Divergence of host range and biological properties between natural isolate and full-length infectious cDNA clone of the Beet mild yellowing virus 2ITB.

Plant infection by poleroviruses is restricted to phloem tissues, preventing any classical leaf rub inoculation with viral RNA or virions. Efficient virus inoculation to plants is achieved by viruliferous aphids that acquire the virus by feeding on infected plants. The use of promoter-driven infectious cDNA is an alternative means to infect plants and allows reverse genetic studies to be performed.

The benyvirus RNA silencing suppressor is essential for long-distance movement, requires both zinc-finger and NoLS basic residues but not a nucleolar localization for its silencing-suppression activity.

The RNA silencing-suppression properties of Beet necrotic yellow vein virus (BNYVV) and Beet soil-borne mosaic virus (BSBMV) cysteine-rich p14 proteins have been investigated. Suppression of RNA silencing activities were made evident using viral infection of silenced Nicotiana benthamiana 16C, N. benthamiana agroinfiltrated with green fluorescent protein (GFP), and GF-FG hairpin triggers supplemented with viral suppressor of RNA silencing (VSR) constructs or using complementation of a silencing-suppressor-defective BNYVV virus in Chenopodium quinoa.

Plant γH2AX foci are required for proper DNA DSB repair responses and colocalize with E2F factors.

Cellular responses to DNA double-strand breaks (DSBs) are linked in mammals and yeasts to the phosphorylated histones H2AX (γH2AX) repair foci which are multiproteic nuclear complexes responsible for DSB sensing and signalling. However, neither the components of these foci nor their role are yet known in plants. In this paper, we describe the effects of γH2AX deficiency in Arabidopsis thaliana plants challenged with DSBs in terms of genotoxic sensitivity and E2F-mediated transcriptional responses.

Beet necrotic yellow vein virus subgenomic RNA3 is a cleavage product leading to stable non-coding RNA required for long-distance movement.

Beet necrotic yellow vein virus (BNYVV) is a multipartite RNA virus. BNYVV RNA3 does not accumulate in non-host transgenic Arabidopsis thaliana plants when expressed using a 35S promoter. However, a 3'-derivative species has been detected in transgenic plants and in transient expression assays conducted in Nicotiana benthamiana and Beta macrocarpa.

Expression of the Beet necrotic yellow vein virus p25 protein induces hormonal changes and a root branching phenotype in Arabidopsis thaliana.

The RNA-3-encoded p25 protein was previously characterized as one of the major symptom determinants of the Beet necrotic yellow vein virus. Previous analyses reported the influence of the p25 protein in root proliferation phenotype observed in rhizomania disease on infected sugar beets (Beta vulgaris). A transgenic approach was developed, in which the p25 protein was constitutively expressed in Arabidopsis thaliana Columbia (Col-0) ecotype in order to provide new clues as to how the p25 protein might promote alone disease development and symptom expression.

A full-length infectious clone of beet soil-borne virus indicates the dispensability of the RNA-2 for virus survival in planta and symptom expression on Chenopodium quinoa leaves.

For a better understanding of the functionality and pathogenicity of beet soil-borne virus (BSBV), full-length cDNA clones have been constructed for the three genomic RNAs. With the aim of assessing their effectiveness and relative contribution to the virus housekeeping functions, transcripts were inoculated on Chenopodium quinoa and Beta macrocarpa leaves using five genome combinations. Both RNAs-1 (putative replicase) and -3 (putative movement proteins) proved to be essential for virus replication in planta and symptom production on C.