Peanut (Arachis hypogaea L.) is an economically important oilseed crop which is grown widely in the semi-arid tropics, and India being the second largest producer in world with annual yield of 5.78 MT (FAOSTAT, 2012).
Aflatoxin contamination of peanut has gained global significance due to the deleterious effects of these contaminants on human and livestock health, and the consequent importance in international trade. Although, aflatoxin contamination does not affect crop productivity, it makes the produce unfit for consumption while the higher aflatoxins load in the exportable commodities jeopardize the export earnings. Breeding efforts so far have not
resulted in varieties with durable resistance to high levels of A. flavus infection and consequent aflatoxin production. Biotechnological applications involving the genetic engineering technology provides an attractive approach for developing transgenic events to circumvent this important problem. Plant lipoxygenases (LOXs) are hypothesized to play an important role in mediating host-pathogen interactions by initiating the octadecanoic branch
in response to fungal attack, catalyzing the oxidation of polyunsaturated fatty acids such as linoleic acid (18:2) and α-linolenic acid (18:3) to produce unsaturated fatty acid hydroperoxides. Jasmonic acid (JA), a derivative of α-
linolenic acid has been reported as a potent inhibitor of aflatoxin biosynthesis. At ICRISAT, work was initiated using the LOX gene approach for addressing this recalcitrant problem in peanut. A highly efficient peanut
transformation protocol using cotyledon explants was used to produce 25 marker-free transgenic events of peanut by incorporating PnLOX3 gene under the control of constitutive and seed specific promoters. These transgenic events were characterized at molecular level using PCR, Southern
hybridization and RT-PCR assays for the presence and expression of the transgene which were further evaluated under contained greenhouse conditions
