A constitutive stress response is a result of low temperature growth in the Antarctic green alga Chlamydomonas sp. UWO241. (2nd November 2021)

• Record Type: Journal Article
• Authors: Cvetkovska, Marina; Zhang, Xi; Vakulenko, Galyna; Benzaquen, Samuel; Szyszka‐Mroz, Beth; Malczewski, Nina; Smith, David R.; Hüner, Norman P.A.
• Is Part Of: Plant, cell and environment. Volume 45:Number 1(2022)
• Page Start: 156
• Page End: 177
• Publication Date: 2021-11-02
• Subjects: cold adaptation -- heat stress -- metabolism -- psychrophile -- transcriptome; Plant physiology -- Periodicals; Plant cells and tissues -- Periodicals; Plant communities -- Periodicals; 581.105
• DOI: 10.1111/pce.14203
• Languages: English
• ISSNs: 0140-7791

Abstract

Abstract: The Antarctic green alga Chlamydomonas sp. UWO241 is an obligate psychrophile that thrives in the cold (4–6°C) but is unable to survive at temperatures ≥18°C. Little is known how exposure to heat affects its physiology or whether it mounts a heat stress response in a manner comparable to mesophiles. Here, we dissect the responses of UWO241 to temperature stress by examining its growth, primary metabolome and transcriptome under steady‐state low temperature and heat stress conditions. In comparison with Chlamydomonas reinhardtii, UWO241 constitutively accumulates metabolites and proteins commonly considered as stress markers, including soluble sugars, antioxidants, polyamines, and heat shock proteins to ensure efficient protein folding at low temperatures. We propose that this results from life at extreme conditions. A shift from 4°C to a non‐permissive temperature of 24°C alters the UWO241 primary metabolome and transcriptome, but growth of UWO241 at higher permissive temperatures (10 and 15°C) does not provide enhanced heat protection. UWO241 also fails to induce the accumulation of HSPs when exposed to heat, suggesting that it has lost the ability to fine‐tune its heat stress response. Our work adds to the growing body of research on temperature stress in psychrophiles, many of which are threatened by climate change. Abstract : The Antarctic Chlamydomonas sp. UWO241 constitutively accumulates stress‐related metabolites and proteins due to its extremophilic lifestyle, but it has lost the ability to fine‐tune its heat stress response. Our work helps understand psychrophiles, many of which are threatened by climate change.