miRNome

MicroRNAs in plants are endogenous small non-coding RNAs involved in many biological processes related to growth, development and stress response, through post-transcriptional silencing of key target genes. Only a few studies have described the miRNome of globe artichoke. In a very first attempt, 122 new miRNAs were mined through miRNA transcriptomic analysis in leaves and roots of young plants in a NaCl treatment experiment. Computational approach based on known miRNAs sequences was adopted to predict candidate miRNAs in the reference genome sequence, while the recent resequencing of four globe artichoke and one cultivated cardoon genotypes has allowed to expand the prediction of high confidence miRNA-coding sequences. Although many plant microRNAs are evolutionary conserved, polymorphisms exist in many loci affecting miRNA biogenesis, function and target recognition, with a possible effect on phenotype. The existing variation observed in the globe artichoke germplasm could explain the variable number of predicted miRNAs and related target genes, across the tested genotypes and could be exploited in the future as a source of genetic variation for future crop improvement.