Dissertation > Excellent graduate degree dissertation topics show

Functional Identification of Two Tomoto Phosphater Transporter Genes LePT1 and LePT2 in Rice

Author: HongShuai
Tutor: XuGuoHua
School: Nanjing Agricultural College
Course: Plant Nutrition
Keywords: Rice Phosphate transporter LePT1 LePT2 Gene expression
CLC: S511
Type: Master's thesis
Year: 2011
Downloads: 13
Quote: 0
Read: Download Dissertation

Abstract


Phosphorus (P) is one of the essential macronutrients for plant growth and development. It plays key roles in plant metabolic processes, such as energy transfer, signal transduction, biosynthesis of macromolecules. The primary source for P uptake by transporters of plant roots is inorganic phosphate (Pi) in soils. Pi mobilization is very low in soils due to microbial and metal ion fixation. Plants have evolved several strategies to improve Pi acquisition, including alterations in root morphology, modification of soil chemical properties around the roots, formation of symbiotic associations with arbuscular mycorrhizal (AM) fungi and activation of high-affinity Pi transporters.Molecular breeding of high Pi use efficient crops by exploitation and transformation of the key genes regulating Pi acquisition and utilization has become one of the hotest research topics in current plant biology. It is known that plants use specific Pi transporters (Pht) in the roots to take up Pi from soil solution and Pi translocation within the plants. So far, most of the identified Pht members in plants belong to putatively high affinity Pht1 family. Previous researches had shown that LePT1 and LePT2 are two tomato Phtl genes regulated by Pi-starvation.In this study, we first cloned LePT1 and LePT2 from tomato genome, then expressed them in a rice cultivar (Nipponbare) through the transgenic technology with the Agrobacterium tumefaciens. The bio-informatics of the gene sequences and physiological analyses of the transgenic rice showed the following results:1. The cluster analysis of the predicted amino acid sequences and transmembrane domains demonstrated that LePT1 and LePT2 are highly conserved in the structure and functional site with 13 members of Pht1 family in rice genome. They show the highest similarity with Pi-starvation regulated rice Pi transporters, OsPT2 and OsPT4, respectively. 2. Semi-quantitative RT-PCR analyses indicated that the respective abundant transcript levels of tomato LePT1 and LePT2 driven by the constitutive promoter CaMV35S in both roots and shoots of the individual transgenic lines of rice. Interestingly, the expression of either LePT1 or LePT2 did not affect the transcript levels of each endogenous Phtl members in the rice.3. Four independent transgenic lines of rice with expression of LePTl and LePT2 were selected for analyzing their responses to Pi starvation and sufficient supply in comparison to the non transgenic rice (WT). Expression of either LePT1 or LePT2 in the rice resulted significant increases of water extractable and total P concentrations, plant height and biomass yield at low Pi supply condition. However, the transgenic rice accumulated very high P concentrations in comparison to WT at high Pi supply condition, which might be the cause of relative smaller size and less tiller number by the constitutive expression of LePT1 and OsPT2.Taken together, the resulted confirmed that both LePTl and LePT2 have the functions of Pi uptake and translocation, the Phtl members from di-cotyledons could be directly used for improving Pi use in mono-cotyledons through molecular genetics approach.

Related Dissertations

  1. Research on Combinatorial Regulation of Multiple Transcription Factors,Q78
  2. The Expression Survey of BMP Signalling Pathway in the Human Embryonic Tooth Germ,R78
  3. SCXC corporate culture construction,F270
  4. Monitoring of Insecticide Resistance and Resistance Risk Assessment for JS118 in the Rice Stem Borer, Chilo Suppressalis (Walker),S435.112.1
  5. Arthropod Diversity in Non-Crop Habitats at Margins of Paddy Fields of Different Types,S435.112
  6. Detection of the Resistance in Xanthomonas Oryzae PV. Oryzae and X. Oryzae PV. Oryzicola to Two Bactericides and the Assentment of Resistance Risk in Vitro,S435.111.4
  7. Study on Application of Red Yeast Rice in Fermented Sausage,TS251.65
  8. The Research on Improvement of Rice Noodles Quality,TS213.3
  9. Studies on the Properties of Starch from Germinated Polished-rice-with-germ,TS235.1
  10. The Research on the Comprehensive Modification Technology of Rice Protein Enzymatichydrolysis and Graft Copolymerization,TS201.2
  11. The Rice OsNAR2.1 Participates the Regulating Root Growth by Nitatre,S511
  12. Research on Feed Safety of Transgenic Rice in Broiler,S831.5
  13. Study on Synthesis and Physiological Function of N-carbamoyl-glutamate,R914
  14. Soil Eoclogical Risk Evaluation of Transgenic Bt Rice Through Nematode Community Analysis,S154.1
  15. Genetic Analysis and Molecular Mapping of QTL for Rice Black-Streaked Dwarf Disease Resistance in Rice,S511
  16. Detection of Exogenous Recombinan DNA of Transgenic Rice and Its Rice Product,S511
  17. Concentrations of Lipids in Grains of Japonica Rice: In Response to Nitrogen Fertilizer and in Relation to Physicochemical Properties of Rice Flour,S511.22
  18. Genetic Segregation Analysis and QTL Mapping as Well as Association Analysis for Panicle Angle Trait in Japonica Rice (Oryza Sativa L.),S511.22
  19. Functional Analysis of Two Rice Nitrate Transporter Genes OsNRT1.1a and OsNRT1.1b,S511
  20. Characteristics of Over-Expression for Nitrate Transporter Genes OsNRT1.2 and OsNRT1.5 in Rice,S511
  21. Coparative Analyses of Carbon and Nitrogen Metabolism of Flue-cured Tobacco Growing in Henan and Yunnan,S572

CLC: > Agricultural Sciences > Crop > Cereal crops > Rice
© 2012 www.DissertationTopic.Net  Mobile