Self-incompatibility (SI), a mechanism preventing self-pollination, has been intensively studied over the past 60 years among angiosperms. In grasses, we recently identified the genes responsible for the recognition of self-pollen by the pistil (Rohner et al, 2023). This unique grass SI system is governed by two multi-allelic loci, S and Z, each containing three genes. For each locus, two genes expressed in pollen, annotated as containing ...