Biological Research In Canisters -16: Actin Regulation of Arabidopsis Root Growth and Orientation During Space Flight (BRIC-16-Regulation) - 12.10.14
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Biological Research In Canisters - 16: Actin Regulation of Arabidopsis Root Growth and Orientation During Space Flight (BRIC-16-Regulation) studies how actin cytoskeleton dictates root growth orientation during space flight and conducts an extensive set of genome-wide microarray studies to unravel actin-dependent gene regulatory networks that modulate root growth and orientation during space flight.
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Bionetics Corporation, Cape Canaveral, FL, United States
Sponsoring Space Agency
National Aeronautics and Space Administration (NASA)
Human Exploration and Operations Mission Directorate (HEOMD)
ISS Expedition Duration
March 2010 - September 2010
Previous ISS Missions
ISS Expedition 23/24 is the first mission for BRIC-16-Regulation.
- BRIC-16-Regulation focuses on Arabidopsis, the preferred model species for plant investigations in space. Arabidopsis is a small plant with a short generation time and the advantages of a small genome size, a wealth of available genetic mutants, and an already well characterized pattern of development.
- BRIC-16 flies Arabidopsis seeds on a Space Shuttle mission during which the seeds will germinate grow, and are subsequently returned to Earth when the Space Shuttle lands. Crewmembers will perform an inflight chemical fixation to preserve the seedlings on-orbit prior to return.
- These investigations will study how plants perceive and respond to gravity, and how gene regulation is altered by space flight conditions. The fundamental knowledge gained through these investigations will aid in our ability to better control plant use on Earth in agriculture (and other) applications.
Providing a continuous supply of food, oxygen, and clean water for humans in space is a costly proposition. To date these needs have been met largely through stowage and resupply. As the durations of missions increase, the costs associated with this approach become prohibitive. For this reason, virtually all scenarios for long-term space missions involve plants as key components of the life support environment. Plants will be used to recycle wastes, remove carbon dioxide, purify water and produce oxygen and food for astronauts Biological Research In Canisters - 16: Actin Regulation of Arabidopsis Root Growth and Orientation During Space Flight (BRIC-16-Regulation) examines how the actin cytoskeleton dictates root growth orientation during space flight. The guiding hypothesis is that actin filaments (F-actin) negatively regulate environmental and endogenous signals to specify root orientation on Earth and in space. This hypothesis is based on previous ground based research demonstrating that F-actin disruption enhances the sensitivity of roots to gravity. Arabidopsis seedlings with a transfer (T)- DNA mutation in a vegetative actin isoform (act2) and the short-duration microgravity environment provided by a Space Shuttle mission are used to test the hypothesis. Microgravity is an essential component of the experiment since it will help determine the impact of other signals on root orientation that are typically masked by the strong gravitational force on Earth. Root orientation and amyloplast position of dark-grown act2 and wild-type seedlings are quantified. In parallel, an extensive set of genome-wide microarray studies using gene arrays to unravel actin-dependent gene regulatory networks that modulate root growth and orientation during space flight are conducted. We expect to collect data that will pave the way for an in depth understanding of plant growth under microgravity conditions.
The fundamental knowledge gained by growing plants under microgravity conditions can contribute to resolving the following risks:
- Providing and Maintaing Biodegenerative Life Support Systems
- Maintaining Food Quantity and Quality
- Maintaining Acceptable Atmosphere
- Managing Waste
- Providing and Recovering Potable Water
The microgravity of space will be used to investigate and clarify plant-related phenomena that cannot be studied in the presence of gravity. The fundamental knowledge gained through these investigations will aid in our understanding of basic plant processes that can eventually increase our ability to better control plant use on Earth in agriculture (and other) applications.
This is a passive payload, with no on-orbit power or communications available. The investigators will plate their biology onto 60 mm petri dishes containing agar-solidified media. Each petri dish will be placed inside its own Petri Dish Fixation Unit (PDFU). The PDFUs will be assembled and loaded with a fixative in the fluid compartment. Five PDFUs plus one temperature data logger will be loaded into each BRIC-PDFU (Biological Research In Canisters - Petri Dish Fixation Unit). Preflight turnover will be 26 hours prior to launch. In the event of a launch scrub, the entire assembly will be replaced with an identical back-up unit with freshly loaded biology. Crewmembers will perform one in-flight operation per petri dish (using actuator equipment) to chemically fix the tissues on-orbit prior to return (using Glutaraldehyde and RNAlater). The PDFUs will remain contained within the BRIC-PDFUs during all phases of flight operations. The fixed samples will be subsequently returned to Earth for postflight processing..
Eight BRIC-PDFU canisters reside in ½ middeck locker drawer. During Actuation operations, the drawer is removed, and the BRIC canisters removed one at a time. The Actuator Tool and Rod Kit are removed from another middeck locker location. A single rod from the rod kit is inserted into the Actuator Tool. The Actuator Tool is used to insert the rod into a single location on a BRIC canister lid. Squeezing the handle on the Actuator Tool forces the rod through septa on the BRIC canister lid, then through septa on one of the PDFUs inside the canister. The rod forces a piston inside the PDFU to move fixatives from a storage volume into the Petri dish volume inside the PDFU. After Actuation, the rod remains contained inside the BRIC canister. The crew do not come in contact with fixatives, which remain contained within 3 levels of containment throughout all phases of flight. The Actutation is repeated for all 5 PDFU locations within each of the eight BRICs, totaling 40 PDFUs, and 40 Actutations. The Actuation procedure is performed in 30 minutes. For the remainder of flight, the BRIC operates autonomously with no crew interface.
Ground Based Results Publications
Dyachok J, Sparks JA, Liao F, Wang Y, Blancaflor E. Fluorescent protein-based reporters of the actin cytoskeleton in living plant cells: fluorophore variant, actin binding domain, and promoter considerations. Cytoskeleton . 2014 May; 71(5): 311-327.
Ground studies show that roots of knock-outs to the vegetative ACT2 gene display stronger curvature responses when provided with a 30 min horizontal gravistimulation followed by rotation for 5 h on a 2-D clinostat (courtesy of E. Blancaflor)
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A. View of a PDFU on its side (launch position). B. Five PDFUs plus one temperature logger within a BRIC-PDFU canister prior to closure. C. BRIC-PDFU canister with two pin guards attached. D. Eight BRIC-PDFU canisters stowed within a half middeck locker (as flown on STS-131).
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Injection of fluids into PDFU petri dishes. A. Actuator Rod Kit and Actuator Tool. B. Actuator Tool attached to BRIC-PDFU canister after using the Actuator to push fluid into the PDFU.
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