Elimination of zero-repeat subunit in allergenic seed protein 13S globulin using the novel allele in common buckwheat ( Moench).

Common buckwheat ( Moench) seeds contain 13S globulin, the zero-repeat subunit of which is trypsin-resistant and allergenic. Here, its two novel alleles were analyzed for development of hypoallergenic plants. The allele has a Miniature Inverted-repeat Transposable Element (MITE)-like insertion in the 4th exon. However, most of the insertion was spliced-out, resulting in accumulation of zero-repeat subunit in homozygotes. Meanwhile, the has a 164-bp insertion in the 3rd exon, resulting in no accumulation of zero-repeat subunit in homozygotes (NB2_homo). Both the insertion sequences were predicted to form a hairpin-like structure, and that of was more rigid than that of . Trypsin digestion in NB2_homo showed that the α polypeptide of Met-rich subunit is also hard to digest, that is a next target to eliminate for hypoallergenic buckwheat development.