Professor Hungarian University of Agricultural and Life Sciences, Godollo Budapest - XI. kerület, Pest, Hungary
Body of Abstract: FallingStones (FaSt) transposon was identified as a Mutator-type miniature inverted-repeat transposable element, preferentially accumulating in the euchromatin segments of the Prunus (stone fruits) genome and inducing self-compatibility (SC) in apricot. This study was carried out to check if FaSt copies are present in the transcriptome of different tissues of Prunus species. First, an in silico analysis of all available Prunus transcriptomic datasets was carried out and the complete FaSt sequence was identified in 9, 11 and 11 mRNAs of P. armeniaca, P. dulcis and P. persica, respectively. From the total of 31 complete FaSt copies, 28 and 2 were in the 3’ and 5’ UTRs, respectively, and one was located in a cytochrome P450 enzyme encoding gene. When genomic sequences were studied in Prunus species, many FaSt copies were identified in the promoters and introns of several genes, coding for proteins with diverse functions, including stress defense, metabolism, and signal transduction. Based on the small RNA and mRNA sequencing of apricot anther tissues, we compared the gene expression pattern in self-compatible (hetero- or homozygous for the highly expressed S-haplotype-specific F-box gene containing a FaSt insertion) and incompatible (free from a FaSt insertion in the SFB gene) apricot cultivars. In the anthers, 17 and 31 genes were up- and down-regulated in SC cultivars. Many small RNAs of 24-nt length were mapped on the FaSt sequence in leaf, while much fewer were detected in the anther. We identified a downregulated gene in the anthers of the SC cultivar that might be a target of FaSt-derived microRNAs. It still needs verification, but our results cannot rule out the possibility of a more sophisticated regulatory role of FaSt in the Prunus genome.
This study was supported by the NKFI K_128874 project.