Arabidopsis thaliana as a model host for Brevipalpus mite-transmitted viruses

ABSTRACT: Brevipalpus-transmitted viruses (BTV) are a taxonomically diverse group of plant viruses which severely affect a number of major crops. Members of the group can be sub-classified into cytoplasmic (BTV-C) or nuclear type (BTV-N) according to the accumulation sites of virions in the infected plant cells. Both types of BTV produce only local infections near the point of inoculation by viruliferous mites. Features of BTV-plant interactions such as the failure of systemic spread in their natural hosts are poorly understood. In this study we evaluated Arabidopsis thaliana, a model plant commonly used for the study of plant-virus interactions, as an alternative host for BTV. Infection of Arabidopsis with the BTV-N Coffee ringspot virus and Clerodendrum chlorotic spot virus, and the BTV-C Solanum violaefolium ringspot virus, were mediated by viruliferous Brevipalpus mites collected in the wild. Upon infestation, local lesions appeared in 7 to 10 days on leaves of, at least, 80 % of the assayed plants. Presence of viral particles and characteristic cytopathic effects were detected by transmission electron microscopy (TEM) and the viral identities confirmed by specific reverse-transcriptase polymerase chain reaction (RT-PCR) and further amplicon sequencing. The high infection rate and reproducibility of symptoms of the three different viruses assayed validate A. thaliana as a feasible alternative experimental host for BTV

An annotated list of ornamentals naturally found infected by Brevipalpus mite-transmitted viruses

The first cases of ornamental plants found infected by Brevipalpus transmitted viruses (BTV) were described in the 1990's from the region of Piracicaba, State of São Paulo, Brazil; subsequent cases were from other regions in the country and other American countries. Currently, 37 ornamental plant species (for the sake of simplicity, orchids being considered as a single species), belonging to 18 families of dicotyledons, have been reported hosting BTV. Because of the non systemic type of infection of these viruses, the localized diseases they cause are unimportant usually, but they have the potential to cause economic losses if severe outbreaks of Brevipalpus mite populations occur. Some ornamentals may serve as reservoirs to BTV known to cause serious damage to food crops as Citrus leprosis virus- cytoplasmic type (CiLV-C), passion fruit green spot virus (PFGSV) and Coffee ringspot virus (CoRSV).Os primeiros casos de plantas ornamentais encontradas naturalmente infetadas por vírus transmitidos por Brevipalpus (Acari: Tenuipalpidae) (VTB) foram registrados nos anos 1990 na região de Piracicaba, Estado de São Paulo, e ocorrências subseqüentes foram observadas em várias outras regiões do país e de outros países das Américas. Atualmente acham-se relatadas 37 espécies de ornamentais (para efeito de simplificação, orquídeas foram consideradas como única espécie) pertencentes a 18 famílias botânicas. Pelo fato de causarem apenas infecções localizadas, geralmente nas folhas, VTB em ornamentais não causam preocupações aos produtores, mas potencialmente podem causar perdas econômicas se ocorrerem explosões populacionais do ácaro vetor. Plantas ornamentais podem servir de reservatório de VTB de importância econômica como os vírus da leprose dos citros-tipo citoplasmático (CiLV-C), da mancha verde do maracujá (PFGSV) e da mancha anular do cafeeiro (CoRSV)