： The novel cry1Ai gene that cloned from Bacillus thuringiensis strain SC6H8 encoded a protein exhibiting strong toxicity against Plutella xylostella and Chilo suppressalis in our previous study. Using the available information for the active fragments of other Cry toxins, eight truncated fragments were constructed to identify the minimal active fragment of Cry1Ai. All truncated fragments were expressed in Escherichia coli strain BL21 (DE3), and the insecticidal activity against 2nd- instar P. xylostella larvae was assessed using full-length Cry1Ai as a positive control. The results indicate that the minimal active fragment of the Cry1Ai toxin against P. xylostella is located between amino acid residues 36I and 605I, which is smaller than the regions previously reported for Cry1A. The first two amino acids (34T and 35P) on helix α-1 and whole helix α-2 of domain I and sheet β-32 of domain III are necessary for Cry1Ai toxin to keep its toxicity against P. xylostella.

关键词: Bacillus thuringiensis , Cry1Ai toxin , active fragment , toxicity , Plutella xylostella

Abstract: The novel cry1Ai gene that cloned from Bacillus thuringiensis strain SC6H8 encoded a protein exhibiting strong toxicity against Plutella xylostella and Chilo suppressalis in our previous study. Using the available information for the active fragments of other Cry toxins, eight truncated fragments were constructed to identify the minimal active fragment of Cry1Ai. All truncated fragments were expressed in Escherichia coli strain BL21 (DE3), and the insecticidal activity against 2nd- instar P. xylostella larvae was assessed using full-length Cry1Ai as a positive control. The results indicate that the minimal active fragment of the Cry1Ai toxin against P. xylostella is located between amino acid residues 36I and 605I, which is smaller than the regions previously reported for Cry1A. The first two amino acids (34T and 35P) on helix α-1 and whole helix α-2 of domain I and sheet β-32 of domain III are necessary for Cry1Ai toxin to keep its toxicity against P. xylostella.

Key words: Bacillus thuringiensis , Cry1Ai toxin , active fragment , toxicity , Plutella xylostella