Abstract

Adikeshavan Thilagavathy and Varadahally Rangaiah Devaraj

Post-transcriptional regulation of gene expression via microRNAs (miRNAs) plays crucial role in plant responses to environmental changes. Hyacinth bean, a versatile adapter to drought conditions, exhibited miRNA mediated regulation of gene expression in tissue-specific manner as revealed by Reverse Transcription quantitative PCR (RT-qPCR). Contrasting expression pattern of two miRNAs; miRNA167 and miRNA393 in root and leaf tissues suggested different targets and functional divergence of miRNAs within the same species. Target prediction and gene annotation showed that majority of the target genes included transcription factors involved in plant growth, development and stress responses. Membrane transporters, metabolic enzymes, antioxidant enzymes and components of miRNA biogenesis were other predicted targets, suggesting the crucial roles of these miRNAs in diverse physiological functions under drought stress. Considering the expression pattern of drought responsive miRNAs and functional annotation of their predicted targets a possible regulatory network operating in roots and leaves of hyacinth bean, contributing to signal transduction pathways for osmotic homeostasis, and antioxidant defense is proposed.