Search NASA⌕ Search

SEARCH · Search NASA

Results for “Plant Gravity”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 55 records · Page 3
All sourcesNASA NTRSDOE OSTI
NASA NTRS2021

SMD Technology Highlights

Two technology highlights from the Science Mission Directorate (SMD) Planetary Science Division and Biological and Physical Sciences division are featured: a) The Dynamic Radioisotope Power Systems Project (DRPS) may enable lunar science payloads to survive and thrive during the harsh lunar night. New robust DRPS have been built and delivered by industry and are in the process of being tested at NASA’s Glenn Research Center. b) NASA's Plant Water Management (PWM) project is demonstrating that even without the help of gravity, hydroponic plant watering methods can enable plant habitats aboard crewed or robotic space missions. On Earth, plants draw water upwards through the roots against gravity, via capillary action, which orients the plant and enables display of its canopy (foliage and branches) for optimal photosynthesis and transpiration. The plant grows above the nutrient-rich soil as the water U.S. Astronaut Kate Rubins poses with PWM after nearly doubling the science returns of the ISS experiment by drawing on her wealth of wet lab operations and handling experience—on Earth and in space.

RPS↗
NASA NTRS1981

Gravity, lignification, and land plant evolution

Vascular plants began their occupation of the wetlands interfacing both terrestrial and marine environments at some point in early Paleozoic time. Chemical differences between green algae and vascular land plants are mainly related to an abundance of lignins in the land plants. Answers to questions relating to the phylogeny and adaptive significance of the lignins must depend on experiments and observations using contemporary plant material. A summary is provided of a series of such observations. It is found that the differences between modern Chlorophyta and vascular land plants cannot be explained in full on the basis of lignification alone. Nevertheless, the data point to the emergence of the primitive land populations into an oxygen-rich terrestrial world where the need for mechanical support and water conservation could be met by a single aerobic biochemical process connected to essential aromatic amino acids likely to be found in every cell

Siegel, S. M.↗
NASA NTRS2003

Root phototropism: how light and gravity interact in shaping plant form

The interactions among tropisms can be critical in determining the final growth form of plants and plant organs. We have studied tropistic responses in roots as an example of these type of interactions. While gravitropism is the predominant tropistic response in roots, phototropism also plays a role in the oriented growth in this organ in flowering plants. In blue or white light, roots exhibit negative phototropism, but red light induces positive phototropism. In the flowering plant Arabidopsis, the photosensitive pigments phytochrome A (phyA) and phytochrome B (phyB) mediate this positive red-light-based photoresponse in roots since single mutants (and the double phyAB mutant) were severely impaired in this response. While blue-light-based negative phototropism is primarily mediated by the phototropin family of photoreceptors, the phyA and phyAB mutants (but not phyB) were inhibited in this response relative to the WT. The differences observed in phototropic responses were not due to growth limitations since the growth rates among all the mutants tested were not significantly different from that of the WT. Thus, our study shows that the blue-light and red-light systems interact in plants and that phytochrome plays a key role in integrating multiple environmental stimuli.

Non-NASA Center↗
NASA NTRS1985

NASA Space Biology Program: 9th Annual Symposium

Topics covered include plant and animal gravity receptors and transduction; the role of gravity in growth and development of plants and animals; biological support structures and the role of calcium; mechanisms and responses of gravity sensitive systems; and mechanisms of plant responses to gravity.

Thora W Halstead↗
NASA NTRSDate not supplied

The Light Microscopy Module A Facility Overview-History and Science

We will share a brief history and provide a science overview of the many accomplishments of the Light Microscopy Module (LMM), a microscope that has been operating in the microgravity environment of the International Space Station (ISS) since 2010. It will be removed in October 2021. It was initially outfitted for the Constrained Vapor Bubble – Wickless Heat Pipe experiment. It was later reconfigured and upgraded many times to support a broad portfolio of Physical science and Biological experiments including: Complex Fluids, Colloids, Macro-Molecular Biophysics, Protein Crystals, and Plant Biology. The LMM has enabled many significant studies and discoveries and has seen its fair share of pleasant surprises. These include recording order arising out of disorder, e.g., systems of colloids that were glasses on Earth crystallizing to form large defect-free crystals, nematic ordering of elliptical colloids, and colloidal-polymer systems crystallizing. The LMM science teams have also seen how to improve product stabilizers once the effects of sedimentation on Earth were removed; they were able to see which tagged genes express in plants when gravity is removed, telling them which genes are essential for growing plants in space; they’ve tested protein crystal growth models; checked models for creating bijel electrodes that turn batteries into fast-charging supercapacitors; tested many forms of colloidal self-assembly: including those using depletion attraction, magnetic fields, and critical Casimir forces; they’ve observed explosive bubble nucleation in a wickless heat pipe, and much more. This work has been supported by the NASA Biological and Physical Sciences (BPS) Division and the ISS Program Office, Johnson Space Center Code OZ and Code OB, the Center for the Advancement of Science in Space (CASIS) / ISS National Lab, EPSCoR, and ISS international partners from ESA – the Netherlands and Italy, CSA, JAXA and S. Korea, and by Space Act Agreements with Procter and Gamble (P&G).

