Beyond the extremes: Rocks as ultimate refuge for fungi in drylands

• Published in: Mycologia
• Main Authors: Coleine, Claudia, Stajich, Jason E., Ríos, Asunción de los, Selbmann, Laura
• Other Authors: Ministerio de Ciencia e Innovación (España), European Commission
• Format: Article in Journal/Newspaper
• Language: English
• Published: Taylor & Francis 2021
• Subjects: Antarctica; Climate change; Dry limits of life; Drylands; Endolithic communities; Extreme environments; Fungi; Rocks; Antarctic; Antarc*
• Online Access: http://hdl.handle.net/10261/240400; https://doi.org/10.1080/00275514.2020.1816761; https://doi.org/10.13039/501100000780; https://doi.org/10.13039/501100004837

In an era of rapid climate change and expansion of desertification, the extremely harsh conditions of drylands are a true challenge for microbial life. Under drought conditions, where most life forms cannot survive, rocks represent the main refuge for life. Indeed, the endolithic habitat provides thermal buffering, physical stability, and protection against incident ultraviolet (UV) radiation and solar radiation and, to some extent, ensures water retention to microorganisms. The study of these highly specialized extreme-tolerant and extremophiles may provide tools for understanding micro-bial interactions and processes that allow them to keep their metabolic machinery active under conditions of dryness and oligotrophy that are typically incompatible with active life, up to the dry limits for life. Despite lithobiontic communities being studied all over the world, a comprehensive understanding of their ecology, evolution, and adaptation is still nascent. Herein, we survey the fungal component of these microbial ecosystems. We first provide an overview of the main defined groups (i.e., lichen-forming fungi, black fungi, and yeasts) of the most known and studied Antarctic endolithic communities that are almost the only life forms ensuring ecosystem functionality in the ice-free areas of the continent. For each group, we discuss their main traits and their diversity. Then, we focus on the fungal taxonomy and ecology of other worldwide endolithic communities. Finally, we highlight the utmost importance of a global rock survey in order to have a comprehensive view of the diversity, distribution, and functionality of these fungi in drylands, to obtain tools in desert area management, and as early alarm systems to climate change. C.C. and L.S. wish to thank the Italian National Program for Antarctic Research for funding sampling campaigns and research activities in Italy in the framework of Italian National Program for Antarctic Researches (PNRA) projects. The Italian Antarctic National Museum (MNA) is acknowledged ...