Allelic diversity of S-RNase alleles in diploid potato species
Tuesday, 2016/10/25 | 07:54:59
|
Daniel K. Dzidzienyo, Glenn J. Bryan, Gail Wilde, Timothy P. Robbins Theoretical and Applied Genetics; October 2016, Volume 129, Issue 10, pp 1985–2001 Key messageThe 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. AbstractS-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. Communicated by Y. Xue. See: http://link.springer.com/article/10.1007/s00122-016-2754-7
Fig. 5 Phylogenetic tree of S-RNases and S-like RNases. A phylogenetic tree of the 16 cloned S-RNases and selected S-like Rnases from Solanaceae. Three published S-RNases, one from each of Petunia, Nicotiana and Solanum chaoense (highlighted with a triangle) were included as reference sequences. Fungal RNase T2 of Aspergillus oryzae was included as an out-group to root the phylo-genetic tree. Numbers are bootstrap values expressed as a percentage and only those exceeding 50 % are shown. Bootstrap values were based on 1000 replicates. The phylogenetic tree was drawn using MEGA5 software. N.ala = Nicotiana alata, N.glu = Nicotiana glutinosa, N.tab = Nicotiana tabacum, S.lyc = Solanum lycopersicon, S.oka = Solanum okadae, S.phu = Solanum phureja, S.ste = Solanum stenotomum |
Back Print View: 556 |
[ Other News ]___________________________________________________
|