ANALYSIS OF A NOVEL SENSORY MECHANISM IN ROOT PHOTOTROPISM (TROPI)
Research Area: Plant Biology
Expedition(s): 21, 22, 23, 24, 27 and 28
Principal Investigator(s): ● John Z. Kiss, PhD, Miami University, Oxford, Ohio
RESEARCH OBJECTIVES
Analysis of a Novel Sensory Mechanism in Root Phototrpism (Tropi) studies Arabidopsis
thaliana plants sprouting from seeds to gain insights into sustainable agriculture for future
long-duration space missions.
EARTH BENEFITS
Further understanding of how plants grow and develop at a molecular level can lead to
significant advancements in agricultural production on Earth.
SPACE BENEFITS
During long-term space exploration, it is necessary to provide crew members with regenerative
sources of food, as well as supplemental methods to recycle carbon dioxide into breathable
oxygen. As new information about how plants grow in microgravity emerges, sustainable plant-
based life support systems may be
developed.
RESULTS
Tropi was a multi-part experiment
aimed to gain a better understanding
of how microgravity affects
phototropism, directed growth of a
plant in response to a light stimulus,
and gravitropism, directed growth in
response to gravity, in Arabidopsis
thaliana. An in space experiment was
necessary because the microgravity
conditions of space provide the
opportunity to study phototropism in
the absence of gravity (Correll 2005).
Tropi was initially performed during Increment 14 on the International Space Station (ISS).
These experiments were returned to Earth on 3 space shuttle missions. Several important
lessons were gained from this initial run. The first issue arose while using analog video tapes.
Although quality images were taken, there was an inefficient use of resources in the time it
took for image processing and analysis procedures to be performed. Another issue arose during
ISS022E087465 - NASA astronaut Jeffrey Williams, Expedition 22
commander, services the Tropism in Plants (TROPI2) experiment
in the Columbus Laboratory of the International Space Station.