中国农业科学 ›› 2009, Vol. 42 ›› Issue (3): 869-875 .doi: 10.3864/j.issn.0578-1752.2009.03.014

• 植物保护 • 上一篇    下一篇

植物防御素基因alfAFP(M. sativa)在毕赤酵母中的分泌表达及对水稻病原菌的抑制

  

  1. 西南大学水稻研究所

  • 收稿日期:2008-03-11 修回日期:1900-01-01 出版日期:2009-03-10 发布日期:2009-03-10
  • 通讯作者: 何光华

Secreted Expression of the Combinant Defensin alfAFP (M. sativa) in Pichia pastoris and Its Antimicrobial Activity Against Rice Pathogens in Vitro

  

  1. 西南大学水稻研究所

  • Received:2008-03-11 Revised:1900-01-01 Online:2009-03-10 Published:2009-03-10
  • Contact: HE Guang-hua

摘要:

【目的】大多数的植物防御素对不同的病原菌具有抗菌活性,其中来自苜蓿种子的防御素alfAFP的转基因土豆和番茄已经被证明对病原菌具有强抗病性。进一步研究该基因对稻瘟病、纹枯病、白叶枯病三大重要病害的抑制作用,对水稻抗病基因工程研究具有重要的意义。【方法】本试验将alfAFP构建到表达载体pPIC9K上,电转化毕赤酵母(GS115),再进行蛋白质的分泌性诱导表达,最后进行体外重组蛋白对水稻病菌的抑菌活性检测。【结果】通过15%的SDS-PAGE检测,得到大约6.5 kD的重组蛋白。alfAFP融合蛋白对水稻纹枯病、稻瘟病和白叶枯病均具有一定的抑制活性,其中对纹枯病的作用最为明显。【结论】alfAFP在酵母中成功诱导表达,并对水稻测试病菌具有一定的抑制活性,预示着alfAFP防御素基因在水稻抗病基因工程中具有潜在的应用价值。

关键词: 植物防御素alfAFP, 毕赤酵母, 抗菌活性, 稻瘟病, 白叶枯病, 纹枯病

Abstract:

【Objective】 Most plant defensins involve with defense and exhibit antimicrobial activity against various plant pathogens. Expression of the defensin AlfAFP from Medicago sativa in transgenic potato and tomato plants has been proved to possess high resistance to the pathogen. Study on antimicrobial activity of alfAFP against three main rice disease, blast, bacterial blight and sheath blight, will be significant for further research of disease resistance in transgenic rice. 【Method】 alfAFP was inserted into yeast expression vector pPIC9K, and then transferred into Pichia pastoris GS115 strain by electroporation, and alfAFP was expressed in yeast and utilized to assess antimicrobial activity in vitro. 【Result】 A molecular mass of expressed alfAFP was about 6.5 kD by 15% SDS-PAGE analysis, and the recombinant protein showed certain antimicrobial activity against Rhizoctonia solani, Magnaporthe grisea and Xanthomonas oryzae pv. oryzae, especially for Rhizoctonia solani. 【Conclusion】 Defensin alfAFP was successfully expressed in Pichia pastoris, and antimicrobial activity was detected for rice tested pathogens in vitro, indicating its potential function in breeding rice for disease resistance.

Key words: plant defensin alfAFP, Pichia pastoris, antimicrobial activity, Magnaporthe grisea, Xanthomonas oryzae pv. oryzae, Rhizoctonia solani