BIAM researchers have discovered a new approach to enhancing the ability of microalgae to fix and store atmospheric carbon: by modulating the electron management pathways within the chloroplast, it is possible to improve the energy processes associated with photosynthesis. This breakthrough highlights the central role of energy metabolism and opens up new avenues for the synthetic biology of microalgae. Promising applications to meet the challenges of climate change and biotechnology.
Electron circuits at the heart of photosynthetic cells
The chloroplast, the photosynthetic cell’s powerhouse, is responsible for producing ATP and NADPH, often referred to in scientific terms as ‘cellular currency’. Once generated, these forms of energy are either used directly in the chloroplast or exported to other parts of the plant to manufacture cellular components such as proteins, sugars or lipids. To meet the needs of the cell and adapt to environmental variations, the flow of electrons constantly need to be adapted to suit the needs of the cell.
PGRL1 and FLV: major regulators of cellular electron circuits
Researchers at BIAM have recently demonstrated that the PGRL1 and FLV proteins, which are essential to the chloroplast’s electron circuits, play opposing roles during periods of nitrogen deficiency in Chlamydomonas reinhardtii, a model microalga. Although they influence oil storage differently, their modulation enables both oil and starch production to be optimised. The production of these two primary compounds, which are essential for biotechnological applications, can thus be adjusted according to needs, opening the way to new strategies for optimising microalgae for industrial and energy uses.
A lever for innovation
“Most current research has so far focused on increasing the flow of carbon to reinforce its storage as lipids, a key aspect in the development of bioenergies from microalgae. However, it is just as essential to pay attention to energy supply, which plays a vital role in these processes. In this study, we have highlighted new approaches to optimising energy supply, a critical factor in enhancing atmospheric carbon fixation and maximising its storage in the form of lipid droplets produced by microalgae. To illustrate this discovery, we can compare the chloroplast to a car: the organic carbon that are produced by photosynthesis would be the metallic structures, and the cellular energies would play the role of the lubricant. Both are essential to the overall performance of the machine”, explains Yonghua Li-Beisson, head of the EBMP team and co-author of this discovery, who continues: ‘These advances contribute to the progress of research into the development of biotechnologies that can mitigate the effects of climate change, while meeting the energy challenges.
Journal : Plant Physiology. 2024 Nov. https://doi.org/10.1093/plphys/kiae617
Références
Authors : Ousmane Dao1, Adrien Burlacot2,3, Felix Buchert4, Marie Bertrand1, Pascaline Auroy1, Carolyne Stoffel2, Sai Kiran Madireddi2, Jacob Irby2, Michael Hippler4,5, Gilles Peltier1, Yonghua Li-Beisson1*
*Collaboration :
1 Aix Marseille University, CEA, CNRS, Institute of Biosciences and Biotechnology of Aix Marseille, BIAM, CEA Cadarache, Saint Paul-Lez-Durance, 13118, France
2 Department of Plant Biology, The Carnegie Institution for Science, Stanford, CA 94305, USA 3 Department of Biology, Stanford University, Stanford, CA 94305, USA
4 Institute of Plant Biology and Biotechnology, University of Münster, Münster 48143, Germany
5 Institute of Plant Science and Resources, Okayama University, Kurashiki 710-0046, Japan