GENOME-WIDE microRNA IDENTIFICATION IN DROUGHT TOLERANT WILD EMMER WHEAT
Reyyan Fatima Bulut
Molecular Biology, Genetics and Bioengineering Department, MSc. Thesis, 2016
Prof. Dr. Hikmet Budak (Thesis Advisor), Asst. Prof. Dr. Bahar Soğutmaz Özdemir, Asst. Prof. Dr. Burcu Saner Okan
Date & Time: 15th, 2016 – 10:30 AM
Place: FENS L065
Keywords : microRNA, drought, Triticeae, wheat, emmer wheat, in silico analysis, RT-qPCR
As the progenitor of A and B genomes of hexaploid bread wheat, wild emmer wheat (Triticum turgidum spp. dicoccoides) is the source of genes that are involved in several biotic and abiotic stress responses. It constitutes a rich genetic resource for the improvement of common wheat which has lost its stress resistance traits as a trade-off to high yield and quality due to years of cultivation and selection practices. Thus, untangling the genetic elements involved in the stress-response metabolism in the wild progenitors and exploitation of this genetic diversity holds great importance. microRNAs (miRNA) are small non-coding RNAs which post-transcriptionally regulate many vital cell metabolism pathways in plants across diverse tissues and stress conditions. miRNA mediated drought response of wheat have been investigated in a number of studies and the miRNA over-expression studies of other cereal species are giving promising results towards development of drought tolerant crops. In this study, we utilized the 10.8 Gb whole genome shot-gun assembly of Zavitan, a highly drought tolerant wild emmer wheat accession, to computationally identify its putative miRNAs, repeat-related fold-back structures and tRNAs. After constructing a wheat expression database, we have searched the identified miRNA precursors in it for the in silico expression evidence. Furthermore, expression of randomly selected mature miRNAs was demonstrated with RT-qPCR. To further investigate the involvement of these miRNAs in drought metabolism, we comparatively screened their stress induced expression profiles in root and leaf tissues across two different shock drought stress durations. In addition to exploring the miRNA repertoire of the wild emmer wheat, our results have delineated spatio-temporally changing drought-responsive miRNA profiles, bringing forth new miRNA gene candidates for future crop improvement studies.