Growing maize on Mars: Effects of Irradiation Induced Transposable Element Activity on Plant Survival and Development

Abstract

<p>It was hypothesized by Barbara McClintock that Transposable Elements (TEs) can become activated by conditions that “shock” the genome (McClintock 1984). TEs, which are sometimes referred to as Jumping Genes, are segments of DNA that have the ability to copy themselves and move within the genome. TEs are found in all organisms, but they are usually kept in an inactive state by host defense mechanisms. We set out to determine if radiation will induce TE activity in the maize genome. The results may indicate the feasibility of growing crops in space, particularly whether the genome will be stable over multiple generations. In addition, the results may indicate the effects of increased radiation and climactic challenges on crop plants here on Earth. Maize (p1-wwB54) seedlings were first irradiated by both UV and X-rays according to conditions similar to the Martian atmosphere. Currently, phenotypic data indicates that root, shoot, and leaf development are drastically affected by radiation ranging from 25 Gy to 250 Gy. The data also suggests that the stage of the seedling at the time of irradiation and the time of planting after irradiation are major factors in plant survival. Future plans include preparing and sequencing genomic DNA samples from both irradiated and control seedlings. The sequences will then undergo analysis by bioinformatic methods to identify new mutations caused directly by radiation and indirectly through the activation of TEs.</p> <p>References:<br />McClintock, B. 1984. The significance of responses of the genome to challenge. Science 226: 792-801.</p>