Mapping the microRNA Expression Profiles in Glyoxalase Over-expressing Salinity Tolerant Rice

Abstract: In the recent years, glyoxalase pathway has been an active area of research in both human and plants. This pathway is reported to confer stress tolerance in plants, by modulating the glutathione homeostasis to achieve detoxification of a potent cytotoxic and mutagenic compound, methylglyoxal. The microRNAs (miRNAs) are also reported to play significant role in stress tolerance for plants. However, the cross-talk of miRNAs with the metabolism regulated by glyoxalase in the salinity-tolerance is unexplored. We therefore investigated whether expression profiles of miRNAs are altered in response to glyoxalase overexpression, and if any of these are also responsible for modulating the stress responses of plants. In this study, the Next Generation Sequencing (NGS) was employed to profile miRNA expression levels from glyoxalase overexpressing transgenic lines. The associated targets of differentially expressed miRNAs were predicted and their functional annotation was carried out using Gene Ontology (GO) and KEGG Orthology (KO), which showed their involvement in several crucial biological pathways. The analysis of NGS datasets also identified other isoforms or isomiRs of selected miRNAs, which may have an active role in developing tolerance against salt stress. Different aspects of miRNA modifications were also studied in glyoxalase overexpressing lines.