Micrornas em alface (Lactuca sativa): novas descobertas sobre a regulação gênica pós-transcricional

Abstract

MicroRNAs (miRNAs) are small non-coding RNAs involved in the post-transcriptional regulation of gene expression in plants, participating in processes related to development, metabolism, and responses to biotic and abiotic stresses. Despite the biological relevance of these regulators, there is still limited information regarding the components of the miRNA processing pathway in Lactuca sativa L., one of the most economically important leafy vegetables worldwide. Therefore, this study aimed to identify and characterize proteins involved in miRNA biogenesis, as well as to predict and analyze conserved miRNA families in L. sativa cv. Salinas and L. sativa var. angustana. The analyses were performed through genome mining, multiple sequence alignments, conserved domain prediction, thermodynamic analyses, and phylogenetic inference using orthologous sequences from plant species. Additionally, 193 mature miRNA sequences (3p and 5p) and 137 precursor miRNAs were identified, distributed among 36 distinct miRNA families. The precursors exhibited stable secondary structures and thermodynamic parameters compatible with true miRNAs. Overall, the results obtained expand the current knowledge regarding the miRNA processing pathway in lettuce and provide an important basis for future functional studies related to gene regulation, plant development, and biotechnological applications aimed at crop improvement.