Synergistic effects of temperature and light on photoprotection in the model diatom Phaeodactylum tricornutum

Physiologia Plantarum, Journal Year: 2025, Volume and Issue: 177(1)

Published: Jan. 1, 2025

Abstract Diatoms dominate phytoplankton communities in turbulent waters, where light fluctuations can be frequent and intense. Due to this complex environment, these heterokont microalgae display remarkable photoprotection strategies, including a fast Non‐Photochemical Quenching (NPQ). However, nature, several abiotic parameters (such as temperature) influence the response of photosynthetic organisms stress synergistic or antagonistic manner. Yet, combined effects other drivers on photoprotective capacity diatoms are still poorly understood. In work, we investigated impact short‐term temperature model diatom Phaeodactylum tricornutum , combining NPQ induction‐recovery assays curves with broad gradient superimposed treatments (5 35°C). We employed mutant lines deficient generation ( vde KO ) recovery zep3 wild type. found that have effect: lower temperatures limited both NPQ, while general photophysiological performance was enhanced warming, up heat‐stress limit (above 30°C). discuss induction propose independent from energy requirements cells result altered xanthophyll cycle dynamics. Namely, de‐epoxidation activity strongly increases temperature, outweighing epoxidation resulting positive increase temperature. Finally, time frame, not effect, relationship between increasing NPQ.

Language: Английский

UVR regulation of photoprotection in Phaeodactylum tricornutum (Bacillariophyceae): roles of light energy doses

Photosynthesis Research, Journal Year: 2025, Volume and Issue: 163(3)

Published: April 15, 2025

Language: Английский

The Xanthophyll Cycle balances Photoprotection and Efficiency in the seawater alga Nannochloropsis oceanica

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: Nov. 3, 2024

Abstract Photosynthetic reactions require continuous modulation to respond highly dynamic environmental conditions. Regulation of photosynthesis involves various mechanisms, which differ across phylogenetic groups. One such mechanism, found widespread in photosynthetic eukaryotes, is the xanthophyll cycle, reversible light-dependent conversion between carotenoids violaxanthin, antheraxanthin, and zeaxanthin. In this study, we investigated impact cycle Nannochloropsis oceanica , a seawater microalga member Eustigmatophyta that features peculiarly high content xanthophylls. We generated characterized lines with increased levels enzymes involved i.e. violaxanthin de-epoxidase (VDE) zeaxanthin epoxidase (ZEP) demonstrated their main factor controlling overall reaction rates dynamics cycle. Subsequent differences profile affect activation photoprotection mechanisms as non-photochemical quenching tolerance reactive oxygen species. Interestingly, overexpression VDE expands limits light tolerance, whereas ZEP facilitates faster recovery after exposure but also heightened photosensitivity under some These findings underscore critical role regulation Nannochloropsis, where it not simply mechanism excess illumination, plays central modulating photosynthesis, fulfilling complex task balancing light-use efficiency different

Language: Английский