Plant growth in microgravity for BLSS: general issues and the Italian contribution

Plants are among the key organisms in Bioregenerative Life Support Systems (BLSS) in Space because they have a role in the regeneration of resources and in the psychological support of the crew. The design of an efficient BLSS cannot be irrespective of the profound knowledge of the functioning of the vegetal systems under the effect of Space factors. From an evolutionary perspective, reduced gravity can be considered one of the factors driving the evolution of plants in Space. In this paper, we outline the need for plant-based BLSS to sustain exploratoryclass manned missions in Space. After some evolutionary considerations about future plant development in Space, we also report a synthesis of the results of case studies performed by Italian research groups aiming to understand the effects of simulated or real microgravity on various aspects of plant growth and reproduction. We conclude by emphasizing how plant research in Space should address both the improvement of the knowledge of basic biological processes and the development of new agro-technologies. Efforts to engage in a multidisciplinary approach to understand the effects of Space factors on plant growth are needed considering that such factors affect the biological systems contemporarily at molecular, biochemical, morphostructural and physiological levels.