A recent study has uncovered how cadmium (Cd) affects the carbon fixation process in rice, leading to reduced growth. Researchers found that Cd competes with magnesium (Mg) to bind to the enzyme Rubisco, crucial for photosynthesis.
The presence of Cd displaces Mg, which shifts Rubisco”s activity from a carboxylation process to an oxygenation process. This change causes the accumulation of 2-phosphoglycolate (2-PG), which enhances photorespiration.
As a result of increased photorespiration, there is a significant release of carbon dioxide (CO2), which diminishes the net fixation of CO2 in the rice plants. This disruption in the carbon fixation mechanism ultimately contributes to stunted growth in rice, emphasizing the detrimental impact of cadmium contamination in agricultural systems.
