title: Virus disease in wheat predicted to increase with a changing climate.
abstract: Current atmospheric CO2 levels are about 400 μmol mol(-1) and are predicted to rise to 650 μmol mol(-1) later this century. Although the positive and negative impacts of CO2 on plants are well documented, little is known about interactions with pests and diseases. If disease severity increases under future environmental conditions, then it becomes imperative to understand the impacts of pathogens on crop production in order to minimize crop losses and maximize food production. Barley yellow dwarf virus (BYDV) adversely affects the yield and quality of economically important crops including wheat, barley and oats. It is transmitted by numerous aphid species and causes a serious disease of cereal crops worldwide. This study examined the effects of ambient (aCO2 ; 400 μmol mol(-1) ) and elevated CO2 (eCO2 ; 650 μmol mol(-1) ) on noninfected and BYDV-infected wheat. Using a RT-qPCR technique, we measured virus titre from aCO2 and eCO2 treatments. BYDV titre increased significantly by 36.8% in leaves of wheat grown under eCO2 conditions compared to aCO2 . Plant growth parameters including height, tiller number, leaf area and biomass were generally higher in plants exposed to higher CO2 levels but increased growth did not explain the increase in BYDV titre in these plants. High virus titre in plants has been shown to have a significant negative effect on plant yield and causes earlier and more pronounced symptom expression increasing the probability of virus spread by insects. The combination of these factors could negatively impact food production in Australia and worldwide under future climate conditions. This is the first quantitative evidence that BYDV titre increases in plants grown under elevated CO2 levels.
authors.affiliation: Biosciences Research Division, Department of Economic Development, (DED), 110 Natimuk Rd, Horsham, Vic., 3400, Australia.
authors.forename: Piotr
authors.initials: P
authors.lastname: Trębicki
authors.affiliation: Biosciences Research Division, DED, La Trobe University, 5 Ring Road, Bundoora, Vic., 3083, Australia.
authors.forename: Narelle
authors.initials: N
authors.lastname: Nancarrow
authors.affiliation: Department of Biology, Loyola University Chicago, 1032 West Sheridan Road, Chicago, IL, 60660, USA.
authors.forename: Ellen
authors.initials: E
authors.lastname: Cole
authors.affiliation: Department of Plant, Soil and Entomological Sciences, University of Idaho, 875 Perimeter Drive MS 2339, Moscow, ID, 83844-2339, USA.
authors.forename: Nilsa A
authors.initials: NA
authors.lastname: Bosque-Pérez
authors.affiliation: Biosciences Research Division, DED, La Trobe University, 5 Ring Road, Bundoora, Vic., 3083, Australia.
authors.forename: Fiona E
authors.initials: FE
authors.lastname: Constable
authors.affiliation: Biosciences Research Division, Department of Economic Development, (DED), 110 Natimuk Rd, Horsham, Vic., 3400, Australia.
authors.forename: Angela J
authors.initials: AJ
authors.lastname: Freeman
authors.affiliation: Biosciences Research Division, DED, La Trobe University, 5 Ring Road, Bundoora, Vic., 3083, Australia.
authors.forename: Brendan
authors.initials: B
authors.lastname: Rodoni
authors.affiliation: Biosciences Research Division, DED, La Trobe University, 5 Ring Road, Bundoora, Vic., 3083, Australia.|School of Applied Systems Biology, La Trobe University, Bundoora, Vic., 3083, Australia.
authors.forename: Alan L
authors.initials: AL
authors.lastname: Yen
authors.affiliation: Plant Biosecurity Cooperative Research Centre, LPO Box 5012, Bruce, ACT, Australia.
authors.forename: Jo E
authors.initials: JE
authors.lastname: Luck
authors.affiliation: Agriculture Research Division, DED, 110 Natimuk Rd, Horsham, Vic., 3400, Australia.
authors.forename: Glenn J
authors.initials: GJ
authors.lastname: Fitzgerald
mesh_terms: D001315:Australia; D002245:Carbon Dioxide / Q000378:metabolism*; D057231:Climate Change; D018556:Crops, Agricultural / Q000821:virology*; D054884:Host-Pathogen Interactions; D017793:Luteovirus / Q000502:physiology*; D010935:Plant Diseases / Q000821:virology*; D016133:Polymerase Chain Reaction; D014908:Triticum / Q000821:virology*
chemical_list: D002245:Carbon Dioxide
keywords: BYDV-PAV; Barley yellow dwarf virus; CO
  2; RT-qPCR; carbon dioxide; climate change; disease; pathogen; plant