Adaptation of Photoautotrophs in Extraterrestrial Environments: Responses and Mechanisms of Survival

Abstract

In the last few decades, impeccable progress has been made in the field of astro- biological research whose purpose was to search for efficient Earth organisms capable of surviving in space environment followed by using them as tools for human space exploration. Among the investigated organisms, photoautotrophs constitute the most rigorously studied group. In the present chapter, responses and survival strategies of photoautotrophs in space and/or simulated extraterrestrial conditions have been discussed in detail. Space exposure and survival- related studies on photoautotrophs have mainly been performed using cyanobacteria, algae, lichens and higher plants. Reports accumulated over 60 years reflected that many species belonging to these photoautotrophic groups have an outstanding ability to survive in space. However, the exact mechanisms of their survival in space have not yet been completely explored. In order to unveil the survival strategies of photoautotrophs in space environment, various plant species i.e. Arabidopsis thaliana, Brassica rapa var. nipposinica, Ceratopteris richardii and Oryza sativa, have recently been studied thoroughly through mRNAseq and microarray-based transcriptomic analyses. Results obtained from these studies denoted that plants exhibit a myriad of survival responses like cell wall remodelling, oxidative stress, activation of antioxidative machineries, lipid utilization, cell cycle regulation, increased telomerase activity, reduced genome oxidation, altered hormone signalling, protection of photosynthetic apparatus etc. Few identical responses like oxidative stress, activation of. © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2024.