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Analysis of a Novel Sensory Mechanism in Root Phototropism (Tropi)
01.27.10

Overview | Description | Applications | Operations | Results | Publications | Images

Experiment/Payload Overview

Brief Summary

Arabidopsis thaliana (thale cress) plants sprouted from seeds will be video taped and mature plants will be harvested. Later, the mature plants will be analyzed at the molecular level to determine what genes are responsible for successful plant growth in microgravity. Insights gained from Tropi can lead to sustainable agriculture for future long duration space missions.

Principal Investigator

  • John Kiss, Ph.D., Miami University, Oxford, OH

    • Co-Investigator(s)/Collaborator(s)

  • Richard Edelmann, Ph.D., Miami University, Oxford, OH
  • Roger Hangarter, Ph.D., Indiana University, Bloomington, IN
  • Melanie Correll, Ph.D., University of Florida, Gainesville, FL

    • Payload Developer

    Ames Research Center, Moffett Field, CA

    Sponsoring Agency

    National Aeronautics and Space Administration (NASA)

    Expeditions Assigned

    |14 |21/22 |23/24|

    Previous ISS Missions

    While Tropi is a new experiment, other studies of plant growth and development have been conducted on ISS.

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    Experiment/Payload Description

    Research Summary

    • Tropi is a plant growth experiment that will investigate how plant roots from Arabidopsis thaliana (thale cress) respond to varying levels of light and gravity.


    • Plant growth under various gravity conditions (0g to 1.0g) is achieved using a rotating centrifuge.


    • Plants grown will be analyzed to determine which genes are responsible for successful plant growth in microgravity.


    • This experiment will help gain insight into how plants grow in space to help create sustainable life support systems for long term space travel.

    Description

    Tropi consists of dry Arabidopsis thaliana (thale cress) seeds stored in small seed cassettes. Arabidopsis thaliana is a rapidly growing, flowering plant in the mustard family. The seed cassettes will be flown inside the European Modular Cultivation System (EMCS). The seeds will remain dry and at ambient temperature until hydrated by an automated system of the EMCS. At specified times during the experiment, the plants will be stimulated by different light spectrums and by different gravity gradients. The only work required by the crew is to replace video tapes and harvest the plants when they are grown. Once the plants are harvested they will be stored in the Minus Eighty Degree Laboratory Freezer for ISS Minus Eighty Degree Laboratory Freezer for ISS (MELFI) until their return to Earth. Part of the experiment relies on a biochemical analysis of the returned plants, but the investigators will gather a large amount of data from video taped images of the plants, watching their roots as they develop in the EMCS.

    The EMCS is an experiment facility for biological investigations under microgravity. It shall allow for cultivation, stimulation and crew assisted operation of biological experiments under well controlled conditions. Depending on the experiment specific hardware, it can be adapted to different applications e.g. to (larger) plants, invertebrates and in potential future configurations also for confocal microscopic observations or for aquatic species. EMCS is designed as a payload for the EXPRESS rack. It will be launched inside an EXPRESS transportation rack on a utilization flight. The EMCS facility will be transported to the dedicated EXPRESS rack in the US Lab on ISS. The resupply modules for gas and water will be exchanged in intervals of three months to one year. The EMCS experiments are composed Experiment Containers (EC) and Experiment Unique Equipment (EUE) which are inside the EC. The EC's are loaded manually by crew in the facility. Once the loading by the crew is completed, the experiments will be performed automatically inside the EMCS.

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    Applications

    Space Applications

    During long-term space exploration it will be necessary to provide astronauts 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.

    Earth Applications

    Further understanding of how plants grow and develop at a molecular level can lead to significant advancements in agricultural production on Earth.

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    Operations

    Operational Requirements

    During its ascent, Tropi requires no resources. The dry seeds are contained in five seed cassettes located in the EMCS. Once in orbit, the seeds will be hydrated automatically. Through the experiment, video will be taken allowing the ground team to evaluate and study the progress of development of the plants. Ninety percent of the science return is base on video analysis. The crew will harvest the plants and store the specimens in MELFI. They are also required to change out the video tapes.

    Operational Protocols

    Seed cassettes containing dried Arabidopsis thaliana seeds will be initiated in the EMCS automatically. The EMCS will introduce water to the seeds to activate growth. Video cameras will record the growth and development of the plants. Once the plants are grown, the crewmembers will harvest the plants and place them in the cold storage in MELFI. The plants will be returned to the ground team for further study.

