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{{Element
|genbank=[http://www.ncbi.nlm.nih.gov/entrez/viewer.fcgi?db=nucleotide&val=198385718 198385718]
|type=
|genus= Badnavirus
|subfamily= Class 2
|family= Caulimoviridae
|group= LTR retroelements
|description=The plant pararetrovirus ''Citrus yellow mosaic virus'' (CYMV), also called ''Citrus yellow mosaic badnavirus'' (CMBV), is the aetiological agent of "Citrus mosaic disease", a disorder first described in India in 1970s ([[Literature:100657|Dakshinamurti and Reddy 1975]]) and actually widely distributed as a common and severe disease, especially in sweet orange ([[Literature:100653|Ahlawat ''et al.'' 1984]], [[Literature:100654|1996a]],[[Literature:100655|b]]). The virus has been reported from four ''Citrus'' species: Sweet orange (''Citrus sinensis'', [http://www.ncbi.nlm.nih.gov/nuccore/16416936 AF347695]), Rangpur lime (''C. limonia'', [http://www.ncbi.nlm.nih.gov/nuccore/198385718 EU884191]), Acid lime (''C. aurantifolia'', [http://www.ncbi.nlm.nih.gov/nuccore/182239957 EU489744]) and Pummelo (''C. grandis'', [http://www.ncbi.nlm.nih.gov/nuccore/182239990 EU489745]) ([[Literature:100651|Huang and Hurtung 2001]]; [[Literature:86820|Borah ''et al.'' 2009]]). The sequence corresponding to the Rangpur lime CYMV-isolate is that used as reference sequence in our analyses. CYMV is a member of ''Caulimoviridae'' family genus ''Badnavirus'' (''International Committee on the Taxonomy of Viruses'' -ICTV- [[Literature:100589|Fauquet ''et al''. 2005]]) and according to [[Literature:100596|Llorens ''et al''. 2009]] is located within Class 2 of the [[Caulimoviridae|''Caulimoviridae'']] family.

CYMV has a circular double-stranded DNA genome of about 7.5 Kb in size contained in bacilliform-shaped particles of approximately 30x130 nm. It encodes six-seven Open Reading Frames (ORFs) arranged in only one sense and containing the domains highly conserved among all plant pararetroviruses ([[Literature:100651|Huang and Hurtung 2001]]; [[Literature:86820|Borah ''et al.'' 2009]]).
The putative ORF I protein shows sequence similarity to the virion associated proteins (VAPs) encoded by the corresponding ''Caulimoviridae''-ORFs I. ORF II potentially encodes a protein of 15.5 kDa in which have been identified two conserved domains (KQNN and KDPY) homologous to those of the ''Cacao swollen shoot virus'' (CSSV)-ORF II product that seems to possess a DNA-binding property ([[Literature:86820|Borah ''et al.'' 2009]]; [[Literature:100640|Jacquot ''et al.'' 1996]]). In contrast to other isolates, CYMV from Rangpur lime (a species used as rootstock in citrus propagation) is the only one containing seven ORFs because its ORF III is split into two parts (ORF IIIa and ORF IIIb) due to the presence of three stop codons downstream the movement protein region (MOV). In addition to the two cysteine-rich tracts "C-X-C-X2-C-X4-H-X4-C" and "C-X2-C-X11-C-X2-C-X4-C-X2-C" associated to the gag-like region- only observed in Badna- and Tungroviruses and similar to those identified in the nucleocapsid domains of LTR retroelements ([[Literature:100605|Hull 1996]]; [[Literature:8054|Bouhida ''et al.'' 1993]]; [[Literature:100596|Llorens ''et al''. 2009]])- ORF III also contains domains homologous to those of the aspartic protease (PR), the reverse transcriptase (RT) and RNase H (RH) of all other known ''Badnavirus'' species ([[Literature:86820|Borah ''et al.'' 2009]]).
Other small additional ORFs displayed by CYMV genome potentially encode for proteins with a molecular weight of 17.4 kDa (ORF IV), 10.7 kDa (ORF V) and 17.5 kDa (ORF VI). Additional ORFs resembling to CYMV-ORF IV and similarly located within their respective ORF III have also been identified in the genome of other badnaviruses ([[Literature:97967|Su ''et al.'' 2007]]; [[Literature:100643|Yang ''et al.'' 2003]]). The CYMV-ORF V product has limited similarity to those of ORFs IV and V of ''Cassava vein mosaic virus'' (CsVMV), as well as to the ''Soybean chlorotic mottle-like virus'' (SbCMV)-ORF VIII, while the predicted product of ORF VI shows some homologies with the putative product of CSSV-ORF Y ([[Literature:100651|Huang and Hurtung 2001]]). Although these proteins show no significant similarities to those in the databases, conservation of these additional ORFs among the four CYMV isolates would suggest they are functional and are likely expressed ([[Literature:86820|Borah ''et al.'' 2009]]).

CYMV is transmitted by grafting, by its natural vector ''Planococcus citri'' as well as by Agroinoculation with ''Agrobacterium tumefaciens'' transformants ([[Literature:100651|Huang and Hurtung 2001]]; [[Literature:100652|Huang and Hurtung 2008]]). The infected plants show the characteristic "Citrus mosaic disease" symptomatology consisting in yellow mosaic of the leaves and yellow flecking along the veins ([[Literature:100654|Ahlawat ''et al.'' 1996a]]). The affected trees suffer significant severe losses in production and in fruit quality ([[Literature:100654|Ahlawat ''et al.'' 1996a]]).
|structure=CYMV.png
|structure_legend=(VAP=ORF I; MOV=ORF IIIa; COAT(''Gag'')+POL=ORF IIIb; solid line=untranslated region)
|host=Rangpur lime
|hostpic=Rangpur_lime.jpg
|literature=
|picowner=[http://www.ivia.es/ Courtesy of Dr. Pedro Moreno, IVIA, Spain]
}}
[[Category:Element]]

Element:CYMV - Revision history

imported>Gydbwiki at 19:02, 12 March 2010