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Title:	Transcriptome profiling of drought stress in upland and lowland rice and functional studies OsMST6 gene in trangenic arabidopsis
Authors:	Monfared Hossein Hosseini (P54914)
Supervisor:	Zamri Zainal, Prof. Dr.
Keywords:	Universiti Kebangsaan Malaysia -- Dissertations Dissertations, Academic -- Malaysia Horticultural crops -- Effect of stress on Plants -- Effect of stress on -- Genetic aspects Plants -- Effect of stress on -- Molecular aspects.
Issue Date:	30-Aug-2017
Description:	Abiotic stresses, especially drought negatively influence biomass production and crop yield. Rice is known as a staple food crop for more than 50% of human population in the world. The drought-tolerance versus drought-sensitive traits have evolved in the upland and lowland rice, respectively. This makes interesting to study the molecular mechanisms of drought resistance using these genotypes with contrasting drought tolerance traits. In this study, we identified genes that differ in its expression pattern between the upland and lowland rice through a genome-wide transcriptome analysis using cDNA-AFLP technology. Three rice cultivars, Oryza sativa L. spp. indica cv. KUKU (upland), cv. MR84 (lowland) and cv. MR219 (lowland) were treated with 20% polyethylene glycol (PEG) and employed in cDNAAFLP profiling. In total, 40320 transcript derived fragments (TDFs) obtained from 64 primer combinations, among which 112 differential expression patterns with of 200- 600 bp in size were selected, cloned and sequenced. Seventy eight (69%) TDFs produced efficient match to reliable sequences, of which 112 TDFs were identified and annotated through homology search using BLASTX against the GenBank and Rice Genome Annotation Project Database. The majority of differences between tolerant and sensitive rice cultivars were found to be related to genes involved in cell growth/division, disease/defiance and secondary metabolites. Validation of the expression pattern of three selected genes which encode PP2C, MST6 and FACT proteins were carried out through qRT-PCR..The qRT-PCR results are in accordance with data obtained from the selected TDFs of cDNA-AFLP profiling. Several stress related genes were identified, among which OsMST6 encoding monosaccharide transporter 6. OsMST6 was selected for functional studies. Transformation vector harboring OsMST6 driven by 35S promoter was constructed using Gateway technology and transformed into Arabidopsis thaliana via floral dip technique. From initial screening under 200 mg/L Basta, forty-two independent transgenic lines were obtained and verified by PCR. For characterization experiments, five T3 homozygous transgenic lines were randomly selected and subjected to stress experiments. Altered tolerance to drought stress was observed in these lines. Transgenic Arabidopsis overexpressed OsMST6 indicated lower water loss rate, higher relative water content (1.3- 2.5-fold), biomass (1-1.3-fold), cell membrane stability (1.5-2-fold) and total soluble sugars (1-3.5-fold). The results showed that over-expressed OsMST6 increased tolerance to drought, salt, cold, and freeze stresses in Arabidopsis, thus OsMST6 most likely plays important role as a regulatory element involved in a multiple stresses responsive pathway. This study is providing insight into OsMST6 function, which could have high potential application in generation of transgenic abiotic stress tolerant plant.,"Certification of Master's / Doctoral Thesis" is not available,Ph.D
Pages:	163
Call Number:	QK754.M636 2017 tesis
Publisher:	UKM, Bangi
Appears in Collections:	Faculty of Science and Technology / Fakulti Sains dan Teknologi

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