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 T 1 and T 2 generation plants has shown that the method ensured insertion, expression and inheritance of foreign genes in peanut.