New Disease Reports (2006) 12, 38.

First report of Tobacco leaf curl Zimbabwe virus affecting tobacco in the Comoros Archipelago

J.M. Lett 1*, F. Lefeuvre 1, F. Naze 1, H. Delatte 1, Y. Mohamed-Ali 2 and B. Reynaud 1

*lett@cirad.fr

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Accepted: 06 Jan 2006

In March 2004, within the Regional Program of Plant Protection, an inventory of plant pathogens was organised in the Comoros Archipelago, located in the northern part of the Mozambique Channel. Symptoms of leaf curling and yellowing (Fig. 1) were observed on tobacco plants in the Grande-Comore Island; the most northern Island of the Archipelago and the closest to the African continent.

Leaf samples from tobacco plants presenting the most severe symptoms, were collected from three different locations: Foumboudzivouni (eastern region), Foumbouni (southeast region) and Simboussa (southern region). Samples were conserved by dehydration and tested for the presence of begomoviruses using polymerase chain reaction (PCR) assays with two sets of degenerate primers designed to amplify part of the coat protein (CP) gene of the DNA A component. The first primer set used (AV494 and AC1048) amplify the approximately 550bp core region of the CP gene (Wyatt & Brown, 1996). The second primer set used (VD360 and CD1266) amplify an approximately 800bp fragment representing more than 90% of the CP gene (Delatte et al., 2005). PCR products of the expected size were obtained with both sets of primers. No PCR products were obtained with degenerate primers designed for begomovirus DNA B or DNA β. PCR products obtained with primers VD360 and CD1266 from one sample each originating from Foumboudzivouni (EMBL accession no. AM156758), Foumbouni (AM156760) and Simboussa (AM156759) were cloned and sequenced. The three sequences showed 97% nucleotide sequence identity (DNAMAN, Lynnon BioSoft). The most significant sequence alignments (NCBI, BLASTn) were 95 to 96% with Tobacco leaf curl Zimbabwe virus (TbLCZV; AF350330) and 83 to 85% with Chayotte yellow mosaic virus (ChaYMV; AJ223191). The 552bp core CP sequences, which are sometimes used to provide provisional identification of begomoviruses (Brown et al., 2001), showed 95 to 97% nucleotide sequence identity with TbLCZV and 83 to 84% with ChaYMV (Fig. 2).

These results demonstrate the presence of TbLCZV on tobacco in the Grande-Comore Island of the Comoros Archipelago. Previous reports have identified the presence of distinct indigenous begomoviruses on tomato in the south west islands of the Indian Ocean (Delatte et al., 2005), but this is the first report of TbLCZV.

