Underpinning the Genetic Regulation of Immunogenic Protein Accumulation in Peanut Seeds: A Preamble to Developing Reduced Immunogenicity Lines

Peanut is a vital food and oilseed crop in the South and Southeast United States. Unfortunately, peanut allergy (PA), which affects 2.9% of the U.S. population, is primarily caused by four allergenic proteins: Arah1, Arah2, Arah3, and Arah6. PA impacts sensitive individuals and their families, restricting peanut use in public spaces such as airplanes and schools. Current solutions, such as abstinence, Palforzia, and Xolair, have limitations. This study aims to develop an affordable genetics- and plant breeding-based solution to PA. To this end, a panel of approximately 250 peanut lines, including genotypes from USDA and ICRISAT mini-core collections, wild and synthetic lines, landraces, and cultivars, was profiled for seed proteins. This analysis identified genotypes with reduced immunogenic protein content, including diploid Arachis diogoi GKP10602 and tetraploid NC-25. Interestingly, these lines were previously used to develop an introgression line (IL) and recombinant inbred line (RIL) populations at the University of North Carolina. These populations were genotyped using amplicon sequencing and phenotyped through densitometric analysis, mass spectrometry, ELISA, and Western blotting. GWAS and QTL mapping revealed that the genetic regulation of seed storage protein accumulation is largely governed by trans-QTLs, mapping to chromosomes other than those carrying genes for Arah1, Arah2, Arah3, and Arah6. This information led to the development of DNA markers for breeding peanuts with reduced immunogenicity and the identification of ILs/RILs for genetic crossing. Additionally, CRISPR-mediated multi-gene editing is being used to induce mutations in the allergenic genes. This research will help develop peanut genotypes with reduced allergen content.