Development of Self-Compatible B. rapa by RNAi-Mediated S Locus Gene Silencing

The self-incompatibility (SI) system is genetically controlled by a single polymorphic locus known as the S-locus in the Brassicaceae. Pollen rejection occurs when the stigma and pollen share the same S-haplotype. Recognition of S-haplotype specificity has recently been shown to involve at least two S-locus genes, S-receptor kinase (SRK) and S-locus protein 11 or S locus Cysteine-rich (SP11/SCR) protein. Here, we examined the function of S60, one SP11/SCR allele of B. rapa cv. Osome, using a RNAi-mediated gene silencing approach. The transgenic RNAi lines were highly self-compatible, and this trait was stable in subsequent generations, even after crossing with other commercial lines. These findings also suggested that the resultant self-compatibility could be transferred to commercial cultivars with the desired performances in B. rapa.