Role of microRNAs in regulating drought stress tolerance in maize

Abstract

Maize is one of the most important crop all over the world. One of the major abiotic stress is drought that reduces the productivity of maize. Plants have many mechanisms to combat with the serious drought effects and one of the defense mechanism is the reprogramming the gene expression by microRNAs. miRNAs are the non-coding 20-22 nucleotide length that have emerged as important regulators of gene expression at post-transcriptional level. In this study the differential expression of microRNAs in drought tolerant lines was detected. Seven families of microRNAs have been selected for study. The target genes of the miRNAs have been found out by using online tools psRNA Target and RNA hybrid. A total of seven microRNAs targeting 16 mRNAs were predicted. The hypothesis that selected microRNAs differentially expressed to drought stress was validated by qRT-PCR. Under drought stress, the differential expression of microRNAs regulates the expression of their target genes, resulting in multiple responses of physiological and biochemical pathways relative to drought tolerance of maize. miR160, miR164, miR166, miR393, miR529, miR169 and miR2275.families may play more important role. The different members of the same family may play similar regulation effects in most cases.