Study finds moderate warming rewires one-third of microalga Chlamydomonas reinhardtii genes

On July 10, 2026, researchers from Friedrich Schiller University Jena published a groundbreaking study in The Plant Cell revealing that the microalga Chlamydomonas reinhardtii alters the activity of about one-third of its protein-coding genes in response to moderate temperature changes. This research highlights significant implications for climate change effects on aquatic ecosystems.

Impact of Moderate Temperature Changes on Microalgae

The study indicates that even slight temperature shifts can lead to substantial changes in the gene activity and behavior of C. reinhardtii. Researchers discovered that approximately one-third of the alga's protein-coding genes react to temperature variations, including those related to photosynthesis, metabolism, and locomotion.

For instance, when temperatures rise from 23°C to 28°C (73°F to 82°F), the algal population can achieve a cell density that is 20% higher. However, this increase is accompanied by a reduction in the size of the algae's cilia, which are vital for movement.

Rapid Adaptation of Algal Behavior

The research team, coordinated by Dr. Maria Mittag, found that the algae's swimming behavior adapts within just 15 minutes following a temperature change. According to Dr. Prateek Shetty, the study's first author, "Even before their cell structure is remodeled, they reduce their speed and change direction more frequently." This rapid adaptation demonstrates the microalga's sensitivity to environmental changes.

Additionally, as temperatures increase, C. reinhardtii initially relies on organic carbon sources, delaying the onset of photosynthesis by several days. This change in metabolism could have broader implications for carbon dioxide sequestration and oxygen production in warming aquatic environments.

Collaborative Research Efforts

This study is the result of interdisciplinary collaboration among four research groups within the Cluster of Excellence Balance of the Microverse. By combining expertise, the researchers created a comprehensive understanding of the algae's gene activity, protein composition, motility, and photosynthetic performance.

Dr. Kirsten Küsel, spokesperson for the Cluster, noted, "To fundamentally understand the effects of global phenomena such as climate change, we must start with the smallest actors in our complex ecosystems." This research emphasizes the critical role of microalgae in maintaining ecological balance and highlights the need for further investigation into their responses to climate change.