Characterisation of the genetic diversity of citrus viroid VII using amplicon sequencing.

Viroids occur in plants as swarms of sequence variants clustered around a dominant variant, leading to adoption of the term 'quasispecies' to describe the viroid population in an individual host. The composition of the quasispecies can potentially change according to the age of the infection, the position of the leaf or branch in the canopy, and the host species. The primary aim of this study was to investigate the quasispecies concept for citrus viroid VII (CVd-VII), a recently discovered member of the family Pospiviroidae.

Molecular characterisation of a novel sadwavirus infecting cattleya orchids in Australia.

The complete genome sequence of a novel sadwavirus infecting cattleya orchids in South East Queensland is described. Isometric virions of c. 27 nm diameter were observed in sap extracts viewed under a transmission electron microscope, and the genome sequence of this virus was determined by high-throughput sequencing.

Endogenous Caulimovirids: Fossils, Zombies, and Living in Plant Genomes.

The is a family of double-stranded DNA viruses that infect plants. The genomes of most vascular plants contain endogenous caulimovirids (ECVs), a class of repetitive DNA elements that is abundant in some plant genomes, resulting from the integration of viral DNA in the chromosomes of germline cells during episodes of infection that have sometimes occurred millions of years ago. In this review, we reflect on 25 years of research on ECVs that has shown that members of the have occupied an unprecedented range of ecological niches over time and shed light on their diversity and macroevolution.

Rational design of a survey protocol for avocado sunblotch viroid in commercial orchards to demonstrate pest freedom.

Avocado sunblotch viroid (ASBVd) is a subcellular pathogen of avocado that reduces yield from a tree, diminishes the appearance of the fruit by causing unsightly scarring and impedes trade because of quarantine conditions that are imposed to prevent spread of the pathogen via seed-borne inoculum. For countries where ASBVd is officially reported, permission to export fruit to another country may only be granted if an orchard can be demonstrated to be a pest free production site. The survey requirements to demonstrate pest freedom are usually defined in export protocols that have been mutually agreed upon by the trading partners.

CAULIFINDER: a pipeline for the automated detection and annotation of caulimovirid endogenous viral elements in plant genomes.

Plant, animal and protist genomes often contain endogenous viral elements (EVEs), which correspond to partial and sometimes entire viral genomes that have been captured in the genome of their host organism through a variety of integration mechanisms. While the number of sequenced eukaryotic genomes is rapidly increasing, the annotation and characterization of EVEs remains largely overlooked. EVEs that derive from members of the family Caulimoviridae are widespread across tracheophyte plants, and sometimes they occur in very high copy numbers.