INVOLVEMENT OF PLANT MICRORNAS IN ABIOTIC STRESS RESPONSES

Abstract

Crop production is constrained by several biotic and abiotic stresses. Several techniques have been applied by different research groups to unravel the molecular mechanism of tolerance to these stress factors in plants. Recently micro- RNAs have contributed towards understanding the role of micro-RNAs under abiotic stress conditions. Through first reported in animals its abundance in found in plants even with some difference in biogenesis and mechanism of target gene regulation. However, the relationship between micro-RNAs and stress responses is just beginning to be explored. Micro-RNAs are about 21-24 nucleotide single stranded non coding RNA often conserved across species suggesting their evolutionary significance. MiRNAs are either up or down regulated under stress
conditions suggesting their involvement in gene expression regulation by post transcriptional degradation or translational repression in plants. A major category of MiRNA target gene consists of transcription factors or other regulatory proteins that function in plant development or signal transduction. One our own research endeavour in this direction revealed the role of MiRNA towards salinity stress response in sugarcane. Several researches worldwide is leading to the identification of thousands of miRNAs, the functional validation of which will help in designing new strategies for improving tolerance to biotic and abiotic stresses. The current review gives the recent status of micro-RNA research towards its role under abiotic stress.