caa a22 4500 475766997 CHVBK 20180406123608.0 cr unu---uuuuu 170329e20000801xx s 000 0 eng 10.1007/s007050070084 doi (NATIONALLICENCE)springer-10.1007/s007050070084 The open reading frame 5A of foxtail mosaic virus is expressed in vivo and is dispensable for systemic infection [Elektronische Daten] [N. L. Robertson, R. French, T. J. Morris] Summary.:  Infectious transcripts were successfully derived from full-length cDNA clones of foxtail mosaic potexvirus (FoMV). Full-length clones were constructed by RT-PCR whereby 5′ and 3′ genomic segments of 2.7 and 3.4 kb, respectively, were ligated into Bluescript II KS. The in vitro RNA transcripts were infectious to moncotyledonous (barley) and dicotyledonous (Chenopodium amaranticolor) plant species. Individual mutation studies on clones of each of the five major ORFs confirmed predicted gene function for the polymerase, TGB (triple gene block), and coat protein (CP) genes. Protoplast studies on expression of a unique open reading frame, ORF 5A, which initiates 143 nts upstream of the CP before it "reads through” the CP, revealed that the 5A protein was produced in vivo. Mutation analysis of the 5A ORF indicated, however, that it was not required for either replication or for productive infection of plants. However, the nucleic acid sequences encoding the extended CP segment were shown to be important for CP expression. Additional mutations in 5A had no effect on FoMV replication in protoplasts but rendered the virus noninfectious to plants. A correlation with diminished CP production from both mutant clones implies that synthesis of subgenomic CP mRNA was compromised, and this limited systemic infection. Springer-Verlag/Wien, 2000 Robertson N. L. United States Department of Agriculture-Agricultural Research Service, Arctic Plant Germplasm Repository, Palmer, Alaska, US aut French R. United States Department of Agriculture-Agricultural Research Service, Department of Plant Pathology, University of Nebraska, Nebraska, U.S.A., US aut Morris T. J. School of Biological Sciences, University of Nebraska, Lincoln, Nebraska, U.S.A., US aut https://doi.org/10.1007/s007050070084 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s007050070084 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Robertson N. L. United States Department of Agriculture-Agricultural Research Service, Arctic Plant Germplasm Repository, Palmer, Alaska, US aut NATIONALLICENCE 700 1- French R. United States Department of Agriculture-Agricultural Research Service, Department of Plant Pathology, University of Nebraska, Nebraska, U.S.A., US aut NATIONALLICENCE 700 1- Morris T. J. School of Biological Sciences, University of Nebraska, Lincoln, Nebraska, U.S.A., US aut Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer