title: Competitive interaction between two functional S-haplotypes confer self-compatibility on tetraploid Chinese cherry (Prunus pseudocerasus Lindl. CV. Nanjing Chuisi).
abstract: Self-incompatibility (SI) has been studied extensively at the molecular level in Solanaceae, Rosaceae and Scrophulariaceae, all of which exhibit gametophytic self-incompatibility (GSI). In the present study, four PpsS-haplotypes (Prunus pseudocerasus S-haplotypes) comprising at least two genes, i.e., PpsS-RNase (P. pseudocerasus S-RNase) and PpsSFB (P. pseudocerasus S-haplotype-specific F-box) have been successfully isolated in tetraploid P. pseudocerasus Lindl. CV. Nanjing Chuisi ("NC") which exhibited self-compatibility (SC), and its S-genotype was determined as S-1/S-3'/S-5/S-7. These PpsS-RNases, which were expressed exclusively in style, shared the typical structural features with S-RNases from other Prunus species exhibiting GSI. All PpsSFBs showed similar structure characteristics of SFBs from other Prunus species, and matched with the necessary conditions for pollen S-determinant. No mutations leading to dysfunction of S-haplotype were found in their full-length c-DNA sequences, except for PpsS-3'-haplotype which was not amplified by PCR. These four S-haplotypes complied with tetrasomic inheritance. Diploid pollen grains with S-genotypes S-7/S-1, S-7/S-5 and S-1/S-5 can grow the full length of the style after self-pollination, while pollen grains with S-3'/S-7, S-3'/S-1 and S-3'/S-5 cannot. These results suggest that PpsS-haplotypes-1, -5 and -7 are functional, and that competitive interaction between two of them confer self-compatibility on cultivar "NC". Furthermore, in terms of recognition specificity, diploid pollen grains carrying PpsS-3'-haplotype are equal to monoploid pollen grains carrying the other functional S-haplotype.
authors.affiliation: College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: S-X
authors.initials: SX
authors.lastname: Huang
authors.forename: H-Q
authors.initials: HQ
authors.lastname: Wu
authors.forename: Y-R
authors.initials: YR
authors.lastname: Li
authors.forename: J
authors.initials: J
authors.lastname: Wu
authors.forename: S-J
authors.initials: SJ
authors.lastname: Zhang
authors.forename: W
authors.initials: W
authors.lastname: Heng
authors.forename: S-L
authors.initials: SL
authors.lastname: Zhang
mesh_terms: D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D044783:F-Box Proteins / Q000235:genetics; D006239:Haplotypes; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000235:genetics; D053205:Pollen Tube / Q000235:genetics / Q000254:growth & development; D054817:Pollination / Q000235:genetics*; D011123:Polyploidy; D027861:Prunus / Q000235:genetics* / Q000254:growth & development*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012260:Ribonucleases / Q000235:genetics; D016415:Sequence Alignment
chemical_list: D044783:F-Box Proteins; D010940:Plant Proteins; D012260:Ribonucleases