Colloids↗
NASA NTRS1997

A down-to-earth model of gravisensing

The statolith hypothesis for gravity sensing is the most accepted model of gravity sensing in plants. However, the lukewarm acceptance of the statolith hypothesis among plant physiologists is most likely due to inertia and not due to any one experiment done over the past one hundred years that unambiguously pitted the statolith hypothesis against any of the competing hypotheses. Here we emphasize the weaknesses of the statolith hypothesis and suggest that the gravitational pressure hypothesis is superior in describing gravisensing in all plant cells.

Non-NASA Center↗
NASA NTRS1983

Gravitational effects on plant growth hormone concentration

Dolk's (1936) finding that more growth hormone diffuses from the lower side of a gravity-stimulated plant shoot than from the upper side is presently confirmed by means of both an isotope dilution assay and selected ion monitoring-gas chromatography-mass spectrometry, and it is established that the asymmetrically distributed hormone is indole-3-acetic acid (IAA). This is the first physicochemical demonstration that there is more IAA on the lower sides of a geostimulated plant shoot. It is also found that free IAA primarily occurs in the conductive vascular tissues of the shoot, while IAA esters predominate in the growing cortical cells. A highly sensitive gas chromatographic isotope dilution assay shows that the hormone asymmetry also occurs in the nonvascular tissue.

Bandurski, R. S.↗
NASA NTRS1986

How roots perceive and respond to gravity

Graviperception by plant roots is believed to occur via the sedimentation of amyloplasts in columella cells of the root cap. This physical stimulus results in an accumulation of calcium on the lower side of the cap, which in turn induces gravicurvature. In this paper we present a model for root gravitropism integrating gravity-induced changes in electrical potential, cytochemical localization of calcium in cells of gravistimulated roots, and the interdependence of calcium and auxin movement. Key features of the model are that 1) gravity-induced redistribution of calcium is an early event in the transduction mechanism, and 2) apoplastic movement of calcium through the root-cap mucilage may be an important component of the pathway for calcium movement.

Non-NASA Center↗
NASA NTRS1992

STS-42 Preflight Background Briefing Life Sciences (MSFC)

A panel of scientists give an overview of the experiments that are to take place on-board the STS-42 Discovery mission. Ronald J. White, International Microgravity Laboratory (IML) Program Scientist, gives a general description of why going into space with IML is so important. Robert Snyder, IML Mission Scientist, describes other aspects of the microgravity environment. Millard Reschke, Principal Investigator (PI) Microgravity Vestibular Investigation (MVI), explains what MVI is and the effects of space on the vestibular system. David Heathcote, PI for the Gravitational Plant Physiology Facility (GPPF), describes the GPPF's on-board experiment involving the effects of light and gravity on plants. Claude Brillouet, Program Scientist of the Biorack Facility, gives an overview of the Biorack equipment and experiment. Alan Mortimer, Chief Life Sciences for the Canadian Space Agency (CSA), describes the on-board experiments for the long- and short-term effects of microgravity on humans and biotechnology (cell separation techniques). The men then answer questions from the press and NASA centers.

Source record↗
NASA NTRS2003

Early Gravitropic Events in Roots of Arabidopsis: Ca(2+)H(+) Fluxes in the Columella Cells

Despite the wealth of information derived from physiological approaches, molecular mechanisms for sensing and responding to gravity in plants remain largely uncharacterized. Roots of higher plants offer many advantages for studying the sensing and responding phases. In roots, gravisensing occurs in specialized cells, the columella cells in which earlier studies have indicated an involvement of the cytoskeleton, Ca(2+), H(+) and auxin in processing the gravity signal. The overall goal of this project was to characterize gravity-stimulated Ca(2+) and H(+) fluxes in the columella cells of a model plant Arabidopsis thaliana and to define their regulation. For this work we used intact Arabidopsis roots.