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    Results/More Information

    Preliminary analysis of the Tropi samples returned on STS-116 in December 2006 resulted in little or no yield of total RNA as indicated by the lack of discrete bands shown on gel A (image 6). However, samples returned on STS-117 in June 2007 resulted in good quality RNA as indicated by the discrete bands shown on gel B (image 6). For the samples returned on STS-117, a 3-minute requirement was established, the seedlings in the Tropi cassettes would be transferred from MELFI to the JSC cold bag within 3 minutes on the ISS. This new requirement resulted in success of the cold transfer procedures and successful yield of RNA (John Kiss, "New Tropi Cold Procedures - Excellent RNA!" Email to Julie Robinson, ISS Program Scientist. 26 Nov. 2007).

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    Related Web Sites
  • The Arabidopsis Information Resource
  • University of Miami, Department of Botany

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    Publications

    Results Publications
    • Correll MJ, Edelmann RE, Hangarter RP, Mullen JL, Kiss JZ. Ground-based studies of tropisms in hardware developed for the European Modular Cultivation System (EMCS). Advances in Space Research. 2005 ;36:1203-1210.

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    Related Publications
    • Matia I, Gonzalez-Camacho F, Herraanx R, Kiss JZ, Gasset G, JWA van Loon J, Marco R, Medina FJ. Plant cell proliferation and growth are altered by microgravity conditions in spaceflight. Journal of Plant Physiology. ;167(3):184-193. 2009.
    • Kumar P, Montgomery CE, Kiss JZ. The role of pytochrome C in gravitropism and phototropism in Arabidopsis thaliana. Functional Plant Biology. ;35:298 - 305. 2008
    • 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. ;39:1154-1160 2007
    • Molas ML, Kiss JZ, Correll MJ. Gene profiling of the red light signalling pathways in roots. Journal of Experimental Botany. ;57(12):3217-3229. 2006
    • Mullen J L, Wolverton C, Hangarter R Apical control, gravitropic signaling, and the growth of lateral roots in Arabidopsis Advances in Space Research ;36:1211-1217. 2005
    • Correll MJ, Kiss JZ. The roles of phytochromes in elongation and gravitropism of roots. Plant and Cell Physiology. ;46:317-323. 2005

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    Images

    imageEMCS sample cartridge that will be spun in the EMCS centrifuge. Inset image is of Arabidopsis thaliana (thale cress) seedlings like the ones that will be used for Tropi. Tropi will compare the growth of root tips toward light in the absence of gravity, and allow the distinction between two redundant internal plant growth systems that respond to different colors of light. Image courtesy of NASA, Johnson Space Center.
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    imageScreenshot of Tropi during Expedition 14 shows several cassettes in an Experiment Containers (EC) and the growth of young Arabidopsis thaliana seedlings during the "growth phase". Image courtesy of NASA, Johnson Space Center.
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    imageScreenshot of Tropi at the beginning of "stimulation phase". This image will be used in analysis of tropisms. Image courtesy of NASA, Johnson Space Center.
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    imagePrinciple Investigator John Kiss, Ph.D., from Miami University, Oxford, OH, and Ann-Iren Kittang from the Norwegian University of Science and Technology, Trondheim Norway, sit at the control console at N-USOC (Norwegian User Support and Operations Centre) in Trondheim, Norway during the second run of the Tropi investigation.
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    imageNASA Image: ISS014E10652 - View of the TROPI seedling cassette for the European Modular Cultivation System (EMCS) - Experiment Container (EC) in the Destiny laboratory module during Expedition 14.
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    imageRNA gels of frozen plant samples from the Tropi investigation. Gel A shows samples returned in Decmeber 2006 did not yield any RNA. Gel B shows RNA in the samples returned in June 2007 following the establishment of cold transfer procedures. Image courtesy of Dr. John Kiss.
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    imageClose-up of Arabidopsis seedlings with seed cassette cover removed. Image courtesy of Ames Research Center, Moffett Field, CA.
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    imageDwarf Arabidopsis plant (left). Dwarf Arabidopsis plant (right). Image courtesy of Ames Research Center, Moffett Field, CA.
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    imageEuropean Modular Cultivation System (EMCS) Tropi experiment unique equipment (EUE) shown stimulating Arabidopsis seedlings with blue light (left). ENCS Tropi EUE shown stimulating Arabidopsis seedlings with red light (right). Image courtesy of Ames Research Center, Moffett Field, CA.
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    Information Provided and Updated by the ISS Program Scientist's Office
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