Updated project metadata. Null mutations for genes encoding the major seed storage protein in pea, vicilin, were sought among a fast-neutron mutant population. Combinations of four and five mutations, where individual vicilin loci had been deleted, were generated to address the question of how removal or reduction of a major storage protein would impact on seed protein concentration and yield. While seed protein concentrations were not reduced in mutant lines, indicative of a re-balancing of the proteome, there were notable differences in their metabolite, proteomic and amino acid profiles. The genomic regions which were deleted were defined by whole genome sequencing of the parental line, JI2822 and its quintuple vicilin null derivative.