CONICET | Buscador de Institutos y Recursos Humanos

Micro RNAs (miRNAs) are small single strand non-coding RNAs that regulate gene expression at the posttranscriptionallevel, either by translational inhibition or mRNA degradation based on the extent ofcomplementarity between the miRNA and its target mRNAs. Potato (Solanum tuberosum L.) is the most importanthorticultural crop in Argentina. Achieving an integrated control of diseases is crucial for this crop, where frequentagrochemical applications, particularly fungicides, are carried out. A promising strategy is based on promotinginduced resistance through the application of environmentally friendly compounds such as phosphites, inorganicsalts of phosphorous acid. The use of phosphites in disease control management has proven to be effective. Althoughthe mechanisms underlying their effect remain unclear, we postulated that miRNAs could be involved. Therefore weperformed next generation sequencing (NGS) in potato leaves treated and non- treated with potassium phosphite(KPhi). We identified 25 miRNAs that were expressed differentially, 14 already annotated in miRBase and 11 mappedto the potato genome as potential new miRNAs. A prediction of miRNA targets showed genes related to pathogenresistance, transcription factors, and oxidative stress. We have also analyzed in-silico stress and phytohormoneresponsive cis-acting elements on differentially expressed pre miRNAs.Despite the fact that some of the differentially expressed miRNAs have been already identified elsewhere, this is toour knowledge the first report identifying miRNAs responsive to a biocompatible stress resistance inducer such aspotassium phosphite, in plants. Further characterization of these miRNAs and their target genes, might help toelucidate the molecular mechanisms underlying KPhi-induced resistance. This might, in turn, aid in the design ofgenetically engineered potatoes to achieve a product with enhanced resistance to environmental stress.