Bell pepper endornavirus: molecular and biological properties, and occurrence in the genus Capsicum

Abstract

Bell peppers (Capsicum annuum) harbour a large dsRNA virus. The linear genome (14.7 kbp) of two isolates from Japanese and USA bell pepper cultivars were completely sequenced and compared. They shared extensive sequence identity and contained a single, long ORF encoding a 4815 aa protein. This polyprotein contained conserved motifs of putative viral methyltransferase (MTR), helicase 1 (Hel-1), UDP-glycosyltransferase and RNA-dependent RNA polymerase. This unique arrangement of conserved domains has not been reported in any of the known endornaviruses. Hence this virus, for which the name Bell pepper endornavirus (BPEV) is proposed, is a distinct species in the genus Endornavirus (family Endornaviridae). The BPEVencoded polyprotein contains a cysteine-rich region between the MTR and Hel-1 domains, with conserved CXCC motifs shared among several endornaviruses, suggesting an additional functional domain. In agreement with general endornavirus features, BPEV contains a nick in the positive-strand RNA molecule. The virus was detected in all bell pepper cultivars tested and transmitted through seed but not by graft inoculations. Analysis of dsRNA patterns and RT-PCR using degenerate primers revealed putative variants of BPEV, or closely related species, infecting other C. annuum genotypes and three other Capsicum species (C. baccatum, C. chinense and C. frutescens).

Evidence for additive effects of virus infection and water availability on phytohormone induction in a staple crop

“…Virus infection can also impart advantages to infected hosts. For example, genetic stock of certain crop species has been inadvertently selected by breeders for infection with vertically transmitted viruses, presumably because of yield advantages imparted by infection (e.g., Capsicum annuum L., Okada et al, 2011;Roossinck, 2012a). In beets (Beta vulgaris L.), infection with Cucumber mosaic virus (CMV) enhances plant thermal and water-stress tolerance (Xu et al, 2008).…”

Extracción y purificación de dsRNAs largos de plantas infectadas con virus y hongos; aplicación en la detección e identificación de virus

“…En las Figuras 2 y 3 se muestran perfiles de dsRNA de diferentes fitovirus resueltos en geles de poliacrilamida y agarosa. En el caso de los micovirus, los perfiles electroforéticos de dsRNA no se han evaluado extensamente como una herramienta para Demler and Zoeten, 1989;Dodds, 1982;Falk et al, 1979;Okada et al, 2011;Valverde et al, 1995;Ward et al, 2009) and fungi (Azzam and Gonsalves, 1999;Deng and Boland, 2004;Kousik et al, 1994;Feldman et al 2012;Pecina et al, 2000;Shamoun et al, 2008). In plants, mixed viral infections often go undetected and can result in inadequate disease diagnoses.…”

“…Moreover, gel electrophoretic profiles of viral dsRNA have been used to differentiate strains of Tomato mosaic virus , CMV (Valverde et al, 1990a), and CTV (Dodds et al, 1987). Nevertheless, in plants, members of the viral Torre, et al, 2014;Demler y Zoeten, 1989;Dodds, 1982;Falk et al, 1979;Okada et al, 2011;Valverde y Dodds, 1986;Valverde et al, 1995;Ward et al, 2009) y hongos (Azzam y Gonsalves, 1999;Deng y Boland, 2004;Kousik et al, 1994;Feldman et al 2012;Pecina et al, 2000;Shamoun et al, 2008).…”

“…Viral dsRNAs have been used to clone and sequence plant and fungal RNA viruses (Aboughanem- Sabanadzovic et al, 2016;Antoniw et al, 1986;Bar-Joseph et al, 1983;Enebak et al, 1994;Herrero et al, 2009;Khalifa and Pearson, 2014;Kim et al, 2005;Okada et al 2011;Rott and Jelkmann, 2001;Jelkmann et al, 1989;Valverde and Sabanadzovic, 2009;Zhang and Rowhani, 2000). Virus specific primers have been developed for RT-PCR detection of most plant and fungal viruses reported to date.…”

“…Zhang and Rowhani (2000) developed a rapid cDNA cloning method from dsRNA templates to partially characterized grape viruses. Random cDNA clones from CTV nem- Sabanadzovic et al, 2016;Antoniw et al, 1986;Bar-Joseph et al, 1983;Enebak et al, 1994;Herrero et al, 2009;Khalifa y Pearson, 2014;Kim et al, 2005;Okada et al 2011;Rott y Jelkmann, 2001;Jelkmann et al, 1989;Valverde y Sabanadzovic, 2009;Valverde y Sabanadzovic;Zhang y Rowhani, 2000). Se han creado iniciadores según el tipo de virus para detectar mediante RT-PCR la mayoría de los fitovirus y los micovirus reportados a la fecha.…”