Integrated photochemical and transcriptomic responses reveal an adaptive strategy of the Antarctic snow alga Chlorominima collina (Chlorophyta) for surviving freezing and darkness

Gálvez, FE, Silva, AX, Huovinen, P, Figueroa, A, Morales-Torres, DF and Gómez, I 2026 Integrated photochemical and transcriptomic responses reveal an adaptive strategy of the Antarctic snow alga Chlorominima collina (Chlorophyta) for surviving freezing and darkness. Environmental and Experimental Botany. 10.1016/j.envexpbot.2026.106440

Full text not available from this repository.

Abstract/Summary

Snow algae are essential primary producers and carbon sinks in the cryosphere. Disentangling the physiological and molecular responses of these organisms to acute abiotic stress induced by snow dynamics is imperative for revealing survival strategies that sustain the snow microbiome under the extreme conditions of polar regions. Here, we examine the tolerance to a short-term (4 h) freezing condition (-20°C) in darkness, followed by a recovery period, in the Antarctic snow alga Chlorominima collina. The responses were analyzed in contrast to a light control (2 °C) by integrating chlorophyll fluorescence of PSII, mRNA-sequencing and oxidative stress detection. The treated cells reduced PSII photochemical efficiency and suppressed the light harvesting process. Simultaneously abiotic stress-responsive genes were expressed, suggesting a reprograming of metabolism and processes, orchestrated by key signaling pathways and transcription factors. This profile revealed common elements of states prior to hypometabolism such as the fuel switch from carbohydrate to lipid catabolism, improved defenses, repression of biosynthetic processes, induction of mitophagy and autophagy, and regulation of transcription and translation. These adjustments promoted the maintenance of cellular homeostasis, as evidenced by enrichment of this process and the recovery of PSII efficiency. Therefore, we proposed that the integration of the reduction of efficiency with which PSII captures energy and the regulation of genes involved in the induction of hypometabolism constitutes an adaptive strategy that confers freezing and darkness tolerance at snow algae. Collectively, the observed functional changes may be relevant for understanding the survival and subsequent adaptation of Chlorophyta to the Antarctic snow environment

Item Type:	Publication - Article
Additional Keywords:	Antarctic, freezing, darkness, light-harvesting, hypometabolism, homeostasis, photosynthesis, snow algae
Subjects:	Botany
Divisions:	Marine Biological Association of the UK > Other (MBA)
Depositing User:	Ms Kristina Hixon
Date made live:	30 Oct 2026 12:00
Last Modified:	30 Oct 2026 12:00
URI:	https://plymsea.ac.uk/id/eprint/10677

Actions (login required)

View Item