MicroRNA regulation of gene expression under drought stress acclimation response in peanut (Arachis hypogaea L.) roots

Drought is one of the major devastating abiotic stress factors that affects crop productivity throughout the world. Plants tend to develop mechanisms to combat these adverse conditions. Some of these mechanisms are post transcriptionally regulated by short non-coding microRNA that directly modulate the gene expression during stress. The aim of this study was to identify the differentially expressed microRNAs and their targets having a significant role in drought stress and in acclimation in C76-16 drought tolerant peanut genotype. The mRNA and miRNA from root tissues were isolated and transcriptome profiles were generated by Illumina sequencing on HiSeq 2500 and MiSeq platforms respectively. A total of 800 million, 108bp reads representing the mRNA and 18 million, 35bp reads from miRNA sequencing were generated. A total of 3679 differentially expressed mRNA contigs and 350 differentially expressed microRNA were identified in response to drought acclimation. mRNA and miRNA expression profiles were analyzed and were found to be inversely correlated. MicroRNA-target analysis revealed that some of the drought stress and acclimation responses were mediated by these non-coding miRNAs. The microRNA target genes were mainly involved in redox reactions, transport, cell wall modifications and in transcription during drought stress and acclimation. Root transcriptome analysis revealed that auxin played a major role in lateral root formation during drought stress acclimation while drought stress responses were mediated by abscisic acid which is involved in inhibition of lateral root growth. More importantly, we found hormone signaling switch from abscisic acid (ABA) to auxin was observed during drought stress acclimation. This unique combinatorial study involving microRNA-mRNA expression will help in successful identification of molecular mechanisms that will assist in breeding improved drought tolerance in peanut.

Embargo status: Restricted until 09/2022. To request the author grant access, click on the PDF link to the left.