Researchers at the Australian National University have uncovered a strategy that helps plants continue photosynthesising under extreme heat and dry air conditions.

The study is the first to successfully separate the effects of heat and air dryness on photosynthesis across different CO2 levels, which could have significant practical implications for agriculture helping to improve crop management strategies and strengthen food security.

The research shows plants can coordinate multiple internal processes to stabilise the amount of CO2 reaching the chloroplast, even during stressful environmental conditions.

Lead researcher Dr Xingyu Hu from the Research School of Biology said the findings challenge long-held assumptions about how plants respond to climate stress.

“Scientists have traditionally believed that dry air suppresses photosynthesis mainly because plants close their stomata, which limits the amount of CO2 entering the leaf,” Dr Hu said.

“Our research shows the important but long-overlooked role of another process inside the leaf in buffering the effects of heat and air dryness on the CO2 environment at the site of photosynthesis.