Ali Asghar Dehghan - Department of Plant Protection, School of Agriculture, Shiraz University
Ali Moghadam - Institute of Biotechnology, Shiraz University, Shiraz, Iran
Akbar Karegar - Department of Plant Protection, School of Agriculture, Shiraz University
Yaser Miniaz - Plant Virology Research Center, Shiraz University, Shiraz, Iran
Fateme Amiri - Department of Plant Protection, School of Agriculture, Shiraz University

Drought is one of the major environmental risks that decreases the successful production of crops, especiallyrice, in the world, which can occur at any time during the growing season. Hence, one of the main challengesin agriculture is to produce more food with less water. Therefore, study of molecular mechanisms in order tocharacterization of key gene networks responsive to this stress is more considered. For this purpose, weretrieved the transcriptome RNA seq data from the European Bioinformatics Institute (EBI) database. Dataquality analysis and final analysis were performed using CLC Genomics Workbench ۲۰.۰. The referencegenome as well as the rice annotation were downloaded from the NCBI. Adjusted P-values (FDR < ۰.۰۰۱)were considered significant and, differentially expressed genes (DEGs) were used for further analysis.Analysis of GO enrichment for DEGs showed that transcripts were more involved in cellular processes suchas cellular process and localization. In addition, In the category of cellular components, DEGs were enrichedfor cellular anatomical presence and intracellular anatomical structure. In the category of molecular functionmost genes were referred to ion membrane transmitter activity, transmembrane transporter activity ofmolecular entity. Based on the results of Kyoto Encyclopedia of Genes and Genomes analysis, it wasconcluded that endocytosis and mRNA surveillance pathways, these two had a greater role in the plant'sresponse to drought stress. In microRNA analysis, miR۱۵۶, miR۱۶۰, miR۱۷۱, and miR۱۷۲ showed thehighest expression in drought stress conditions. In the analysis of transcription factors, it was shown that thebHLH family had the highest expression in both down-regulated and up-regulated genes in response todrought stress. Also, transcription factors bZIP, WRKY, MYB, C۲H۲, which play a key role in droughtresistance and stress, had the highest increase in expression.

Key words: Abiotic stress, microRNA, System biology, Drought