P. MontoroN. TeinsereeW. RattanaP. KongsawadworakulN. Michaux-FerriereKasetsart UniversityDepartment of AgricultureMahidol UniversityCIRAD Centre de Recherche de Montpellier2018-09-072018-09-072000-01-01Plant Cell Reports. Vol.19, No.9 (2000), 851-855072177142-s2.0-0033800862https://repository.li.mahidol.ac.th/handle/20.500.14594/25826The influence of CaCl2was investigated on Agrobacterium tumefaciens-mediated gene transfer in Hevea brasiliensis friable calli which are usually proliferated on maintenance medium (MM) containing 9 mM CaCl2.Five A. tumefaciens strains (C58pMP90, C58pGV2260, AGL1, LBA4404 and EHA 105) and two binary vectors (pGIN and pCAMBIA2301) were tested and the strain EHA105pC2301 was selected to conduct further experiments. The calli were precultured on MM containing a range of CaCl2concentrations, then inoculated with Agrobacterium suspension. Transfer of friable calli from MM containing 9 mM CaCl2to calcium-free medium significantly enhanced the transient β-glucuronidase activity. Interestingly, the use of calcium-free Agrobacterium resuspension medium to inoculate friable calli again dramatically increased the transformation efficiency. Induction of Agrobacterium's virulence with acetosyringone remained an important factor to stimulate transformation.Mahidol UniversityAgricultural and Biological SciencesArticleSCOPUS10.1007/s002990000208