Media release

From: The Royal Society

Elevated atmospheric CO2 changes defence allocation in wheat but herbivore resistance persists

Silicon wheat valley – Higher CO2 levels under future climate conditions, may cause wheat to shift its pest defence strategy. When researchers grew wheat under elevated levels of CO2, they found growth and carbon-based defences increase, while silicon-based defences reduced by 19%. Applying silicon fertilisers may be beneficial for maintaining herbivore resistance in crops under future elevated levels of CO2, the authors say.

Just three grass crops (wheat, maize and rice) provide 42% of human calories. Grasses take up and accumulate silicon in their tissues to resist adverse environmental conditions, including herbivore attack. All plants must, however, allocate their limited resources to growth, reproduction and anti-herbivore defences in an optimal manner depending on environmental conditions. We show that under elevated atmospheric CO2, wheat switches from silicon-based defences to carbon-based defences, but that anti-herbivore silicon defences persist even at diminished levels. Our study suggests that managing silicon availability in agricultural soils could be important for maintaining wheat resistance to pests in future climates.