Molecular and genetic analyses of S4SM RNase allele in Japanese pear 'Osa-Nijisseiki' (Pyrus pyrifolia Nakai).

摘要

Japanese pears exhibit S-RNase-mediated gametophytic self-incompatibility, and 'Osa-Nijisseiki' (S2S4SM; SM=stylar-part mutant) is a self-compatible mutant from 'Nijisseiki' (S2S4), in which the S4-allele exhibits style-specific inactivation, but behaves as the functional S4-allele in pollen. It was unclear how S4 RNase mutated to S4SM RNase, despite many investigations having been carried out. In the present study, the S-RNase genes in 'Osa-Nijisseiki' and its self-compatible progenies were systematically investigated at genomic, transcriptional and translational level in comparison with its wild type, 'Nijisseiki'. The results provided evidence that the S4 RNase gene is present in the genome and expressed in the 'Osa-Nijisseiki' style, especially in the stigma, but is not transmitted to its progenies..