Space‐Based Research on Plant Tropisms

Correll, Melanie J.; Kiss, John Z.

doi:10.1002/9780470388297.ch8

Cited by 16 publications

(21 citation statements)

References 87 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…). Although gravity is the major stimulus that dictates the downward growth of a root, this process is influenced by a number of other environmental factors, such as water and nutrient availability, mechanical obstacles in the soil and light quality (Correll & Kiss ; Ponce et al . ; Monshausen & Gilroy ; Burbach et al .…”

Section: Introductionmentioning

confidence: 99%

The actin cytoskeleton is a suppressor of the endogenous skewing behaviour of Arabidopsis primary roots in microgravity

et al. 2013

View full text Add to dashboard Cite

Before plants can be effectively utilised as a component of enclosed life-support systems for space exploration, it is important to understand the molecular mechanisms by which they develop in microgravity. Using the Biological Research in Canisters (BRIC) hardware on board the second to the last flight of the Space Shuttle Discovery (STS-131 mission), we studied how microgravity impacts root growth in Arabidopsis thaliana. Ground-based studies showed that the actin cytoskeleton negatively regulates root gravity responses on Earth, leading us to hypothesise that actin might also be an important modulator of root growth behaviour in space. We investigated how microgravity impacted root growth of wild type (ecotype Columbia) and a mutant (act2-3) disrupted in a root-expressed vegetative actin isoform (ACTIN2). Roots of etiolated wild-type and act2-3 seedlings grown in space skewed vigorously toward the left, which was unexpected given the reduced directional cue provided by gravity. The left-handed directional root growth in space was more pronounced in act2-3 mutants than wild type. To quantify differences in root orientation of these two genotypes in space, we developed an algorithm where single root images were converted into binary images using computational edge detection methods. Binary images were processed with Fast Fourier Transformation (FFT), and histogram and entropy were used to determine spectral distribution, such that high entropy values corresponded to roots that deviated more strongly from linear orientation whereas low entropy values represented straight roots. We found that act2-3 roots had a statistically stronger skewing/coiling response than wild-type roots, but such differences were not apparent on Earth. Ultrastructural studies revealed that newly developed cell walls of space-grown act2-3 roots were more severely disrupted compared to space-grown wild type, and ground control wild-type and act2-3 roots. Collectively, our results provide evidence that, like root gravity responses on Earth, endogenous directional growth patterns of roots in microgravity are suppressed by the actin cytoskeleton. Modulation of root growth in space by actin could be facilitated in part through its impact on cell wall architecture.

show abstract

Section: Introductionmentioning

confidence: 99%

The actin cytoskeleton is a suppressor of the endogenous skewing behaviour of Arabidopsis primary roots in microgravity

et al. 2013

View full text Add to dashboard Cite

show abstract

“…In fact, experiments with plant seeds were part of the early Soviet and American space missions in the 1960s, and even on unmanned satellites in the late 1950s (Ferl & Paul ). There is also a wide range of literature on the effects of spaceflight on plants due to the many space projects related to plant biology (Halstead & Dutcher ; Correll & Kiss ).…”

Section: Introductionmentioning

confidence: 99%

Plant biology in reduced gravity on the Moon and Mars

Kiss

2013

Plant Biol J

View full text Add to dashboard Cite

While there have been numerous studies on the effects of microgravity on plant biology since the beginning of the Space Age, our knowledge of the effects of reduced gravity (less than the Earth nominal 1 g) on plant physiology and development is very limited. Since international space agencies have cited manned exploration of Moon/Mars as long-term goals, it is important to understand plant biology at the lunar (0.17 g) and Martian levels of gravity (0.38 g), as plants are likely to be part of bioregenerative life-support systems on these missions. First, the methods to obtain microgravity and reduced gravity such as drop towers, parabolic flights, sounding rockets and orbiting spacecraft are reviewed. Studies on gravitaxis and gravitropism in algae have suggested that the threshold level of gravity sensing is around 0.3 g or less. Recent experiments on the International Space Station (ISS) showed attenuation of phototropism in higher plants occurs at levels ranging from 0.l g to 0.3 g. Taken together, these studies suggest that the reduced gravity level on Mars of 0.38 g may be enough so that the gravity level per se would not be a major problem for plant development. Studies that have directly considered the impact of reduced gravity and microgravity on bioregenerative life-support systems have identified important biophysical changes in the reduced gravity environments that impact the design of these systems. The author suggests that the current ISS laboratory facilities with on-board centrifuges should be used as a test bed in which to explore the effects of reduced gravity on plant biology, including those factors that are directly related to developing life-support systems necessary for Moon and Mars exploration.

show abstract

“…Several studies have used the microgravity environment aboard orbiting spacecraft to identify downstream elements in signal transduction (reviewed in Correll and Kiss, 2008). An experiment with lentil roots was performed to identify the role of the actin cytoskeleton in amyloplast movement in microgravity (Driss-Ecole et al, 2000).…”

mentioning

confidence: 99%

An Endogenous Growth Pattern of Roots Is Revealed in Seedlings Grown in Microgravity

Millar

Johnson²,

Edelmann³

et al. 2011

Astrobiology

Self Cite

View full text Add to dashboard Cite

In plants, sensitive and selective mechanisms have evolved to perceive and respond to light and gravity. We investigated the effects of microgravity on the growth and development of Arabidopsis thaliana (ecotype Landsberg) in a spaceflight experiment. These studies were performed with the Biological Research in Canisters (BRIC) hardware system in the middeck region of the space shuttle during mission STS-131 in April 2010. Seedlings were grown on nutrient agar in Petri dishes in BRIC hardware under dark conditions and then fixed in flight with paraformaldehyde, glutaraldehyde, or RNAlater. Although the long-term objective was to study the role of the actin cytoskeleton in gravity perception, in this article we focus on the analysis of morphology of seedlings that developed in microgravity. While previous spaceflight studies noted deleterious morphological effects due to the accumulation of ethylene gas, no such effects were observed in seedlings grown with the BRIC system. Seed germination was 89% in the spaceflight experiment and 91% in the ground control, and seedlings grew equally well in both conditions. However, roots of space-grown seedlings exhibited a significant difference (compared to the ground controls) in overall growth patterns in that they skewed to one direction. In addition, a greater number of adventitious roots formed from the axis of the hypocotyls in the flight-grown plants. Our hypothesis is that an endogenous response in plants causes the roots to skew and that this default growth response is largely masked by the normal 1 g conditions on Earth.

show abstract

Space‐Based Research on Plant Tropisms

Cited by 16 publications

References 87 publications

The actin cytoskeleton is a suppressor of the endogenous skewing behaviour of Arabidopsis primary roots in microgravity

The actin cytoskeleton is a suppressor of the endogenous skewing behaviour of Arabidopsis primary roots in microgravity

Plant biology in reduced gravity on the Moon and Mars

An Endogenous Growth Pattern of Roots Is Revealed in Seedlings Grown in Microgravity

Contact Info

Product

Resources

About