African Journal of Biotechnology Vol. 5 (20), pp. 1989-1993, 16 October 2006   

ISSN 1684–5315 © 2006 Academic Journals        

Full Length Research Paper

Transformation of multiple soybean cultivars by infecting cotyledonary-node with Agrobacterium tumefaciens

Xinping YI and Deyue YU*

Nanjing Agricultural University, National Center for Soybean Improvement, National

Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing 210095, China.

*Corresponding authors E-mail: dyyu@njau.edu.cn.  Tel/Fax:+86-25-84396410.

Abbreviations: GFP, green fluorescent protein; BA, 6:benzylaminopurine; DTT,

dithiolthreitol; IBA, indole-3-butyric acid

Accepted 25 August, 2006

Transformation of four soybean cultivars (Nannong88-1, Nannong18-6, Yu23 and Nannong 87C-38) by infecting cotyledonary-node with Agrobacterium tumefaciens strain EHA105 harboring pBI121 containing GFP reporter gene was conducted. The results indicated that the addition of thiol compounds (L-cysteine, dithiothreitol and sodium thiosulfate) in co-cultivation period increased the transformation efficiency of all four soybean cultivars, with Nannong 88-1 most increased up to 2.20%. Detection of GFP expression in the rooted plants was an effective selection system for the confirmation of soybean transformation. And most GFP-positive plants were confirmed to be positive by Southern blot analysis, which showed that transformation of cotyledonary-node explants mediated by Agrobacterium delivered T-DNA with one or two copies into soybean genome. In our study, the combination of Nannong88-1 with EHA105 is the optimum selection for explant and bacterial inoculum in soybean transformation, which could be applied in future functional study of soybean genes.

Key words: Soybean, cotyledonary–node, Agrobacterium, transformation, GFP.