Abstract
Problem statement: The present study investigates the ability of the pTok47 supervirulence plasmid form Agrobacterium tumefaciens A281 to enhance genetic transformation in Hevea brasiliensis. Approach: Hevea anther callus was transformed via Agrobacterium-mediated genetic transformation using two strains of Agrobacterium (GV2260 and GV3850) harboring the human serum albumin cDNA and the supervirulent plasmid pToK47 from Agrobacterium tumefaciens A281. The transformed callus was selected using kanamycin as the selection agent Results: The Agrobacterium strain GV2260 benefited from the presence of the supervirulence plasmid in giving a higher frequency of 7.4% transformed callus, 344.8% embryogenesis and 11.6% plantlet production compared to the corresponding strain on its own giving 0.9% transformed callus, 204.5% embryogenesis and 4.4% plantlet production. Similarly, Agrobacterium strain GV3850 conferred a higher frequency using the supervirulent plasmid, resulting in 3.5% transformed callus, 138.5% embryogenesis and 3.5% plantlet production compared to the corresponding strain on its own giving 0.7% transformed callus, 137.5% embryogenesis and 9.0% plantlet production. These findings were confirmed by the Wilcoxon Signed Rank Test that compared the effectiveness of the supervirulence plasmid in increasing the rate of genetic transformation in the calli surviving in kanamycin growth medium for GV2260 (p<0.001) and for GV3850 (p<0.05). Conclusion: This study showed that both Agrobacterium strains benefited from the presence of the supervirulence plasmid in giving a higher frequency of transformed callus, embryoids and plantlets. These results suggest that a highly virulent binary vector system might prove especially useful in generating high frequency transformation of Hevea.
Highlights
The main challenge with genetic transformation of tree species is achieving high transformation efficiency for desired clones or cultivars
In A. tumefaciens A281 the tumors formed after infection with plant cells were larger, were early-appearing and the tumurogenesis applied to a wide range of plants, compared to other A. tumefaciens strains[4]
Southern analysis with the DIG HIGH-PRIME labeled NPTII and HSA probe showed a hybridization signal in the six transformed tissues analyzed (Fig. 2a and b). These results show that sustained growth and development of the callus culture on kanamycin medium is a good indicator of successful genetic transformation
Summary
The main challenge with genetic transformation of tree species is achieving high transformation efficiency for desired clones or cultivars. In this respect, it is important to have an efficient tissue culture system to obtain plantlets from cells containing the transgene. Agrobacterium tumefaciens harbors a tumorinducing plasmid (Ti plasmid) and the region of TDNA within this plasmid encodes for the expression of the plant growth regulator genes for auxin and cytokinin, which leads to the formation of tumors in plant cells[1,2]. In A. tumefaciens A281 (the carrier of the plasmid pTiBo542) the tumors formed after infection with plant cells were larger, were early-appearing and the tumurogenesis applied to a wide range of plants, compared to other A. tumefaciens strains[4]. When mobilized into Agrobacterium strains A348, A281, A208 and T37
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: American Journal of Biochemistry and Biotechnology
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
