Collaborative non-self recognition system in S-RNase-based self-incompatibility.

Self-incompatibility in flowering plants prevents inbreeding and promotes outcrossing to generate genetic diversity. In Solanaceae, a multiallelic gene, S-locus F-box (SLF), was previously shown to encode the pollen determinant in self-incompatibility. It was postulated that an SLF allelic product specifically detoxifies its non-self S-ribonucleases (S-RNases), allelic products of the pistil determinant, inside pollen tubes via the ubiquitin-26S-proteasome system, thereby allowing compatible pollinations.