microRNAs as promising tools for improving stress tolerance in rice.

Rice (Oryza sativa) represents one of the most important food crops in the world, since it feeds more than two billion people. The increased rice production can play significant roles in upgrading the economic status of countries like India and China. A great deal of research has been carried out in the recent past on the molecular biology, genomics and biotechnology of rice. By employing recombinant DNA technology, remarkable progress had been made towards production of rice plants with increase yield, improved nutritional quality and resistance to various diseases. Under these circumstances, the study of microRNAs can contribute to new discoveries in this field. The miRNAs are assign to modulate gene expression at the post-transcriptional level. They are small, non-coding, single stranded RNAs that are abundantly found in prokaryotic and eukaryotic cells and can trigger translational repression or gene silencing by binding to complementary sequences on target mRNA transcripts. In the recent years, miRNAs have been reported to control a variety of biological processes, such as plant development, differentiation, signal transduction or stress responses. The present review provides an up-date on microRNAs and their involvement in the stress response in rice. A section is specifically dedicated to the genetic engineering perspectives regarding the miRNAs applications in rice tolerance to stress conditions.