A collaborative research effort led by Heinrich Heine University Düsseldorf, in partnership with the Max Planck Institute of Molecular Plant Physiology, delves into the intricate role of a specific metabolic pathway in photosynthesis and its potential protective function for plants. Published in Nature Communications, the study explores the implications of these findings for crop plant breeding.
Photosynthesis, a fundamental metabolic process, converts light energy into chemical energy crucial for plant growth and the production of plant-based foods. The study focuses on the interplay between carbon fixation and a metabolic pathway in photosynthesis that competes for resources. The catalyzing protein, Rubisco, plays a pivotal role in this process but has the drawback of generating a toxic by-product, 2-phosphoglycolate, leading to photorespiration.
The researchers aimed to understand whether photorespiration, which expends additional energy, has a protective function for plants, particularly in the face of fluctuating light conditions. The hypothesis posited that photorespiration could counteract photooxidative damage caused by excess light energy.
Thale cress (Arabidopsis thaliana) served as the subject of the study, with specific genes related to photorespiration deactivated in some plants. The researchers exposed these plants to varying light conditions, including fluctuating light and constant light at different intensities.
Contrary to expectations, the study found that photorespiration did not play a crucial role in protecting plants during phases of strong light in fluctuating light conditions. Plants without fully functioning photorespiration appeared to grow better under fluctuating light than under constant light conditions.
Dr. Thekla von Bismarck, lead author of the study, highlighted the unexpected findings, stating, “Photorespiration appears not to play a key role in protecting plants during phases of strong light in fluctuating light conditions.” The research team noted the flexibility of plant metabolism, showcasing the ability to compensate for the lack of certain photorespiratory enzymes through alternative pathways.
The study’s insights hold significance for enhancing crop yields by bypassing photorespiration synthetically. Activating alternative metabolic pathways within chloroplasts could potentially release CO2 from photorespiration, improving photosynthesis under dynamic light conditions. This research contributes valuable knowledge to the ongoing efforts to optimize agricultural practices and enhance crop resilience in changing environmental conditions.