Jan F. Kreuze*
Alphaflexiviridae Study Group Chair
International Potato Center (CIP)
Apartado 1558
Lima 12
Peru
E-mail: j.kreuze@cgiar.org
Anna Maria Vaira
Institute for Sustainable Plant Protection, CNR
73 Strada delle Cacce
10135 Torino
Italy
E-mail: annamaria.vaira@ipsp.cnr.it
Potexviruses have relatively short virions (<700 nm) and their genomes have only five ORFs. Potexviruses infect herbaceous hosts and have no known vectors.
Allexiviruses are distinguished by mite transmission and by the presence of a large conserved ORF4 or 5 after the position where the third, and smallest, of the triple gene block (TGB) proteins, TGB3, is found in the other plant-infecting members of the family. Whereas the start codon is missing for the TGB3 ORF in most (but not all) genus members, the coding capacity is conserved and the ORF may be translated through alternative mechanisms.
Jan F. Kreuze, Anna Maria Vaira, Wulf Menzel, Thierry Candresse, Sergei K. Zavriev, John Hammond and Ki Hyun Ryu
Rhizouliviruses have a mono-segmented genome, infect fungi, and are phylogenetically distinct from other botourmiaviruses.
No true virions are associated with rhizouliviruses since their genomes have no capsid protein gene.
