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Measuring Photophysiology of Attached Stage of Colacium sp. by a Cuvette-Type Fast Repetition Rate Fluorometer
Published on: November 12, 2021
Light variability illuminates niche-partitioning among marine Picocyanobacteria
Christophe Six1, Zoe V Finkel, Andrew J Irwin
1Mount Allison University, Sackville, New Brunswick, Canada.
Plos One
|December 20, 2007
Summary
Marine picocyanobacteria like Prochlorococcus and Synechococcus exhibit conserved photoinactivation but variable repair capacities. These differences in photosystem II repair influence their tolerance to light fluctuations and ocean distribution.
Area of Science:
- Marine microbiology
- Oceanography
- Photosynthesis research
Background:
- Prochlorococcus and Synechococcus are key marine primary producers.
- Phytoplankton experience rapid irradiance changes in the ocean's upper mixed layer.
- High light can cause photoinhibition, damaging photosystem II and reducing productivity.
Purpose of the Study:
- To investigate the variability in photosystem II photoinactivation and repair across picocyanobacteria strains.
- To determine how these differences relate to environmental conditions and light tolerance.
- To understand the impact of photoinhibition on picocyanobacteria distribution.
Main Methods:
- Comparative analysis of photosystem II photoinactivation cross-section.
- Assessment of photosystem II repair capacity and protein-specific light capture.
- Correlation of physiological traits with environmental origins of isolates.
Main Results:
- The effective cross-section for photosystem II photoinactivation is conserved.
- Photosystem II repair capacity and light capture are negatively correlated and vary widely.
- Repair rates align with the light and nutrient conditions of the isolates' origin.
Conclusions:
- Picocyanobacteria possess diverse strategies for managing photosystem II damage.
- Repair capacity is a key factor determining tolerance to transient high-light stress.
- Photoinhibition significantly influences the ecological distribution of Prochlorococcus and Synechococcus in the ocean.
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