Rebalancing the seed proteome following deletion of vicilin-related genes in pea (Pisum sativum L.).

Null mutations for genes encoding a major seed storage protein in pea, vicilin, were sought through screening a fast-neutron mutant population. Deletion mutations at four or five vicilin loci, where all vicilin genes within each locus were deleted, were combined to address the question of how removal or reduction of a major storage protein and potential allergen might impact the final concentration of protein per unit of mature seed weight, seed yield, and viability. While the concentration of seed protein was not reduced in mature seeds of mutant lines, indicative of a re-balancing of the proteome, notable differences were apparent in the metabolite, proteomic, and amino acid profiles of the seeds, as well as in some functional properties. Major effects of the deletions on the proteome were documented. The genomic regions which were deleted were defined by whole-genome sequencing of the parental line, JI2822, and its quintuple vicilin null derivative, providing a comprehensive description of each vicilin locus and its genic arrangement. An annotated reference genome has been generated for JI2822, which will serve as a very valuable resource for the research community and support further study of the associated deletion mutant population.