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

Theor Appl Genet. 2005 Oct;111(6):994-1012. doi: 10.1007/s00122-005-2011-y. Epub 2005 Aug 3.


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 Ca(2+)-ATPase, a cyclin D-1, an unknown protein, and a pentatricopeptide repeat (PPR13) gene family member. An approximately 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 Ca(2+)-ATPase. In contrast, 19 sequence polymorphisms were located in an approximately 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 approximately 275-kb gene-poor region with little gene conservation and an adjacent, approximately 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.

Publication types

  • Comparative Study
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Base Sequence
  • Chromosomes, Artificial, Bacterial
  • DNA Primers
  • Evolution, Molecular*
  • Fertility / genetics
  • Gene Components
  • Genes, Plant / genetics*
  • Molecular Sequence Data
  • Oryza / genetics*
  • Phenotype*
  • Physical Chromosome Mapping*
  • Polymorphism, Genetic*
  • Repetitive Sequences, Nucleic Acid / genetics
  • Sequence Analysis, DNA
  • Sorghum / genetics*


  • DNA Primers