Scientists Engineer Plants Resistant To Heatwaves As Crops Hit By Climate Crisis

Modern agricultural methods mean around 40 per cent of all crops are currently lost to pests and diseases. But as the climate crisis worsens, the outlook is set to become even more grim. When heatwaves strike, crops can be decimated, hitting human food supplies, as well as the plants grown to feed livestock and for biofuel used in vehicle engines.

- Harry Cockburn

Alongside drought, which high temperatures can exacerbate, plants' defences are compromised by heat, leaving them prone to attacks by pathogens and insects. Now, a team of scientists at US and Chinese institutions say they have identified the exact process which leads to faltering plant immunity as temperatures rise, and have worked out a way to stop this process and bolster plants' defences during periods of heat.

The researchers carried out tests on a plant known as thale cress, from the mustard family, which is widely used as a "lab rat" by plant scientists. If the findings are transferable to commonly grown crops, it could help maintain higher yields during extreme weather. The research focuses on a defence hormone called salicylic acid. When plants come under attack from predators or diseases, the levels of salicylic acid rise up to seven-fold. This hormone fires up the plant's immune system and helps them fight off the attack.

However, over certain temperatures plants simply fail to ratchet up their salicylic acid levels, and as a result, are unable to fend off pathogens or pests. This happens as a result of even brief heatwaves, the researcher said.