Molecular Genetics and Genomics

, Volume 276, Issue 6, pp 503–516

Genomic analysis of the rhg1 locus: candidate genes that underlie soybean resistance to the cyst nematode

  • E. Ruben
  • A. Jamai
  • J. Afzal
  • V. N. Njiti
  • K. Triwitayakorn
  • M. J. Iqbal
  • S. Yaegashi
  • R. Bashir
  • S. Kazi
  • P. Arelli
  • C. D. Town
  • H. Ishihara
  • K. Meksem
  • D. A. Lightfoot
Original Paper

DOI: 10.1007/s00438-006-0150-8

Cite this article as:
Ruben, E., Jamai, A., Afzal, J. et al. Mol Genet Genomics (2006) 276: 503. doi:10.1007/s00438-006-0150-8

Abstract

The rhg1 gene or genes lie at a recessive or co-dominant locus, necessary for resistance to all Hg types of the soybean (Glycine max (L.) Merr.) cyst nematode (Heterodera glycines I.). The aim here was to identify nucleotide changes within a candidate gene found at the rhg1 locus that were capable of altering resistance to Hg types 0 (race 3). A 1.5 ± 0.25 cM region of chromosome 18 (linkage group G) was shown to encompass rhg1 using recombination events from four near isogenic line populations and nine DNA markers. The DNA markers anchored two bacterial artificial chromosome (BAC) clones 21d9 and 73p6. A single receptor like kinase (RLK; leucine rich repeat-transmembrane-protein kinase) candidate resistance gene was amplified from both BACs using redundant primers. The DNA sequence showed nine alleles of the RLK at Rhg1 in the soybean germplasm. Markers designed to detect alleles showed perfect association between allele 1 and resistance to soybean cyst nematode Hg types 0 in three segregating populations, fifteen additional selected recombination events and twenty-two Plant Introductions. A quantitative trait nucleotide in the RLK at rhg1 was inferred that alters A47 to V47 in the context of H297 rather than N297. Contiguous DNA sequence of 315 kbp of chromosome 18 (about 2 cM) contained additional gene candidates that may modulate resistance to other Hg-types including a variant laccase, a hydrogen-sodium ion antiport and two proteins of unknown function. A molecular basis for recessive and co-dominant resistance that involves interactions among paralagous disease-resistance genes was inferred that would improve methods for developing new nematode-resistant soybean cultivars.

Keywords

Disease resistance Nematode Heterodera Glycine Legume 

Supplementary material

438_2006_150_MOESM1_ESM.pdf (263 kb)
Supplementary material

Copyright information

© Springer-Verlag 2006

Authors and Affiliations

  • E. Ruben
    • 1
    • 2
  • A. Jamai
    • 3
    • 11
  • J. Afzal
    • 1
  • V. N. Njiti
    • 1
    • 5
  • K. Triwitayakorn
    • 1
    • 4
  • M. J. Iqbal
    • 1
  • S. Yaegashi
    • 1
    • 6
  • R. Bashir
    • 1
  • S. Kazi
    • 1
  • P. Arelli
    • 7
  • C. D. Town
    • 8
  • H. Ishihara
    • 10
    • 11
  • K. Meksem
    • 1
    • 9
    • 11
  • D. A. Lightfoot
    • 1
  1. 1.Genomics Core Facility and Center of Excellence in Soybean Research, Teaching and Outreach, Department of Plant, Soil and Agricultural SystemsSouthern Illinois University at CarbondaleCarbondaleUSA
  2. 2.National Center for Protein Structure AnalysisGainesvilleUSA
  3. 3.Department of Biological SciencesDartmouth CollegeHanoverUSA
  4. 4.Institute of Molecular Biology and GeneticsMahidol UniversityNakhon PathomThailand
  5. 5.Center for Plant Biotechnology and GenomicsAlcorn State UniversityAlcorn StateUSA
  6. 6.University of TokyoTokyoJapan
  7. 7.USDAJacksonUSA
  8. 8.The Institute for Genomic ResearchRockvilleUSA
  9. 9.Plants and Microbes Genomics and Genetics LaboratorySouthern Illinois University at CarbondaleCarbondaleUSA
  10. 10.Center for Biotechnology, Bioinformatics and Genome ResearchBielefeld UniversityBielefeldGermany
  11. 11.Plants and Microbes Genomics and Genetics LaboratorySouthern Illinois University at CarbondaleCarbondaleUSA

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