Micro RNAs and nitric oxide cross talk in stress tolerance in plants

Modern agriculture is facing significant challenges due to the high complexity of field conditions caused not only by currently ongoing global climatic change but also by stress combinations. Recent research is focusing on the molecular mechanisms controlling stress responses in plants. Many efforts have been made to uncover the complex but well-coordinated stress responsive mechanisms, mainly stress responsive protein-coding genes. The discovery of microRNAs (miRNAs) as gene regulators has shed light on post-transcriptional gene regulation in plants. miRNAs are regulators of plant growth and development and are also master players in plant stress responses, as evidenced from the expression profiles of most of miRNAs that altered during stress. These facts reveal that under stress conditions, plant growth and development may be under the control of stress-responsive miRNAs. In addition, nitric oxide (NO) has also been identified as a promising candidate in cellular signalling by modulating gene expression and protein activity, particularly by transcriptional and post-translationally modifying proteins. Many studies have been carried out to uncover the role of miRNAs as well as NO in plant stress responses individually, but their interactive mechanisms are little reported. In this review, we have compiled current updates on miRNA and NO signalling along with their cross-talk under stress conditions in plants.