Early Responses to Microbial Patterns in Chlamydomonas reinhardtii
Background:
In plants, recognition of conserved microbial patterns triggers rapid cellular responses, including transient increases in cytosolic calcium and the production of reactive oxygen species (ROS). Although green algae, like plants, associate with diverse microbiota in nature, it remains largely unknown whether they perceive conserved microbial cues in a comparable manner. The unicellular model alga Chlamydomonas reinhardtii, for example, recruits soil microbiota into its immediate microenvironment, known as the phycosphere, and forms mutualistic interactions with diverse yeasts and filamentous fungi. Moreover, recent studies have shown that stress-induced ROS signalling is conserved in C. reinhardtii, suggesting that key signalling components may have evolved before the emergence of land plants. Whether these signalling pathways also mediate the perception of microbial cues in green algae remains unknown.
C. reinhardtii forms a mutualistic interaction with the soil-borne fungus Verticillum dahliae. However, the algal signaling components and molecular mechanisms governing this interaction remain unknown.
Project Description:
This project aims to test whether Chlamydomonas reinhardtii mounts rapid cellular responses to conserved microbial patterns. The student will expose algal cultures to crude microbial extracts and selected microbe-associated molecular patterns, such as chitin- and glucan-derived molecules or bacterial elicitors, and monitor early responses in the alga. The main objective will be to establish and optimize assays for detecting cytosolic calcium dynamics and ROS production in C. reinhardtii. These experiments will provide a basis for investigating whether immune-like microbial perception mechanisms are conserved in unicellular green algae and may contribute to algal–microbial interaction outcomes.
Technologies and Methods:
Cultivation of Chlamydomonas reinhardtii
Treatment with conserved microbial patterns
Calcium signalling assays using an aequorin-based reporter strain
ROS detection assays using fluorescent probes
Microplate reader-based assay optimization
Data analysis and visualization in R or Python
Supervisor: Hanna Rövenich
Relevant literature:
Prockl et al. (2026) The model alga Chlamydomonas reinhardtii forms mutualistic interactions with Verticillium fungi. bioRxiv, doi:10.64898/2026.05.20.726472.