Biological Research In Canisters - 16: Investigations of the plant cytoskeleton in microgravity with gene profiling and cytochemistry (BRIC-16-Cytoskeleton) - 09.17.14
ISS Science for Everyone
Science Objectives for Everyone
Biological Research In Canisters - 16: Investigations of the plant cytoskeleton in microgravity with gene profiling and cytochemistry (BRIC-16-Cytoskeleton) studies the effects of microgravity on the structure and organization of the actin cytoskeleton in plants using the model plant Arabidopsis. The specific aims of this research are: to investigate plastid position in statocytes (the gravity-perceiving cells) in microgravity; to determine the effect of microgravity on the actin cytoskeletal organization in gravity-perceiving cells; (3) to study microgravity effects on actin cytoskeleton-related gene expression in plant cells.
Science Results for Everyone
Seedling cells seem to grow the same in space as on the ground – until you look closely. Scientists analyzed 13 samples that spent 309 hours in total darkness in microgravity and found no major discrepancies in structure between ground and flight controls for plants grown in darkness. But researchers did find two major differences: roots systems of space-grown seedlings showed more skewing at the roots, and the amount of adventitious roots (roots formed from shoot tissues) varied greatly between flight and ground samples. This and previous experiments suggest that microgravity may alter essential cell functions related to cell cycle regulation.
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 - October 2015
Previous ISS Missions
ISS Expedition 23/24 is the first mission for BRIC-16-Cytoskeleton.
- This payload 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 and grow until returned to Earth on the Space Shuttle. Crewmembers will perform an in-flight chemical fixation to preserve the tissues on-orbit prior to return.
- These investigations will study how plants perceive and respond to gravity, and how gene regulation is altered by spaceflight 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 BRIC-16-Cytoskeleton studies the effects of microgravity on the structure and organization of the actin cytoskeleton in plants. This investigation builds on previous ground-based and space flight research using the model plant Arabidopsis. Thus, the specific aims of this proposed flight research are to investigate plastid position in statocytes (the gravity-perceiving cells) in microgravity; to determine the effect of microgravity on the actin cytoskeletal organization in gravity-perceiving cells and to study microgravity effects on actin cytoskeleton-related gene expression in plant cells. This investigation allows direct correlation of the results from cytological investigations and gene profiling in order to understand the nature of the actin cytoskeleton in mechanisms of gravity perception. This research focuses on the effects of gravity on basic cellular mechanisms and processes in plants. Improved knowledge of the basic mechanistic processes that will be the focus of this research is vital to develop ways to use plants in extraterrestrial bioregenerative life support systems.
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 and
- 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 fluid in the syringe department (as specified by the selected investigators). 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 no earlier than 24 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, RNAlater, and Formaldehyde). 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, since the fluids 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.
The BRIC-16-Cytoskeleton experiment was carried into space on April 5, 2010 and returned April 20, 2010, aboard orbiter Discovery on space shuttle mission STS-131 as part of the BRIC-16 suite of investigations. A total of 13 PDFU samples were studied in flight and on ground. These samples were allotted approximately 309 hours in total darkness to grow in microgravity and then fixated for later observation. The primary focus of this experiment is to focus on the changes in composition of the seedlings in microgravity.
Seedling morphology did not develop with any major discrepancies. With controlled temperatures, averaging within 22-25ºC, seedling germination between the ground and flight controls remained comparable with 90.9% for the ground controls and 89.0% for the flight controls. When comparing ground and flight experiments, both exhibited an etiolated appearance, elongated hypocotyls, which is typical for plants grown in darkness.
The BRIC-16-Cytoskeleton experiment found two major differences of note between ground and inflight samples. The first difference arose in the morphology found in the roots systems of the seedlings. Extreme skewing was observed at the root apex and proximal root. The roots skewed only slightly on the ground controls in comparison to flight controls. This leads to the conclusion that plants have endogenous growth patterns that are largely masked in normal 1 g conditions found on Earth. Another major difference was noted between the amount of adventitious roots (roots formed from shoot tissues) found on the flight and ground samples. This adds to the idea that microgravity produces an increase in mitosis in the pericycle, thus producing a larger number of adventitious roots. It is also believed that with previous and present experiments that microgravity may induce alterations in essential cell functions that may be related to cell cycle regulation (Millar et al. 2011).
Millar KD, Millar KD, Johnson CM, Edelmann RE, Kiss JZ, Kiss JZ. An Endogenous Growth Pattern of Roots Is Revealed in Seedlings Grown in Microgravity. Astrobiology. 2011 Oct; 787-797(8): 1-12.
Ground Based Results Publications
Kiss JZ, Kiss JZ, Brinkmann E, Brillouet C. Development and Growth of Several Strains of Arabidopsis Seedlings in Microgravity. International Journal of Plant Sciences. 2000; 161: 55-62.
Kiss JZ, Kiss JZ, Edelmann RE, Wood PC. Gravitropism of hypocotyls of wild-type and starch-deficient Arabidopsis seedlings in spaceflight studies. Planta. 1999; 209: 96-103.
Kiss JZ, Kiss JZ, Kumar P, Bowman RN, Steele MK, Eodice MT, Correll MJ, Edelmann RE. Biocompatibility studies in preparation for a spaceflight experiment on plant tropisms (TROPI). Advances in Space Research. 2007; 39(7): 1154-1160. DOI: 10.1016/k.asr.2006.12.017.
Mullen JL, Correll MJ, Hangarter RP. Phytochromes A and B mediate red-light-induced positive phototropism in roots. Plant Physiology. 2003; 131: 1411-1417.
Kiss JZ, Kiss JZ, Wright JB, Casper T. Gravitropism in roots of intermediate-starch mutants of Arabidopsis. Plant Physiology. 1996; 97: 237-244.
Kiss JZ, Kiss JZ. Mechanisms of the early phases of plant gravitropism. Critical Reviews in Plant Sciences. 0; 19: 551-573.
Kiss JZ, Kiss JZ, Kumar P, Millar KD, Millar KD, Edelmann RE, Correll MJ. Operations of a spaceflight experiment to investigate plant tropisms. Advances in Space Research. 2009; 44(8): 879-886. DOI: 10.1016/l.asr.2009.06.007.
Growth of Arabidopsis seedlings in 60-mm Petri dishes in the dark as in the BRIC-LED system. Seedlings of the Columbia ecotype grown in nutrient agar (A) or on a series of membranes (B). The times indicate days after sowing the seeds in darkness.(courtesy of J.Z.Kiss)
+ View Larger Image
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).
+ View Larger Image
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.
+ View Larger Image
Seedlings of Arabidopsis thaliana grown in microgravity in the BRIC system on STS-131. Note the skewing of the root system.
+ View Larger Image