Molecular Characterization of a Novel Rubodvirus Infecting Raspberries.

A novel negative-sense single-stranded RNA virus showing genetic similarity to viruses of the genus Rubodvirus has been found in raspberry plants in the Czech Republic and has tentatively been named raspberry rubodvirus 1 (RaRV1). Phylogenetic analysis confirmed its clustering within the group, albeit distantly related to other members. A screening of 679 plant and 168 arthropod samples from the Czech Republic and Norway revealed RaRV1 in 10 raspberry shrubs, one batch of Aphis idaei, and one individual of Orius minutus. Furthermore, a distinct isolate of this virus was found, sharing 95% amino acid identity in both the full nucleoprotein and partial sequence of the RNA-dependent RNA polymerase gene sequences, meeting the species demarcation criteria. This discovery marks the first reported instance of a rubodvirus infecting raspberry plants. Although transmission experiments under experimental conditions were unsuccessful, positive detection of the virus in some insects suggests their potential role as vectors for the virus.

Zinc priming enhances Capsicum annuum immunity against infection by Botrytis cinerea- From the whole plant to the molecular level.

Micronutrient manipulation can enhance crop resilience against pathogens, but the mechanisms are mostly unknown. We tested whether priming Capsicum annuum plants with zinc (5 µM Zn) or manganese (3 µM Mn) for six weeks increases their immunity against the generalist necrotroph Botrytis cinerea compared to deficient (0.1 µM Zn, 0.02 µM Mn) and control conditions (1 µM Zn, 0.6 µM Mn). Zinc priming reduced the pathogen biomass and lesion area and preserved CO2 assimilation and stomatal conductance. Zinc mobilization at the infection site, visualized by micro-X-ray fluorescence, was accompanied by increased Zn protein binding obtained by size exclusion HPLC-ICP/MS. A common metabolic response to fungal infection in Zn- and Mn-primed plants was an accumulation of corchorifatty acid F, a signaling compound, and the antifungal compound acetophenone. In vitro tests showed that the binding of Zn2+ increased, while Mn2+ binding decreased acetophenone toxicity against B. cinerea at concentrations far below the toxicity thresholds of both metals in unbound (aquo complex) form. The metal-specific response to fungal infection included the accumulation of phenolics and amino acids (Mn), and the ligand isocitrate (Zn). The results highlight the importance of Zn for pepper immunity through direct involvement in immunity-related proteins and low molecular weight Zn-complexes, while Mn priming was inefficient.

Molecular Characterization of a Novel Enamovirus Infecting Raspberry.

Raspberry plants, valued for their fruits, are vulnerable to a range of viruses that adversely affect their yield and quality. Utilizing high-throughput sequencing (HTS), we identified a novel virus, tentatively named raspberry enamovirus 1 (RaEV1), in three distinct raspberry plants. This study provides a comprehensive characterization of RaEV1, focusing on its genomic structure, phylogeny, and possible transmission routes. Analysis of nearly complete genomes from 14 RaEV1 isolates highlighted regions of variance, particularly marked by indel events. The evidence from phylogenetic and sequence analyses supports the classification of RaEV1 as a distinct species within the Enamovirus genus. Among the 289 plant and 168 invertebrate samples analyzed, RaEV1 was detected in 10.4% and 0.4%, respectively. Most detections occurred in plants that were also infected with other common raspberry viruses. The virus was present in both commercial and wild raspberries, indicating the potential of wild plants to act as viral reservoirs. Experiments involving aphids as potential vectors demonstrated their ability to acquire RaEV1 but not to successfully transmit it to plants.