Transformation of peanut (Arachis hypogaea L.): a non-tissue culture based approach for generating transgenic plants

Transgenic peanut (Arachis hypogaea L. cv. TMV-2) plants have been produced by a tissue culture-independent Agrobacterium tumefaciens-mediated transformation procedure. Embryo axes of mature seeds with one cotyledon excised were incubated on Murashige and Skoog (MS) gelled medium for 2 days, then pricked randomly with a sterile needle and infected by immersion in a suspension of Agrobacterium in Winans’ AB medium that was added with wounded tobacco leaf extract. Agrobacterium strain LBA 4404 harboring the binary vector pKIWI105 that carries the genes for β-glucuronidase (GUS) and neomycin phosphotransferase (NPT II) was used for transformation. Following a 16 h infection, 18 h decontamination with cefotaxime and germination and growth on soilrite for 16 days under growth room conditions, the seedlings were transferred to greenhouse. About 3.3% of the seedlings were GUS positive as determined by histochemical assay and by PCR analysis. Molecular characterization of primary transformants as well as the T1 and T2 generation plants has shown that the method ensured insertion, expression and inheritance of foreign genes in peanut.