Distribution of allergen composition in peanut (Arachis hypogaea L.) and wild progenitor (Arachis) species

Arah 1, Arah 2, and Arah 3 are the major allergens found in peanut (Arachis hypogaea L.) seed. We analysed 60 accessions in the core of the U.S. peanut core collection, along with 88 Florida peanut breeding programs lines, by qualification of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) patterns. The core of the core collection showed a wider range of allergen content than the Florida breeding lines; however, average levels of the allergens were the same for both germplasm sources. Geographic origin of the accession had no bearing on the levels of the allergens measured. The accession PI 288210 from India had the lowest level of Ara h 1 (70%). Accession PI 372305 from Nigeria had the highest level of Ara h 2 (6.2%). Accession PI 494795 from Zambia had the highest level of Ara h 2 (13.2%), but the lowest level of Ara h 2 (21.8%). Null mutants for the major allergens were not detected; however, two accessions 20 lines, and two peanut cultivars (Florunner and Georgia Red) contained no or little of a 36 kDa Ara h 3 isoform, Ara h 3-im. Comparing the seed protein profiles of the putative progenitors of the peanut A and B genomes, A. duranensis and A. ipaensis, respectively, to the commercial cultivar Georgia Green, allowed the subgenome origin of each allergen polypeptide to be determined. Collectively, these results indicate that eliminating all of the major allergens to create a hypoallergenic peanut is limited with the peanut germplasm currently available and would benefit from the reverse genetic approaches.