Feldman, Lewis↗
NASA NTRSDate not supplied

Demonstration of Fluid Dynamics for Plant Growing Systems in Varied Gravity Environments Through Scaled Capillary Models

The development of reliable and bioregenerative crop growth production systems is vital for human exploration into deep space. As humans prepare for space travel beyond LEO, scientists need to find a way to provide reliable and adequate water delivery for all stages of the plant's life cycle. Past production systems struggled with this and often led to overwatering in the system. To better understand this issue, NASA's Plant Water Management (PWM) experiments were able to model fluid flow through granular substrates, specifically a clay-based material arcilite, in 0-G. The PWM study can help researchers to predict fluid flow through the systems, however their model only works for an arcilite based system and was unable to account for different stages of plant growth. For future missions, payload requirements to support crop production system will need to be limited, leading to the use of in situ resources. This project aims to validate the PWM experiments as well as incorporate various materials into the design for growth systems. To meet these objectives, a series of terrestrial experiments will be deployed to mimic all gravities. By modifying the material, fluid, and size of the test subjects, the effect of Earth's gravity can be minimized. This project will aid researchers in the design of future crop production systems for surface missions by creating a refined model that can be used at all stages of plant growth and utilize in situ resources.

Plant Biology↗
NASA NTRS1994

Physiological and genetic characterization of plant growth and gravitropism in LED light sources

Among the many problems of growing plants in completely controlled environments, such as those anticipated for the space station and the CELSS program, is the need to provide light that is both adequate for photosynthesis and of proper quality for normal growth and development. NASA scientists and engineers have recently become interested in the possibility of utilizing densely packed, solid state, light emitting diodes (LED's) as a source for this light. Unlike more conventional incandescent or electrical discharge lamps, these sources are highly monochromatic and lack energy in spectral regions thought to be important for normal plant development. In addition, a recent observation by NASA scientist has suggested that infra-red LED's, that are routinely used as photographic safelights for plants grown in darkness, may interact with the ability of plants to detect gravity. In order to establish how plants respond to light from these LED light sources we carried out a series of experiments with known pigment mutants of the model mustard plant, Arabidopsis thaliana, growing in either a gravity field or on a clinostat to simulate a micro-gravity environment. Results indicate that only red light from the 665 nm LED's disrupts the ability of normal wildtype seedlings to detect a gravity stimulus. There was no consistent effect found for the far-red (735 nm) LED's or either of the infrared (880 nm or 935 nm) LED sources but both showed some effect in one or more of the genotypes tested. Of these five members of the phytochrome multigene family in Arabidopsis, only the phytochrome B pigment mutant (hy3) lacked the ability to detect gravity under all conditions. There was no effect of either micro-gravity (clinostat) or the infra-red LED's on the light induced inhibition of hypocotyl elongation. Measurements of the pigment phytochrome in oats also showed no photoconversion by 15 min irradiations with the infra-red LED's. We conclude that phytochrome B is required for the perception of gravity and that only red light is able to disrupt this perception. The infra-red LED's also do not appear to interact with gravity perception in Arabidopsis, but caution should be exercised if infra-red LED's are to be used as photographic safelights for these types of experiments.

Deitzer, Gerald F.↗
NASA NTRSDate not supplied

Demonstration of Fluid Dynamics for Plant Growing Systems in Varied Gravity Environments Through Scaled Capillary Models

A key aspect to the success of human health and performance is having a reliable and nutritious food supply. Dating back to the early days of human exploration, food was often one of the determining factors of whether a mission was successful. As humans begin to explore space, keeping astronauts well-nourished and satisfied through their meals will ensure that they are able to conduct research and push the bounds of the human presence of our universe. Currently, food supplies for shorter mission durations rely solely on pre-packaged foods and resupplies. While reliance on this type of food delivery is not an issue for short human space missions to Low Earth Orbit (LEO), once humans begin long-term missions to explore the lunar surface and beyond, a more sustainable and self-reliant food supply will be needed.

