title: Allelic diversity of S-RNase alleles in diploid potato species.
abstract: The S-ribonuclease sequences of 16 S-alleles derived from diploid types of Solanum are presented. A phylogenetic analysis and partial phenotypic analysis support the conclusion that these are functional S-alleles. S-Ribonucleases (S-RNases) control the pistil specificity of the self-incompatibility (SI) response in the genus Solanum and several other members of the Solanaceae. The nucleotide sequences of S-RNases corresponding to a large number of S-alleles or S-haplotypes have been characterised. However, surprisingly, few S-RNase sequences are available for potato species. The identification of new S-alleles in diploid potato species is desirable as these stocks are important sources of traits such as biotic and abiotic resistance. S-RNase sequences are reported here from three distinct diploid types of potato: cultivated Solanum tuberosum Group Phureja, S. tuberosum Group Stenotomum, and the wild species Solanum okadae. Partial S-RNase sequences were obtained from pistil RNA by RT-PCR or 3'RACE (Rapid Amplification of cDNA Ends) using a degenerate primer. Full-length sequences were obtained for two alleles by 5'RACE. Database searches with these sequences identified 16 S-RNases in total, all of which are novel. The sequence analysis revealed all the expected features of functional S-RNases. Phylogenetic analysis with selected published S-RNase and S-like-RNase sequences from the Solanaceae revealed extensive trans-generic evolution of the S-RNases and a clear distinction from S-like-RNases. Pollination tests were used to confirm the self-incompatibility status and cross-compatibility relationships of the S. okadae accessions. All the S. okadae accessions were found to be self-incompatible as expected with crosses amongst them exhibiting both cross-compatibility and semi-compatibility consistent with the S-genotypes determined from the S-RNase sequence data. The progeny analysis of four semi-compatible crosses examined by allele-specific PCR provided further confirmation that these are functional S-RNases.
authors: Plant and Crop Sciences Division, School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, LE12 5RD, UK.|Cell and Molecular Sciences, The James Hutton Institute, Invergowrie, Dundee, DD2 5DA, Scotland, UK.|Biotechnology Centre, College of Basic and Applied Sciences, University of Ghana, P.O. Box LG 68, Legon-Accra, Ghana.
authors: Daniel K
authors: DK
authors: Dzidzienyo
authors: Cell and Molecular Sciences, The James Hutton Institute, Invergowrie, Dundee, DD2 5DA, Scotland, UK.
authors: Glenn J
authors: GJ
authors: Bryan
authors: Cell and Molecular Sciences, The James Hutton Institute, Invergowrie, Dundee, DD2 5DA, Scotland, UK.
authors: Gail
authors: G
authors: Wilde
authors: Plant and Crop Sciences Division, School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, LE12 5RD, UK. tim.robbins@nottingham.ac.uk.
authors: Timothy P
authors: TP
authors: Robbins
mesh_terms: D000483:Alleles; D000595:Amino Acid Sequence; D018744:DNA, Plant / Q000235:genetics; D004171:Diploidy; D019143:Evolution, Molecular; D035264:Flowers / Q000235:genetics; D014644:Genetic Variation; D005838:Genotype; D010641:Phenotype; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics*; D054817:Pollination; D012260:Ribonucleases / Q000235:genetics*; D060436:Self-Incompatibility in Flowering Plants / Q000235:genetics*; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D032322:Solanum / Q000201:enzymology / Q000235:genetics; D011198:Solanum tuberosum / Q000201:enzymology / Q000235:genetics*
chemical_list: D018744:DNA, Plant; D010940:Plant Proteins; D012260:Ribonucleases; C022542:ribonuclease S