Virus disease in wheat predicted to increase with a changing climate

Area of Science:

• Plant pathology
• Climate change biology
• Agricultural science

Background:

• Atmospheric CO2 levels are rising, with potential impacts on plant-pathogen interactions.
• Barley yellow dwarf virus (BYDV) is a significant pathogen affecting cereal crops like wheat, barley, and oats.
• Understanding how elevated CO2 affects BYDV is crucial for predicting future crop yields.

Purpose of the Study:

• To investigate the effect of ambient (aCO2) and elevated (eCO2) CO2 concentrations on BYDV titre in wheat.
• To determine if increased plant growth under eCO2 explains elevated virus levels.

Main Methods:

• Wheat plants were grown under ambient (400 μmol mol⁻¹) and elevated (650 μmol mol⁻¹) CO2 conditions.
• Plants were either non-infected or infected with BYDV.
• Virus titre was quantified using RT-qPCR in leaf samples.

Main Results:

• BYDV titre in wheat leaves increased by 36.8% under elevated CO2 compared to ambient CO2.
• While elevated CO2 generally enhanced plant growth (height, tiller number, leaf area, biomass), this did not account for the increased BYDV titre.
• Higher virus titre is associated with reduced yield and increased symptom severity, promoting spread.

Conclusions:

• Elevated CO2 levels significantly increase BYDV titre in wheat.
• This interaction poses a potential threat to cereal crop production and global food security.
• This study provides the first quantitative evidence of BYDV titre increase under elevated CO2.