Plant viruses grouped within this family have remarkable properties, prominent among which is their genomic size: Citrus tristeza virus (CTV) has the largest (19.3 kb) genome reported for a plant monopartite single-stranded RNA (+) virus. Virions are filamentous and typically flexuous particles, approximately 12 nm in diameter and 650 to 2000 nm in length, with a unique bipolar (“rattlesnake”) morphology: the major coat protein (CP) encapsidates most of the genomic RNA, with a minor CP (CPm) coating a small 5’-terminal fragment (virion tail) and other viral-encoded proteins being also incorporated to this tail. The genome is monopartite (genus Closterovirus, type member Beet yellows virus, and genus Ampelovirus, type member Grapevine leafroll-associated virus 3) or bipartite (genus Crinivirus, type member Lettuce infectious yellows virus, with at least one example of tripartite genome). The genomic RNA (or RNA1 in criniviruses) directs translation of the two 5’-proximal ORFs (via a peculiar ribosomal frameshift mechanism and proteolytic processing) that encode replication-related components, with the 3’-proximal ORFs encoding proteins expressed from 3’-coterminal subgenomic RNAs. A genomic signature of members of the family Closteroviridae is the presence of a five-gene block of proteins involved in virion assembly and movement that, in addition to the CP and CPm, includes a small transmembrane protein, a homologue of the HSP70 class of heat-shock proteins and a diverged CP. Members of this family encode suppressors of RNA silencing differing in number (up to three in CTV), and in mode of action: intracellular, intercellular, or both. In this same context Sweet potato chlorotic stunt virus codes for a singular suppressor: an RNase III that catalyzes cleavage of the small interfering RNAs mediating RNA silencing. Host range is usually narrow and, in order to expand it, some member(s) of the family, illustrated by the case of CTV, have evolved by acquiring multiple non-conserved genes. Virion accumulation is restricted to the phloem, with aphids, mealybugs and whiteflies (depending on the genus) operating as natural vectors. Disease symptoms may be expressed in leaves, fruits and trunk of the woody hosts. Natural Plant viruses grouped within this family have remarkable properties, prominent among which is their genomic size: Citrus tristeza virus (CTV) has the largest (19.3 kb) genome reported for a plant monopartite single-stranded RNA (+) virus. Virions are filamentous and typically flexuous particles, approximately 12 nm in diameter and 650 to 2000 nm in length, with a unique bipolar (“rattlesnake”) morphology: the major coat protein (CP) encapsidates most of the genomic RNA, with a minor CP (CPm) coating a small 5’-terminal fragment (virion tail) and other viral-encoded proteins being also incorporated to this tail. The genome is monopartite (genus Closterovirus, type member Beet yellows virus, and genus Ampelovirus, type member Grapevine leafroll-associated virus 3) or bipartite (genus Crinivirus, type member Lettuce infectious yellows virus, with at least one example of tripartite genome). The genomic RNA (or RNA1 in criniviruses) directs translation of the two 5’-proximal ORFs (via a peculiar ribosomal frameshift mechanism and proteolytic processing) that encode replication-related components, with the 3’-proximal ORFs encoding proteins expressed from 3’-coterminal subgenomic RNAs. A genomic signature of members of the family Closteroviridae is the presence of a five-gene block of proteins involved in virion assembly and movement that, in addition to the CP and CPm, includes a small transmembrane protein, a homologue of the HSP70 class of heat-shock proteins and a diverged CP. Members of this family encode suppressors of RNA silencing differing in number (up to three in CTV), and in mode of action: intracellular, intercellular, or both. In this same context Sweet potato chlorotic stunt virus codes for a singular suppresso.
This book provides the latest valuable overview of the plant virus and virus-like diseases in tropical countries on aspects like introduction about plant viruses, their classification; transmission and diagnostic techniques; the well ...
This book provides methods and clear protocols for the various technologies available to detect, characterize, and study Citrus tristeza virus (CTV), a member of the genus Closterovirus, family Closteroviridae.
This comprehensive Encyclopedic Reference systematically integrates the state-of-the-art knowledge on all virus genera in the standardized format of lists, tables and figures. Each chapter provides highly structured and condensed information...
O'Reilly , E.K. , Tang , N. , Ahlquist , P. and Kao , C.C. ( 1995 ) . Biochemical and genetic analysis of the ... Reilly , E.K. , Wang , Z. , French , R. and Kao , C.C. ( 1998 ) . Interactions between the structural domains of the RNA ...
The Second Edition has been thoroughly updated with approximately 40 new articles. This edition includes more illustrations and color plates in each volume.
The book builds upon the last handbook (written over twenty years ago) on the part of diagnostics and extensively expands its scope by inclusion of molecular biology aspects of select viruses that are widespread and economically most ...
... Closteroviridae Crinivirus infectious yellows virus 15 Cucurbit Closteroviridae Crinivirus chlorotic yellow virus 16 Cucurbit yellow Closteroviridae Crinivirus stunting disorder virus 17 Cucumber Closteroviridae Crinivirus yellows virus ...
The Epidemiology of Barley Yellow Dwarf in Europe. In: World Perspectives on Barley Yellow Dwarf. P.A. Burnett (ed). CIMMYT, Mexico Plumb, R.T. 1992. Barley yellow dwarf. In: Plant Disease of International Importance, Vol. 1.
... Closteroviridae, which might increase the virus diversity in a single host plant (Iglesias et al., 2008; Roy and Brlansky, 2009; Rubio et al., 2013). and HEL, necessary for viral replication, the ORF1a of some AcV1 variants harbors a ...
This fifth edition of the classic textbook in plant pathology outlines how to recognize, treat, and prevent plant diseases.