Capillary↗
NASA NTRS1978

Is gravity a morphological determinant in plants at the cellular level

The present paper deals with the question whether plant development can proceed normally in the weightless state, particularly in the critical stage where single cells produce multicellular units, leading to embryos with the growing regions of shoot and root which, in turn, give rise to all the tissues of the plant body. An experiment that tested whether carrot embryos capable of developing from cultured somatic cells could do so under conditions of weightlessness is described.

Krikorian, A. D.↗
NASA NTRS1985

Polyamines as Possible Modulators of Gravity-induced Calcium Transport in Plants

Data from various laboratories indicate a probable relationship between calcium movement and some aspects of graviperception and tropistic bending responses. The movement of calcium in response to gravistimulation appears to be rapid, polar and opposite in direction to polar auxin transport. What might be the cause of such rapid Ca(2+) movement? Data from studies on polyamine (PA) metabolism may furnish a clue. A transient increase in the activity of ornithine decarboxylase (ODC) and titers of various PAs occurs within 60 seconds after hormonal stimulation of animal cells, followed by Ca(2+) transport out of the cells. Through the use of specific inhibitors, it was shown that the enhanced PA synthesis from ODC was essential not only for Ca(2+) transport, but also for Ca(2+) transport-dependent endocytosis and the movement of hexoses and amino acids across the plasmalemma. In plants, rapid changes in arginine decarboxylase (ADC) activity occur in response to various plant stresses. Physical stresses associated with gravisensor displacement and reorientation of a plant in the gravitational field could similarly activate ADC and that resultant increases in PA levels might initiate transient perturbations in Ca(2+) homeostasis.

Galston, A. W.↗
NASA NTRS1994

Life Sciences and Space Research 25 (1). Gravitational Biology; Interdisciplinary Scientific Commission F of the COSPAR Plenary Meeting, 29th, Washington, DC, Aug. 28-Sep. 5, 1992

The conference includes papers describing theories and models of cell biology in microgravity and weightlessness; experimental research on cellular responses to altered gravity in plants and animals, natural and simulated; graviresponses in plants; gravitational effects in developmental biology; mechanisms of gravisensing; effects on animals and humans; and educational programs in Space Life Sciences.

Cogoli, A.↗
NASA NTRS1997

Three-Dimensional Analysis of Nuclear Size, Shape and Displacement in Clover Root Cap Statocytes from Space and a Clinostat

Under normal (l-g) conditions the statocytes of root caps have a characteristic polarity with the nucleus in tight association with the proximal cell wall; but, in altered gravity environments including microgravity (mu-g) and the clinostat (c-g) movement of the nucleus away from the proximal cell wall is not uncommon. To further understand the cause of gravity-dependent nuclear displacement in statocytes, three-dimensional cell reconstruction techniques were used to precisely measure the volumes, shapes, and positions of nuclei in white clover (Trifolium repens) flown in space and rotated on a clinostat. Seeds were germinated and grown for 72 hours aboard the Space Shuttle (STS-63) in the Fluid Processing Apparatus (BioServe Space Technologies, Univ. of Colorado, Boulder). Clinorotation experiments were performed on a two-axis clinostat (BioServe). Computer reconstruction of selected groups of statocytes were made from serial sections (0.5 microns thick) using the ROSS (Reconstruction Of Serial Sections) software package (Biocomputation Center, NASA Ames Research Center). Nuclei were significantly displaced from the tops of cells in mu-g (4.2 +/- 1.0 microns) and c-g (4.9 +/- 1.4 microns) when compared to l-g controls (3.4 +/- 0.8 gm); but, nuclear volume (113 +/- 36 cu microns, 127 +/- 32 cu microns and 125 +/- 28 cu microns for l-g, mu-g and c-g respectively) and the ratio of nuclear volume to cell volume (4.310.7%, 4.211.0% and 4.911.4% respectively) were not significantly dependent on gravity treatment (ANOVA; alpha = 0.05). Three-dimensional analysis of nuclear shape and proximity to the cell wall, however, showed that nuclei from l-g controls appeared ellipsoidal while those from space and the clinostat were more spherically shaped. This change in nuclear shape may be responsible for its displacement under altered gravity conditions. Since the cytoskeleton is known to affect nuclear polarity in root cap statocytes, those same cytoskeletal elements could also control nuclear shape. This alteration in nuclear shape and position in mu-g and c-g when compared to l-g may lead to functional differences in the gravity signaling systems of plants subjected to altered gravity environments.

Smith, J.D.↗