Advanced Plant Experiment - Canadian Space Agency 2 (APEX-CSA2) - 08.20.14
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The Advanced Plant Experiment - Canadian Space Agency 2 (APEX-CSA2) investigation examines white spruce, picea glauca, to understand the influence of gravity on plant physiology, growth, and on the genetics of wood formation. It utilizes the Advanced Biological Research System (ABRS) and is the second Canadian botany study to be conducted aboard the International Space Station (ISS).
Science Results for Everyone
Genes get spruce-d up in space. Researchers investigated the effect of gravity on white spruce tree genes aboard the space station and on Earth by growing seedlings in incubators that controlled light, temperature, humidity, and CO2 conditions. Examination of the spruce RNA showed that three genes had a statistically significant increase in expression under microgravity conditions. These three genes play a role in crucial processes such as cell reproduction and response to stress, and their increased expression likely influences seedling growth patterns in microgravity.
Bionetics Corporation, Cape Canaveral, FL, United States
Sponsoring Space Agency
Canadian Space Agency (CSA)
ISS Expedition Duration
March 2010 - September 2010
Previous ISS Missions
Expedition 22/23 is the first mission for the APEX-CSA2 investigation, which follows a similar experiment using the ABRS during Increment 21/22.
- The Advanced Plant Experiment - Canadian Space Agency 2 (APEX-CSA2) provides insight into the fundamental processes by which plants produce cellulose and lignin, the two main structural materials found in plant matter. The experiment will be conducted using Canadian white spruce, Picea glauca.
- On Earth, various portions of a plant can have physically different compositions including different ratios of lignin and cellulose. This will affect the sensitivity of the plants to environmental conditions, to disease and infection and will have an influence on the type of industrial application plants can be used for. It is expected that growth of the trees for 30 days in microgravity will affect their growth rate, composition, tissue organization and gene expression.
- The results of this experiment will include improvement of the technology to grow trees in a spacecraft, enhancement of our understanding of tree physiology in the space environment and identification of genes related to specific plant characteristics. It is expected that these genes can be used as markers for plant selection in various Earth applications and to improve sustainability of the forest.
Advanced Plant Experiment - Canadian Space Agency 2 (APEX-CSA2) will compare the genes and tissue of the white spruce, picea glauca, in microgravity and on Earth. Studying the genetics of plant growth on the International Space Station (ISS) can also lead to biotechnology applications in the field of forestry and agriculture. One of the challenges facing the forestry sector is balancing the increasing demand for wood fiber with the need to manage forest ecosystems in a sustainable way for present and future generations. By better understanding the genetics of white spruce, an economically important species widely used in the pulp and paper industry, it may one day be possible to select and design genetically improved varieties that would allow them to cope with climate change. Following the growth out some of the samples were preserved in formaldehyde to study tissue development (specifically, how the absence of gravity affects tissue composition, organization, plant growth and wood formation). Other samples were preserved for genetic analysis using a DNA chip known as a microarray, which was recently developed at Laval University in the context of the Arborea project. The microarray technique will allow scientists to determine how the trees’ genes were affected in microgravity.
APEX-CSA2 along with the ABRS hardware demonstrates the capabilities of providing the correct environment for plant growth onboard spacecraft. For future long-duration exploration, crews will need to be able to grow plants for a variety of applications.
Understanding the fundamental processes by which plants produce cellulose and lignin in their tissues is of great interest in the realm of forestry and industry. Trees used for paper production are selected for maximum cellulose production and minimal lignin production. Conversely, trees used to make structural lumber are selected for maximum lignin content. However, due to the complex relationship of these two biosynthesis processes, researchers do not yet know how to genetically alter such plants to further boost their productivity.
APEX-CSA2 requires a controlled environment provided by the ABRS facility which also provides images that are downlinked to the ground teams. The crew is responsible for planting, harvesting, reinitialization, water refill, and changing out the air filter. After harvesting, parts of the samples are chemically preserved and stored in the Minus Eighty-Degree Laboratory Freezer for ISS (MELFI).
The crew is responsible for performing the introduction of treelings in ABRS on flight day 3 and take photos of the root tray containing plants. Researchers on the ground monitored their growth using video cameras, and ISScrewmembers were asked to water the plants as necessary. Control plants were also grown in similar conditions at NASA’s Kennedy Space Center for comparison with the space-faring samples. After the 30-day growth period the plants are harvested by cutting parts of the stem and roots. These samples are then placed into KSC fixation tubes (KFTs) containing chemical preservatives and stored at ambient conditions or frozen in MELFI. To maintain the environment in the ABRS the crew uses a syringe to transfer approximately 60-mL of water from the ISS potable water source to each of two quick disconnect fittings associated with the two reservoirs inside the ABRS. Air filter change out is performed by opening the front hatch of the ABRS locker, loosening a restraining strap, and pulling each of the two filters off of the back side of the hatch.
Beaulieu J, Giguere I, Deslauriers M, Boyle B, MacKay J. Differential gene expression patterns in white spruce newly formed tissue on board the International Space Station. Advances in Space Research. 2013 August; 52(4): 760-772.
Ground Based Results Publications
Advanced Plant Experiment - CSA2 Backgrounder
Canadian Space Agency - Sprucing up in Space: APEX-CSA2 Uses the International Space Station to help Canada's Forestry Industry
NASA Image: ISS023E036876 - NASA astronaut T.J. Creamer, Expedition 23 flight engineer, services the Advanced Plant Experiments - CSA2 (APEX-CSA2) experiment in the Destiny laboratory of the International Space Station.
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NASA Image: ISS023E027445 - White spruce trees produced new shoots (pale green) during the 30-day growth within ABRS during ISS Expedition 23/24.
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NASA Image: ISS023E036880 - APEX-CSA2, white spruce tree samples collected by T.J. Creamer at the end of the 30-day grow-out during ISS Expedition 23/24.
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