The Torradovirus‐specific RNA2‐ORF1 protein is necessary for plant systemic infection

• DOI: 10.1111/mpp.12615
• Publication Date: 2017-09-21T07:22:33Z
• Authors: INMACULADA Ferriol; MARTA Vallino; MARINA Ciuffo; JARED C. Nigg; ERIKA J. Zamora‐M...; BRYCE W. Falk; Massimo Turina
• Keywords: Movement protein

Tomato apex necrosis virus (ToANV, species marchitez virus, genus Torradovirus, family Secoviridae) causes a severe tomato disease in Mexico. One distinctive feature of torradoviruses compared with other members the Secoviridae is presence an additional open reading frame (ORF) genomic RNA2 (denominated RNA2-ORF1), located upstream ORF2. RNA2-ORF2 encodes polyprotein that processed into putative movement protein and three capsid proteins (CPs). The RNA2-ORF1 has homologues only amongst and, so far, no function been associated it. We used recombinant mutant ToANV clones to investigate role various aspects infection cycle. lack functional resulted inability systemically infect Nicotiana benthamiana plants, but both positive- negative-strand RNA1 accumulated locally agroinfiltrated areas N. indicating mutants were replication competent. Furthermore, deletion was competent for virion formation cell-to-cell cells immediately surrounding initial site. However, immunological detection CPs showed this not detected sieve elements even if parenchymatic positive, suggesting processes occurring prior phloem uploading, including efficient spread inoculated leaves.