Dissertation > Excellent graduate degree dissertation topics show

MicroRNA Transcriptomic Analysis of Heterosis during Maize Seed Germination

Author: WangYinJu
Tutor: HuYanMin
School: Henan Agricultural University
Course: Crop Genetics and Breeding
Keywords: Maize Heterosis MicroRNA Deep sequencing Maize seed germination Regulation of gene expression
CLC: S513
Type: Master's thesis
Year: 2013
Downloads: 59
Quote: 0
Read: Download Dissertation

Abstract


Maize is an important food, economic and forage crop, and heterosishas been utilized widely in maize breeding for a long time, but the molecular mechanismresponsible for heterosis is far from clear. Therefore, to clarify the molecular mechanismof heterosis will play an important role on the molecular breeding in maize.MicroRNAs (miRNAs) is newly identified class of20-24nt non-protein-codingand endogenous small RNAs. This non-protein-coding RNAs are highly conserved in allkinds of animals, plant and microbial species. MicroRNA regulate gene expressionmainly at the transcriptional and post-transcriptional level, which plays an important rolein regulating plant growth, development and response to environmental stresses in plants.Therefore, it is urgent to search for important miRNAs correlating with heterosis duringmaize seed germination and preliminarily reveal the molecular mechanism of heterosis.In previous study, we find that maize germination is affected less by externalenvironment, and express a strong heterosis, so it is a good direction to study heterosisin maize. In this study, one hybrid maize Yuyu22and its two parents87-1and Zong3were utilized for dissecting the genetic basis of heterosis with miRNA regulation, whichis an elite hybrid widely cultivated in China that exhibits high heterosis for grain yield.The significant miRNAs expressed differently amount between the hybrid and itsparental lines were got through Solexa high throughput sequencing, and the target geneswere predicted by bioinformatics methods. The important candidate miRNAs and targetgene which related to the heterosis were analyzed and validation with Real-time PCR.The main results of this study were as follows:Ten million reads small RNA were got by Solexa sequencing (reads per million). Intotal,107known miRNAs belonging to21miRNA families were co-detected in thehybrid and its two parental lines, and most (94/107) of the miRNAs were differentially(non-additively) expressed in the germinating embryos between the hybrid and theinbred lines.There were1068small RNAs in the inbred line87-1that did not match conservedmiRNAs, but was located within a stem-loop structure with their flanking sequence. TheMFEI (minimal folding free energy index) of all1068miRNA candidates werecalculated and searched in other samples to confirm whether they were true miRNAs.Thirty-four miRNAs were most likely true novel miRNAs, which have not yet beenreported.The target genes of these34newly defines miRNAs were predicted by the targetgene prediction software online-psRNATarget. A total of408unique miRNA targets were detected. These target genes were further analyzed by GO (Gene Ontology), andmost of them were concentrated on transcriptional and translational regulators. Some ofthem were involved in the metabolic pathways processes, such as transcriptionregulation, substance and energy metabolism, stress response, and signal transductionthrough further function prediction.Expression profiles were established based on real-time RT-PCR analysis of sixselected conserved miRNAs and eight novel miRNAs, as well as real-time RT-PCRanalysis of their target genes. The differential expression of miRNAs showed that thesequencing data accorded well with the real-time RT-PCR reactions, which show thereliability of the sequencing results.Combined present results with previous studies on the model plant and analyzed ofdifferentially expressed microRNAs, it was speculated that the differentially expressedmicroRNAs regulated the expression of their target genes between hybrid and parentallines to affect heterosis during maize seed germination. So, the facts that most of themiRNAs were repressed in the hybrid compared to the parental inbred line, whichpossibility be one of the causes of its heterosis performance.

Related Dissertations

  1. Research and Application of Diverse Density Learning Algorithm,TP181
  2. Effect of Planting Densities and Modes on Lodging Resistance of Stem in Summer Maize,S513
  3. The Effects of Abaand H2O2 on sHSPs and Antioxident Defense Enzymes Induced by the Combination of Drought and Heat Stress in Maize,S513
  4. Studies on Senescence Difference in Roots and Leaves in Two Varieties of Maize and Their Regulator,S513
  5. Optimization Design Andapplication of Extracting Methods of Maize (Zea Mays L.) Volatile Compounds,S513
  6. The Difference of Proteome Expression of Low Light Stress and Regular Light Recovery on Growth of Maize Seedling,S513
  7. Effect of Nitrogenapplication Patterns on Variation of Soil Nitrate-N and Grain Yield of Wheat and Maize,S512.11
  8. Primary Study of Inheritance on Lodging Resistance Traits in Maize,S513
  9. Identification and Preliminary Study of a New Ecological-sensitive Genic Male Sterileline in Maize,S513
  10. Bioinformatics Study of Motifs Within 3’UTR Region of Stress Response Genes and Functional Related Mirnas in Rice,Q943.2
  11. Computational Identification and Characterization of Microrna Genes from Agricultural Insects,S186
  12. Screening and Isolation of One γ-PGA Producing Bacterium and Bilogical Effect of Bio-Organic Fertilizer,TQ922.1
  13. Characterization of Mineral Phosphate-Solubilizing Bacterium K3 and Colonization under Different Soil,S144.9
  14. Studies on the Residues of Bromoxynil and Mesotrione in Maize and Soil,S481.8
  15. Difference Analysis of Growth and Photosynthetic Characteristics in Six Maize Lines and Hybrids Via a Diallel Design,S513
  16. Monitoring Nitrogen Status and Growth Characters with Canopy Spectral Reflectance in Summer Maize,S513
  17. Study on Heterosis and Genetic Basis of Soybean,S565.1
  18. Cloning and Characterization of Photoperiod Sensitive Gene ZmELF4 in Maize,S513
  19. Fine Mapping of Two Leaf Mutant Genes al and yl in Maize,S513
  20. Identification and Analysis of miRNA and Flower Development Specific Genes in Wheat,S512.1
  21. Effect of in Ovo Leptin Administration on Hepatic Expression of Genes and Micrornas Involved in Cholesterol Metabolism in Broiler Chickens,S831

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