The Quenching of Energy (qE) and the CO2 Concentrating Mechanism (CCM) are crucial to the survival of microalgae. Mutants deficient in qE cannot survive exposure to intense light, and mutants deficient in CCM cannot grow photoautotrophically (i.e. using light as an energy source and carbon dioxide as a carbon source) unless supplemented with high levels of CO22. While the two processes have traditionally been studied separately, LPCV researchers have demonstrated that they are largely co-regulated and share common characteristics control elements common.
Until now, the presence of light was considered essential for the activation of qE and CMM. However, this work has unexpectedly shown that the expression of the genes involved in these two processes is largely controlled by the availability of CO2.2. This discovery suggests that the impact of light on the regulation of gene expression is often indirect and reflects changes in intracellular CO2 levels.2defined by the balance between CO22 in chloroplasts and CO2 generation2 by mitochondrial respiration. These observations add a new facet to the role of CO22 in photosynthetic microalgae. So, as well as being a substrate for photosynthesis, CO22 est également une molécule de signalisation qui régule l’expression des gènes en réponse aux changements de lumière et de la disponibilité du CO2.
Ces découvertes permettent de mieux comprendre les mécanismes moléculaires qui régissent le métabolisme du CO2 photosynthétique et peuvent être utilisées pour permettre à la biosphère de réagir plus efficacement à la régulation de la concentration de CO2 dans l’atmosphère, mais aussi de progresser vers une économie durable à faible teneur en carbone pour exploiter pleinement le potentiel biotechnologique des microalgues.