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Plant Viruses Threaten Crops as Climate Warms

An aphid is tethered by a gold wire

An aphid is tethered by a gold wire to a penetration electrode to measure feeding behaviour and virus transmission.

By Piotr Trebicki

Climate change will exacerbate the spread of a virus that reduces the yield of infected wheat by 70%.

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Barley yellow dwarf virus is an important pathogen that reduces the yield and grain quality of important food crops such as wheat, barley, oats and corn. We have found that the virus thrives when wheat is grown in the laboratory at higher carbon dioxide (CO2) levels, resulting in greater plant damage. Our findings suggest that as CO2 concentrations rise to levels predicted by climate change modellers, food crop plants such as wheat can be badly affected.

Barley yellow dwarf virus is spread by aphids, which acquire it from the sap of an infected plant. As the aphids feed on other plants, they transmit the virus through their saliva. At least 25 species of aphids can successfully transmit this virus between plants, but the major vector is the bird cherry-oat aphid (Rhopalosiphum padi), which is found across Australia and other parts of the world.

A high concentration of the virus in plants causes earlier and more pronounced symptoms in susceptible varieties. As insects are attracted to infected plants by sensing changes in plant colour and odour, this can increase the probability that the virus will spread.