Spontaneous and induced variability of allergens in commodity crops: Ara h 2 in peanut as a case study

Many commodity crops are grown for human consumption, and the resulting food products usually contain proteins, some of which may be allergenic. The legumes, peanut and soybean, as well as tree nuts and some cereal grains are well recognized sources of food allergens. In peanut, there are 11 documented allergenic proteins, although the major allergens are considered to be Ara h 1 and Ara h 2, both of which are seed storage proteins. Methods to reduce or eliminate these proteins from seeds are available and allow the feasibility of this approach to be tested. Greatly reduced amounts of Ara h 2 can be achieved by RNA silencing in transgenic peanut; however, mutagenesis is a more viable and socially acceptable approach to allergen elimination. Although the techniques for mutagenesis are not new, methods for mutant detection at the molecular level have recently been developed. However, these methods are dependent on genome sequence. These methods will facilitate discovery of spontaneous and induced mutations that may be useful over the long term to eliminate certain allergens from peanut.