Theoretical and Applied Genetics

, Volume 111, Issue 6, pp 994–1012

Fertility restorer locus Rf1 of sorghum (Sorghum bicolor L.) encodes a pentatricopeptide repeat protein not present in the colinear region of rice chromosome 12

  • R. R. Klein
  • P. E. Klein
  • J. E. Mullet
  • P. Minx
  • W. L. Rooney
  • K. F. Schertz
Original Paper

DOI: 10.1007/s00122-005-2011-y

Cite this article as:
Klein, R.R., Klein, P.E., Mullet, J.E. et al. Theor Appl Genet (2005) 111: 994. doi:10.1007/s00122-005-2011-y
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Abstract

With an aim to clone the sorghum fertility restorer gene Rf1, a high-resolution genetic and physical map of the locus was constructed. The Rf1 locus was resolved to a 32-kb region spanning four open reading frames: a plasma membrane Ca2+-ATPase, a cyclin D-1, an unknown protein, and a pentatricopeptide repeat (PPR13) gene family member. An ~19-kb region spanning the cyclin D-1 and unknown protein genes was completely conserved between sterile and fertile plants as was the sequence spanning the coding region of the Ca2+-ATPase. In contrast, 19 sequence polymorphisms were located in an ~7-kb region spanning PPR13, and all markers cosegregated with the fertility restoration phenotype. PPR13 was predicted to encode a mitochondrial-targeted protein containing a single exon with 14 PPR repeats, and the protein is classified as an E-type PPR subfamily member. To permit sequence-based comparison of the sorghum and rice genomes in the Rf1 region, 0.53 Mb of sorghum chromosome 8 was sequenced and compared to the colinear region of rice chromosome 12. Genome comparison revealed a mosaic pattern of colinearity with an ~275-kb gene-poor region with little gene conservation and an adjacent, ~245-kb gene-rice region that is more highly conserved between rice and sorghum. Despite being located in a region of high gene conservation, sorghum PPR13 was not located in a colinear position on rice chromosome 12. The present results suggest that sorghum PPR13 represents a potential candidate for the sorghum Rf1 gene, and its presence in the sorghum genome indicates a single gene transposition event subsequent to the divergence of rice and sorghum ancestors.

Keywords

SorghumFertility restorerMap-based cloningPentatricopeptide repeat proteinMicrosynteny

Copyright information

© Springer-Verlag 2005

Authors and Affiliations

  • R. R. Klein
    • 1
  • P. E. Klein
    • 2
  • J. E. Mullet
    • 3
  • P. Minx
    • 4
  • W. L. Rooney
    • 5
  • K. F. Schertz
    • 1
  1. 1.Southern Plains Agricultural Research CenterUSDA–ARSCollege StationUSA
  2. 2.Department of Horticulture and Institute for Plant Genomics and BiotechnologyTexas A&M UniversityCollege StationUSA
  3. 3.Department of Biochemistry and Biophysics and Institute for Plant Genomics and BiotechnologyTexas A&M UniversityCollege StationUSA
  4. 4.Washington University Genome Sequencing CenterWashington University School of MedicineSt. LouisUSA
  5. 5.Department of Soil and Crop SciencesTexas A&M UniversityCollege StationUSA