Figure1a+Figure1b+
Figure 1: Severe symptoms of leaf curling and yellowing observed on tobacco plants in the field on the Grande Comore Island of the Comoros Archipelago
Figure 1: Severe symptoms of leaf curling and yellowing observed on tobacco plants in the field on the Grande Comore Island of the Comoros Archipelago
Figure2+
Figure 2: Neighbour joining tree indicating the relationships between the 522 bp core region of the coat protein of three isolates of Tobacco leaf curl Zimbabwe virus (TbLCZV) from the Grande Comore Island and those of representative African and Mediterranean begomovirus sequences. The sequence alignment and the tree construction were conducted using DNAMAN software (Lynnon BioSoft, Quebec, Canada). The tree was rooted on Tobacco leaf curl Japan virus (TbLCJV, AB028604). Numbers associated with the nodes indicate the percentage support for those nodes in 1000 bootstrap replicates. Horizontal distances represent genetic distances, as indicated by the scale bar, whereas vertical distances are arbitrary. Nucleotide sequence database accession numbers of sequences used in this study: Tomato yellow leaf curl virus - Mild[Reunion] (TYLCV-Mld[RE]; AJ865337), TYLCV-Mld (X76319), TYLCV (X15656), Tomato leaf curl Madagascar virus - [Morondava] (ToLCMGV-[Mor], AJ865338), ToLCMGV-[Toliary] (ToLCMGV-[Tol], AJ865339), Tomato leaf curl Mayotte virus - [Dembeni] (ToLCMGV-[Dem], AJ865341), ToLCMGV-[Kahani] (ToLCMGV-[Kah], AJ865340), South African cassava mosaic virus - [M12] (SACMV-[M12], AJ422132), East African cassava mosaic virus - [Tanzania] (EACMV-[TZ], Z83256), African cassava mosaic virus - Uganda Severe (ACMV-UgSvr, AF26806), Tomato curly stunt virus - South Africa (ToCSV-SA, AF261885), Cotton leaf curl Gezira virus - [Sida] (CLCuGV-[Si], AY036007), Tobacco leaf curl Zimbabwe virus - [Simboussa] (TbLCZV-[Sim], AM156759), TbLCZV - [Foumbouni] (TbLCZV-[Fon], AM156760), TbLCZV - [Foumboudzivouni] (TbLCZV-[Fod], AM156758), TbLCZV - [B] (AF077026), TbLCZV - [H] (AF077747), TbLCZV - [M] (AF077748), TbLCZV - [S] (AF077749) and Chayotte yellow mosaic virus (ChaYMV, AJ223191).
Figure 2: Neighbour joining tree indicating the relationships between the 522 bp core region of the coat protein of three isolates of Tobacco leaf curl Zimbabwe virus (TbLCZV) from the Grande Comore Island and those of representative African and Mediterranean begomovirus sequences. The sequence alignment and the tree construction were conducted using DNAMAN software (Lynnon BioSoft, Quebec, Canada). The tree was rooted on Tobacco leaf curl Japan virus (TbLCJV, AB028604). Numbers associated with the nodes indicate the percentage support for those nodes in 1000 bootstrap replicates. Horizontal distances represent genetic distances, as indicated by the scale bar, whereas vertical distances are arbitrary. Nucleotide sequence database accession numbers of sequences used in this study: Tomato yellow leaf curl virus - Mild[Reunion] (TYLCV-Mld[RE]; AJ865337), TYLCV-Mld (X76319), TYLCV (X15656), Tomato leaf curl Madagascar virus - [Morondava] (ToLCMGV-[Mor], AJ865338), ToLCMGV-[Toliary] (ToLCMGV-[Tol], AJ865339), Tomato leaf curl Mayotte virus - [Dembeni] (ToLCMGV-[Dem], AJ865341), ToLCMGV-[Kahani] (ToLCMGV-[Kah], AJ865340), South African cassava mosaic virus - [M12] (SACMV-[M12], AJ422132), East African cassava mosaic virus - [Tanzania] (EACMV-[TZ], Z83256), African cassava mosaic virus - Uganda Severe (ACMV-UgSvr, AF26806), Tomato curly stunt virus - South Africa (ToCSV-SA, AF261885), Cotton leaf curl Gezira virus - [Sida] (CLCuGV-[Si], AY036007), Tobacco leaf curl Zimbabwe virus - [Simboussa] (TbLCZV-[Sim], AM156759), TbLCZV - [Foumbouni] (TbLCZV-[Fon], AM156760), TbLCZV - [Foumboudzivouni] (TbLCZV-[Fod], AM156758), TbLCZV - [B] (AF077026), TbLCZV - [H] (AF077747), TbLCZV - [M] (AF077748), TbLCZV - [S] (AF077749) and Chayotte yellow mosaic virus (ChaYMV, AJ223191).

Acknowledgements

This study was initiated by the Regional Program of Plant Protection and funded by the European Union and the Conseil Rí©gional de La Rí©union.


References

  1. Brown JK, Idris AM, Torres-Jerez I, Banks GK, Wyatt SD, 2001. The core region of the coat protein gene is highly useful for establishing the provisional identification and classification of begomoviruses. Archives of Virology 146, 1581-1598.
  2. Delatte H, Martin DP, Naze F, Goldbach R, Reynaud B, Peterschmitt M, Lett JM, 2005. South West Indian Ocean islands tomato begomovirus populations represent a new major monopartite begomovirus group. Journal of General Virology 86, 1533-1542.
  3. Wyatt SD, Brown JK, 1996. Detection of subgroup III geminivirus isolates in leaf extracts by degenerate primers and polymerase chain reaction. Phytopathology 86, 1288-1293.

This report was formally published in Plant Pathology

©2006 The Authors