Dissertation > Excellent graduate degree dissertation topics show

Differential Expression of MicroRNAs under Drought Stress in Maize

Author: LiJingSheng
Tutor: LiWanChen
School: Sichuan Agricultural University
Course: Biochemistry and Molecular Biology
Keywords: Drought MicroRNA Target gene Differential expression Maize(Zea mays L.)
CLC: S513
Type: PhD thesis
Year: 2013
Downloads: 268
Quote: 0
Read: Download Dissertation

Abstract


Plants growth and development were affected by drought, which is the most important abiotic stress factors restricting agricultural production. Maize is the dryland crop of largest water requirement, more sensitive to drought stress. With global warming and increasing scarcity of water resources, the yield of maize often seriously losses because of the drought. So drought tolerance improvement of maize breeding is particularly important.Drought tolerance in maize is a complex quantitative trait controlled by multiple genes, which needs to be identified in a specific environment, using the conventional method in screening drought tolerant varieties is so slow and less efficient. With the development of molecular biological technology, we have provided the powerful technical support for the research of drought tolerance in maize. Recent studies show that, microRNAs is closely related to the plant drought tolerance, to affect affect plant phenotypes of drought-tolerance by regulating the expression of their target genes under adversity stress. Detecting the differencial expression of microRNAs and their target genes in maize under drought stress, which can provide reference for the molecular genetic research on plant drought tolerance.According to a previous evaluation for drought tolerance, taking maize drought-tolerant inbred line of "81565","87-1" and drought-sensitive inbred line of "21ES","Dan340" as the material in this study, extracting and isolating small RNAs after treating the seedlings with polyethylene glycol6000(PEG-6000) simulative drought treatment, through the microRNA microarry hybridization technology to analyse differential expression of microRNAs in4different drought-tolerance inbred lines under drought stress. Predicting their target genes with WMD3software, and analysing their possible roles in drought response by corn functional annotation database. Analysing mRNA of4maize inbred lines through same treatment by digital expression profiling, compared to target genes regulated by differentially expressed microRNAs, and analysing the regulation modes under drought stress. Detecting differential expression of the miR159and miR168 in4maize inbred lines with LNA-Northern Blotting technology, which play key roles at seedling stage drought stress response pathways upstream.The main results are as follows:1. Analysis of small RNA under drought stress in4different drought-tolerance inbred lines through the microRNA microarry hybridization showed that303microRNAs were identified to be differentially expressed at the1%significant level.185out of which belong to20maize microRNA families (including2microRNAs from custom21new microRNAs),118out of which can be classified into43microRNA families from other11species. But among different maize inbred lines, even different time points from the same inbred line, the expression amount of the microRNAs were not alike. According to the results of cluster analysis, the expression patterns can be divided into8modes: up-regulated or down-regulated expression in the whole process under drought stress; induction or inhibition of expression in the early stage of drought stress, and then returned to normal levels in the later stage; up-regulated or down-regulated expression has been delayed in the late stage of drought stress; up-regulated or down-regulated expression in the early stage of drought stress, in the later stage, but on the contrary in the later stage.2. Taking WMD3software to predict the target genes regulated by microRNAs of drought stress response,128differentially expressed microRNA predicted390potential target genes.46microRNA families were predicted the target genes,21out of which were homologous with maize, and25out of which were nonhomologous with maize.3. Comparing digital expression profiling to target genes regulated by differentially expressed microRNAs show that in the process of each treatment of each inbred line, there were differential expression of predicted target genes. Making function analysis of GO annotation to target genes regulated by differentially expressed microRNAs, they can be divided into several categories according to the function:the genes related metabolism and growth, the enzymes involved in protein modification, the proteins involved in the transcription and translation, transmembrane transport proteins, transcription regulation factors, the signal transduction proteins, the proteins related stress resistant response, and some unknown function proteins.4. Conducting the the comprehensive analysis of the differential expression of microRNA and the differential expression of the target gene, found that in the same family microRNA can simultaneously control serveral multiple target genes, which also participates in the regulation of multiple physiological and biochemical pathways; and more than one family can also be combined with microRNA regulation of a target gene. And the study also disscussed and analysed the potential regulation mechanisms of miRl59, miR168, miRl64, miR165, and miR166under drought stress.5. Using the LNA-Northern blotting to confirm the differential expression of miRl59and miR168in4maize inbred lines. Test results are basically the same with microRNA microarray hybridization results, thus proving the reliability of the microarray data.

Related Dissertations

  1. Drought Stress on the Osmanthus Growth and Physiological Ecology Effect,S685.13
  2. Bioinformatics Study of Motifs Within 3’UTR Region of Stress Response Genes and Functional Related Mirnas in Rice,Q943.2
  3. Molecular Clonging and Functional Analysis of Heat Shock Transcriptional Factor CarHSFB2 in Chickpea (Cicer Arietinum L.),Q943.2
  4. Computational Identification and Characterization of Microrna Genes from Agricultural Insects,S186
  5. Anatomy of Root, Stem and Its Lignin Content and Expression of Related Key Genes in Lignin Synthesis of Lodging Resistant Brassica Napus L.,S565.4
  6. The cDNA-AFLP Analysis of Gene Differential Expression and RNA Editing of ATP6 Gene between Cytoplasmic Male Sterile Lines and Their Maintainer Lines in Soybean (Glycine max (L.) Merrill),S565.1
  7. The Comprehensive Appraisal of the Ornamental Value and Drought and Flooding Resistance of the Cultivars of Guoqing Chrysanthemum with Small Inflorescences,S682.11
  8. Gene Differential Expression and RNA Editing of atp9 between Soybean Cytoplasmic-Nuclear Male Sterile Lines and Their Maintainer Lines,S565.1
  9. Effects of the Double-Stock Grafting on the Physiological Characteristics, Yield and Quality of Cucumbers,S642.2
  10. The Effects of Abiotic Stress on Growth and Plant-plant Interaction between Three Sphagnum Species,Q945.78
  11. Epithelial-Mesenchymal Transition (EMT) and the Expressive Effect of Emt on microRNAs in Lung Cancer A549 Cells,R734.2
  12. Identification of Differently Expressed MicroRNA in Medulloblastoma and Function Analysis,R730.2
  13. Preliminary Study of MicroRNA Expression in Hippocampus of Rats with Cognitive Disorders After Traumatic Brain Injury,R651.15
  14. Physiological and Ecological Response of Soybean Seedlings to Drought and High Temperature under the Background of Climate Change,S565.1
  15. The Prediction of Micrornabased on Machine Learning,R346
  16. Study on the Role of Poly(ADP-ribose)polymerase-1 in the Transcriptional Regulation of Vitamin D Receptor in Rat Thoracic Aortic Smooth Muscle Cells,R541
  17. Construction and Identification of MicroRNA Eukaryotic Expression Vectors Targeting Vsacular Endothelial Growth Factor,R735.7
  18. Detection of the Expression Level of microRNA-140 (miR-140) in Knee Synovial Fluid of Osteoarthritis (OA) Patients Using Real-time Fluorescent Quantitative PCR,R684.3
  19. Construction of Mutant Strains (ΔnarQ/narP) and Function of Two-Component Regulatory System narQ/narP on Actinobacillus Pleuropneumoniae,S852.61
  20. Research on Improving Plant Persistence Drought Resistance by Inducible Pathways.,Q945
  21. Effects of Drought Stress on Physioecological Characteristics of Typical Plants in the Ecotone between Dry Valley and Mountain Forest,Q948

CLC: > Agricultural Sciences > Crop > Cereal crops > Corn ( maize )
© 2012 www.DissertationTopic.Net  Mobile