title: High Temperature, High Ambient CO₂ Affect the Interactions between Three Positive-Sense RNA Viruses and a Compatible Host Differentially, but not Their Silencing Suppression Efficiencies.
abstract: We compared infection of Nicotiana benthamiana plants by the positive-sense RNA viruses Cucumber mosaic virus (CMV), Potato virus Y (PVY), and by a Potato virus X (PVX) vector, the latter either unaltered or expressing the CMV 2b protein or the PVY HCPro suppressors of silencing, at 25°C vs. 30°C, or at standard (~401 parts per million, ppm) vs. elevated (970 ppm) CO2 levels. We also assessed the activities of their suppressors of silencing under those conditions. We found that at 30°C, accumulation of the CMV isolate and infection symptoms remained comparable to those at 25°C, whereas accumulation of the PVY isolate and those of the three PVX constructs decreased markedly, even when expressing the heterologous suppressors 2b or HCPro, and plants had either very attenuated or no symptoms. Under elevated CO2 plants grew larger, but contained less total protein/unit of leaf area. In contrast to temperature, infection symptoms remained unaltered for the five viruses at elevated CO2 levels, but viral titers in leaf disks as a proportion of the total protein content increased in all cases, markedly for CMV, and less so for PVY and the PVX constructs. Despite these differences, we found that neither high temperature nor elevated CO2 prevented efficient suppression of silencing by their viral suppressors in agropatch assays. Our results suggest that the strength of antiviral silencing at high temperature or CO2 levels, or those of the viral suppressors that counteract it, may not be the main determinants of the observed infection outcomes.
authors: Departamento de Biología Medioambiental, Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain.
authors: Francisco J
authors: FJ
authors: Del Toro
authors: Departamento de Biología Medioambiental, Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain.
authors: Emmanuel
authors: E
authors: Aguilar
authors: Departamento de Biología Medioambiental, Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain.
authors: Francisco J
authors: FJ
authors: Hernández-Walias
authors: Departamento de Biología Medioambiental, Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain.
authors: Francisco
authors: F
authors: Tenllado
authors: National Institute of Horticultural & Herbal Science, Agricultural Research Center for Climate Change, 281, Ayeon-ro, 690-150, Jeju, Jeju Island, Republic of Korea.
authors: Bong-Nam
authors: BN
authors: Chung
authors: Departamento de Biología Medioambiental, Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain.
authors: Tomas
authors: T
authors: Canto
mesh_terms: D015153:Blotting, Western; D002245:Carbon Dioxide / Q000378:metabolism*; D002478:Cells, Cultured; D017799:Cucumovirus / Q000235:genetics / Q000472:pathogenicity*; D016153:Genes, Suppressor; D054884:Host-Pathogen Interactions; D010935:Plant Diseases / Q000235:genetics / Q000821:virology; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism / Q000821:virology; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism / Q000821:virology; D017863:Potexvirus / Q000235:genetics / Q000472:pathogenicity*; D017800:Potyvirus / Q000235:genetics / Q000472:pathogenicity*; D012333:RNA, Messenger / Q000235:genetics; D012367:RNA, Viral / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013696:Temperature; D014026:Nicotiana / Q000235:genetics* / Q000378:metabolism / Q000821:virology
chemical_list: D012333:RNA, Messenger; D012367:RNA, Viral; D002245:Carbon Dioxide