The complex networks and signalling pathways that equip plants to cope with environmental challenges in terrestrial environments developed over evolutionary time. Exposing plants to novel environments presents opportunities to understand how plants adjust to conditions outside their evolutionary experience. Spaceflight is one such environment and understanding how plants function outside of Earth’s boundaries is also integral to space exploration. Plants respond to spaceflight in ways that are dependent on species, ecotype, genetics and even organs. The physiological impact of spaceflight is reflected in the patterns of gene expression. For example, spaceflight-grown Arabidopsis roots tend to be smaller, have fewer lateral roots and shorter root hair development than their terrestrial controls. Aspects of these morphologies in ecotype Columbia (Col-0) suggest a relationship between the down-regulation of several peroxidase genes in spaceflight.

In recent study by Sng et al. and published in AoBP, a spaceflight-induced gene of unknown function was investigated for its potential involvement in ROS-related functions in Arabidopsis roots. Their analysis of how different Arabidopsis plants respond to space resulted in the discovery of a previously uncharacterized gene (OMG1), which was consistently induced in space. This research revealed that OMG1 belongs to the CONSTANS-Like protein family and is involved in maintaining the reactive oxygen species pathway, which appears to be an important feature of the physiological adaptation of plants to the spaceflight environment. It also shows that spaceflight experiments can be used as a platform to discover novel gene function and provide further insights into terrestrial plant biology.

Researcher Highlight

Dr. Anna-Lisa Paul is a Research Professor in the Horticultural Sciences department at the University of Florida, in the program of Plant Molecular and Cellular Biology. Paul is a plant molecular biologist with an interest in how plants respond to abiotic stress, particularly at the gene expression level. Venues associated with spaceflight provide an opportunity to explore plant genomic responses to a novel environment; one that is outside the evolutionary experience of terrestrial organisms. This unique platform presents a background by which adaptive strategies at the gene expression level can be observed as they are adopted to cope with a stress de novo. Paul and her colleague Robert Ferl have launched and analyzed ten spaceflight experiments between 1999 and 2018, which primarily explored the effects of the spaceflight environment on the patterns of gene expression and signal transduction in the model plant Arabidopsis thaliana.

Current research is focused on evaluating the epigenomic responses of Arabidopsisto the spaceflight environment. Paul has also served the space biology community as the Editor in Chief of the journal Gravitational and Space Research, as a member of the ISS Standing Review Board, on the GeneLab Science Council, and as the President of the American Society for Gravitational and Space Research.