Location
University of Utah
Start Date
6-12-1996 9:30 AM
Description
Plants grown in microgravity are subject to many environmental stresses, which may promote microbial growth and result in pathogenicity to the plant. Recent plant experiments with super dwarf wheat aboard the NASA Space Shuttle and NASA/Russian Mir Space Station returned from the mission with severe degrees of fungal contamination. Understanding the cause of such microbial contamination and methods to eliminate it are necessary prerequisites for continued plant growth and development studies in micro gravity. A seed-borne fungal endophyte, an Acremonium species was identified in the seed used in both the spaceflight missions and was also recovered from the leaf sheaths of the symptomatic super dwarf wheat that was flown on the 8-day mission aboard U.S. Space Shuttle Discovery (CHROMEX-06, STS-63). The super dwarf wheat infected with the Acremonium endophyte was symptomless when grown under greenhouse conditions. Our data suggest that growth in spaceflight conditions (high relative humidity, high atmospheric carbon dioxide, low light and available nutrients) can induce the transition in the fungus from a symptomless to a pathogenic state on its plant host. Plant growth under spaceflight conditions enabled this Acremonium species to escape its asymptomatic endophytic existence and become pathogenic on super dwarf wheat.
Plant Pathogenicity in Spaceflight Environments
University of Utah
Plants grown in microgravity are subject to many environmental stresses, which may promote microbial growth and result in pathogenicity to the plant. Recent plant experiments with super dwarf wheat aboard the NASA Space Shuttle and NASA/Russian Mir Space Station returned from the mission with severe degrees of fungal contamination. Understanding the cause of such microbial contamination and methods to eliminate it are necessary prerequisites for continued plant growth and development studies in micro gravity. A seed-borne fungal endophyte, an Acremonium species was identified in the seed used in both the spaceflight missions and was also recovered from the leaf sheaths of the symptomatic super dwarf wheat that was flown on the 8-day mission aboard U.S. Space Shuttle Discovery (CHROMEX-06, STS-63). The super dwarf wheat infected with the Acremonium endophyte was symptomless when grown under greenhouse conditions. Our data suggest that growth in spaceflight conditions (high relative humidity, high atmospheric carbon dioxide, low light and available nutrients) can induce the transition in the fungus from a symptomless to a pathogenic state on its plant host. Plant growth under spaceflight conditions enabled this Acremonium species to escape its asymptomatic endophytic existence and become pathogenic on super dwarf wheat.