RICE SCIENCE ›› 2009, Vol. 16 ›› Issue (3): 181-186 .DOI: 10.1016/S1672-6308(08)60077-3

• Research Paper • Previous Articles     Next Articles

Development of Marker-Free Transgenic Cry1Ab Rice with Lepidopteran Pest Resistance by Agrobacterium Mixture-Mediated Co-transformation

QI Yong-bin 1, 2; YE Sheng-hai 1; LU Yan-ting 1; JIN Qing-sheng 1; ZHANG Xiao-ming 1   

  1. 1Institute of Crop and Nuclear Technology Utilization, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China; 2Biotechnology Institute, Zhejiang University, Hangzhou 310029, China
  • Received:2008-06-16 Online:2009-09-28 Published:2009-09-28
  • Contact: ZHANG Xiao-ming
  • Supported by:
    the Zhejiang Provincial Natural Science Foundation of China (Grant No. Z305650 and No. Y3080361), the Science and Technology Department of Zhejiang Province, China (Grant No. 2004C12020), the National Key Technology Research & Development Program, China (Grant No. 2006BAD01A01-5 and No. 2008ZX08001-001), the 151 Foundation for the Talents of Zhejiang Province, China.

Abstract: Cry1Ab gene was transformed into four rice varieties, Zhejing 22, Zhejing 27, Jiahua 1 and Xiushui 63 mediated by Agrobacterium-mixture co-transformation. Rice genotype had an important effect on callus induction and transformation efficiency. Different mixtures of Agrobacterium strains (EHA105 and EHA101) contained Hpt and Cry1Ab genes resulted in different frequencies of resistant calli. There was no correlation between the frequency of transformants with the ratio of the Agrobacterium strain mixture contained Hpt and Cry1Ab genes. A total of 509 transgenic plants were obtained from the four rice varieties, and 272 T2 progenies were analyzed for Cry1Ab and Hpt genes. PCR analysis revealed that 412 regenerated plants were Hpt positive (80.94%), 62 plants were also Cry1Ab co-transformants (15.05% in total frequency), and 42 plants among the 272 T2 progenies were Cry1Ab positive but Hpt negative. This suggests that marker-free transgenic plants could be produced by co-transformation mediated by mixed Agrobacterium strains with the selectable marker gene and target gene. Southern blot analysis of five independent marker-free T2 transgenic lines co-transformed from Zhejing 22 showed that Cry1Ab gene had been inserted into rice genome with a single copy. The transgenic plants showed significantly stronger resistance to lepidopteron than the non-transgenic plants under no application of insecticides against lepidopteron.

Key words: rice (Oryza sativa), Agrobacterium mixture-mediated co-transformation, Cry1Ab gene, Hpt gene, gene transfer, marker-free transgenic plants, pest resistance