Molecular Characterization of Begomoviruses and DNA Satellites Associated With Okra Leaf Curl Disease in Cameroon

Virus Res. 2013 Jun;174(1-2):116-25. doi: 10.1016/j.virusres.2013.03.010. Epub 2013 Mar 25.

Abstract

Okra leaf curl disease (OLCD) is the most important viral disease of okra in West Africa. In this study, a complex of begomoviruses and associated DNA satellites were identified in symptomatic okra plants from southwestern Cameroon. Sequence analyses showed that two of the plants (Lik1 and Njo5) were infected with a begomovirus being a recombinant of cotton leaf curl Gezira virus (CLCuGeV) and okra yellow crinkle virus (OYCrV). The recombinant genome shared highest nucleotide identity with isolates of CLCuGeV at 87.8% and is therefore considered to be member of a new begomovirus species, Okra leaf curl Cameroon virus (OLCuCMV). One plant (Mue5) was infected by a begomovirus with 95.8% nucleotide identy to CLCuGeV, while in the plants Lik1, Mue1 and Njo5, a begomovirus was identified showing highest nucleotide identity at 93.7% with OYCrV. The nucleotide comparisons and phylogenetic analyses suggest that these isolates represent new Cameroonian strains of CLCuGeV and OYCrV (CLCuGeV-CM and OYCrV-CM). Mixed infection of OLCuCMV and OYCrV-CM was found in two of the plants. A betasatellite and two divergent alphasatellites were also associated with the begomoviruses. The betasatellite was identified as cotton leaf curl Gezira betasatellite (CLCuGeB) with the highest nucleotide identity at 93.3% to other African isolates of CLCuGeB. The alphasatellites, herein named Alpha-1 and Alpha-2, shared 97.3% and 95.2% identity, respectively, with cotton leaf curl Gezira alphasatellite (CLCuGeA) and okra leaf curl Burkina Faso alphasatellite (OLCuBFA). These collective results emphasize the extent of diversity among okra-infecting begomovirus-satellite complexes in western Africa.

Publication types

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

MeSH terms

  • Abelmoschus / virology*
  • Begomovirus / genetics*
  • Begomovirus / isolation & purification*
  • Cameroon
  • Cluster Analysis
  • DNA, Satellite / genetics*
  • DNA, Satellite / isolation & purification*
  • DNA, Viral / chemistry
  • DNA, Viral / genetics
  • Genetic Variation
  • Molecular Sequence Data
  • Phylogeny
  • Plant Diseases / virology*
  • Recombination, Genetic
  • Sequence Analysis, DNA
  • Sequence Homology, Nucleic Acid

Substances

  • DNA, Satellite
  • DNA, Viral

Associated data

  • GENBANK/HE793424
  • GENBANK/HE793425
  • GENBANK/HE793426
  • GENBANK/HE793427
  • GENBANK/HE793428
  • GENBANK/HE793429