Bet hedging in a unicellular microalga

• Published in: Nature communications 2024-03, Vol.15 (1), p.2063-2063, Article 2063
• Main Authors: Tang, Si, Liu, Yaqing, Zhu, Jianming, Cheng, Xueyu, Liu, Lu, Hammerschmidt, Katrin, Zhou, Jin, Cai, Zhonghua
• Format: Article
• Language: English
• Subjects: 14/28; 14/63; 45/91; 631/158/855; 631/181/2468; Adaptation; Algae; Aquatic microorganisms; Biological Evolution; Carbon sinks; Cell Division; Cell walls; Ecological adaptation; Ecological function; Ecosystem; Ecosystem conservation; Environmental conditions; Gene expression; Haematococcus pluvialis; Humanities and Social Sciences; Humans; Microalgae; multidisciplinary; Photosynthesis; Reproduction; Science; Science (multidisciplinary); Stochasticity
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-024-46297-6

Understanding how organisms have adapted to persist in unpredictable environments is a fundamental goal in biology. Bet hedging, an evolutionary adaptation observed from microbes to humans, facilitates reproduction and population persistence in randomly fluctuating environments. Despite its prevalence, empirical evidence in microalgae, crucial primary producers and carbon sinks, is lacking. Here, we report a bet-hedging strategy in the unicellular microalga Haematococcus pluvialis . We show that isogenic populations reversibly diversify into heterophenotypic mobile and non-mobile cells independently of environmental conditions, likely driven by stochastic gene expression. Mobile cells grow faster but are stress-sensitive, while non-mobile cells prioritise stress resistance over growth. This is due to shifts from growth-promoting activities (cell division, photosynthesis) to resilience-promoting processes (thickened cell wall, cell enlargement, aggregation, accumulation of antioxidant and energy-storing compounds). Our results provide empirical evidence for bet hedging in a microalga, indicating the potential for adaptation to current and future environmental conditions and consequently conservation of ecosystem functions. Bet hedging is an evolutionary strategy facilitating survival in randomly fluctuating environments. Here, the authors report bet hedging in the unicellular microalga Haematococcus pluvialis , undergoing reversible diversification into mobile and non-mobile cells.