Releasing the brakes on photosynthesis – Identifying processes impeding photosynthesis in wheat leaves by cutting-edge isotope techniques

ABSTRACTWheat is one of the ‘big three’ cereal crops feeding the world. It contributes substantially to the diet of several billions of people as well as livestock. In Sweden, wheat is grown on more arable land than any other crop.

Wheat belongs to the C3-plant group which contains about 85% of all higher plant species including numerous other important crop species such as rice, soybean, and barley. In C3 plants, net carbon assimilation increases with increasing atmospheric [CO2].

However, maximum rates of carbon assimilation in plants acclimated to elevated [CO2] (475 to 600 ppm) are on average 13% lower than in plants acclimated to ambient [CO2] (350 to 400 ppm).

Research proposed here aims at understanding why wheat and other C3 plants acclimated to elevated [CO2] fall short of their theoretical carbon assimilation potential by identifying the processes that impede carbon assimilation. To this end, carbon fluxes across central leaf metabolism will be quantified by cutting-edge isotope techniques.

Upon identification of the processes impeding photosynthesis, follow-up projects can devise technologies to genetically optimise these processes and thus release the brakes on photosynthesis.

Improving wheat and C3-plant photosynthesis has enormous potential for improving agricultural productivity, food production, and food security both nationally and globally.