The Multiplanetary Future of Plant Synthetic Biology

Abstract

The interest in human space journeys to distant planets and moons has been re-ignited in recent times and there are ongoing plans for sending the first manned missions to Mars in the near future. In addition to generating oxygen, fixing carbon, and recycling waste and water, plants could play a critical role in producing food and biomass feedstock for the microbial manufacture of materials, chemicals, and medicines in long-term interplanetary outposts. However, because life on Earth evolved under the conditions of the terrestrial biosphere, plants will not perform optimally in different planetary habitats. The construction or transportation of plant growth facilities and the availability of resources, such as sunlight and liquid water, may also be limiting factors, and would thus impose additional challenges to efficient farming in an extraterrestrial destination. Using the framework of the forthcoming human missions to Mars, here we discuss a series of bioengineering endeavors that will enable us to take full advantage of plants in the context of a Martian greenhouse. We also propose a roadmap for research on adapting life to Mars and outline our opinion that synthetic biology efforts towards this goal will contribute to solving some of the main agricultural and industrial challenges here on Earth.

Harnessing synthetic biology for kelp forest conservation1

“…For example, in the case of temperature tolerance (a goal commonly approached in synthetic biology to address issues relating to drought tolerance in crops; Llorente et al. ), kelp gametophytes appear to tolerate temperatures well above the maximum experienced in the field (Novaczek , Mohring et al. ), suggesting this life stage may not be as limited by high temperatures as sporophytes (Wernberg et al.…”

“…Second, given manipulation of genes at any life stage will be heritable, how this manifests between gametophyte and sporophyte stages remain largely unknown. For example, in the case of temperature tolerance (a goal commonly approached in synthetic biology to address issues relating to drought tolerance in crops; Llorente et al 2018), kelp gametophytes appear to tolerate temperatures well above the maximum experienced in the field (Novaczek 1984, Mohring et al 2014, suggesting this life stage may not be as limited by high temperatures as sporophytes ). However, whether these tolerances are heritable or plastic, and how different life stages respond to other stressors are unknown, presenting major challenges when targeting genes for manipulation.…”

The Synthetic Biology Toolkit for Photosynthetic Microorganisms

“…Photoautotrophic production may be required for applications in desert and extraplanetary (i.e. beyond Earth) environments (Llorente et al, 2018). Achieving sufficient light penetration into cultures without loss of the growth medium (especially in high-density cultures required for high titers) also represents a challenge in bulk production systems.…”

Synthetic Biology for Terraformation Lessons from Mars, Earth, and the Microbiome

“…Similarly, recent decades have witnessed the development of synthetic biology as an engineering avenue for modifying cells to perform novel functionalities [92]. This area promises the modification of living systems in ways that could overcome the design limitations resulting from evolutionary trade-offs [93,94]. Could engineered microorganisms be the key for planetary terraforming?…”