According to a study conducted by The University of Western Australia, plants can make their own 'secret decisions' about how much carbon can be released back into the atmosphere. According to the study published in Nature Plants, the discovery has "profound implications" for the use of plants as carbon stores.
It implies that future plants could be designed to meet the world's food needs while also benefiting the environment.
"We discovered that plants control their respiration in unexpected ways; they control how much carbon from photosynthesis they keep to build biomass by using a metabolic channel," University of Western Australia plant biochemist and study author Harvey Millar told ScienceAlert.
"This occurs just before they decide to burn a compound called pyruvate to produce and release CO2 back into the atmosphere." The process was discovered while working on thale cress, a classic plant model organism (Arabidopsis thaliana).
The researchers, led by plant molecular scientist Xuyen Le from the University of Western Australia, labelled pyruvate with C13 (a carbon isotope) to track where it was shifted during the citric acid cycle and discovered that pyruvate from different sources was used differently.
This means that the plant can actually track down the source of the pyruvate and decide whether to release it or keep it for other purposes.
"We discovered that a transporter on mitochondria directs pyruvate to respiration to release CO2, but pyruvate produced in other ways is retained by plant cells to build biomass – if the transporter is blocked, plants use pyruvate from other pathways for respiration," Le explained to Science Alert.
"The preferred source for citrate production was imported pyruvate." According to the study, this ability to make decisions violates the normal rules of biochemistry, in which every reaction is a competition and the processes have no control over where the product goes.
"Metabolic channelling violates these rules by revealing reactions that do not behave like this, but are set decisions in metabolic processes that are shielded from other reactions," Millar explains.
