A team of scientists from University of Glasgow and Zhejiang University has revealed a new, sustainable way for plants to increase CO₂ uptake for photosynthesis while reducing water usage. The breakthrough was led by Prof. Michael Blatt, the Regius Professor of Botany in University of Glasgow and Qiushi Chair Professor of Zhejiang University. The researchers used a new, synthetic light-activated ion channel, engineered from plant and algal virus proteins, to speed up the opening and closing of the stomata – pores in the leaves of plants - through which  CO₂ enters for photosynthesis.

Stomata are also the main route for water loss by plants. Previous attempts to reduce water usage by manipulating these pores has generally come at a cost in CO₂ uptake. The scientists’ modified plants grew as normal and substantially better under light conditions typical of the field, fixing more  CO₂ while losing less water to the atmosphere. This new research now offers a different approach that can successfully improve growth without compromising water use efficiency.

The paper, ‘Optogenetic manipulation of stomatal kinetics improves carbon assimilation, water use, and growth’ is published in Science. The co-authors includ Prof John Christie (Glasgow) and Prof Yizhou Wang (Zhejiang University)