Differenciation et proliferation cellulaires dans des racines de mais cultive en microgravite (Biocosmos 1985)

Darbelley, Nicole; Driss‐Ecole, D.; Perbal, Gérald

doi:10.1016/0273-1177(86)90080-3

Cited by 8 publications

(4 citation statements)

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“…The overall root system morphology has been shown to change in microgravity, with diminished root growth resulting from primary root inhibition (Darbelley et al, 1986;Grif et al, 1988;Levine and Krikorian, 1992) and from the reduction in mitotic cell division (Krikorian and O'Connor, 1984;Slocum et al, 1984;Levine et al, 1990;Krikorian and Levine, 1992;Laurinavicius et al, 1994). Because past research showed that roots are shorter and thicker under oxygen-limited conditions (Unger and Danielson, 1965;Waddington and Baker, 1965), these morphological differences may be related to reduced levels of oxygen.…”

Section: Discussionmentioning

confidence: 99%

Spaceflight Exposure Effects on Transcription, Activity, and Localization of Alcohol Dehydrogenase in the Roots of Arabidopsis thaliana

et al. 1997

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Although considerable research and speculation have been directed toward understanding a plant's perception of gravity and the resulting gravitropic responses, little is known about the role of gravity-dependent physical processes in normal physiological function. These studies were conducted to determine whether the roots of plants exposed to spaceflight conditions may be experiencing hypoxia. Arabidopsis fhaliana (1.) Heynh. plants were grown in agar medium during 6 The increase in ADH activity associated with the spaceflight roots was realized by a 28% decrease in oxygen availability in a groundbased study; however, no reduction in redox potential was observed in measurements of the spaceflight bulk agar. Spaceflight exposure appears to effect a hypoxic response in the roots of agar-grown plants that may be caused by changes in gravity-mediated fluid and/or gas behavior.

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Section: Discussionmentioning

confidence: 99%

Spaceflight Exposure Effects on Transcription, Activity, and Localization of Alcohol Dehydrogenase in the Roots of Arabidopsis thaliana

et al. 1997

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“…In relation to this, an effect of microgravity, either real or simulated, on the proliferation rate of root meristematic cells was previously described. Mitotic index was the parameter reported to change in early pioneering studies on Plant Space Biology using lentil seedlings grown in microgravity, but the results of different experiments were not coincident (Darbelley et al, 1986, Driss-École et al, 1994.…”

Section: Simulated Microgravity Affects Meristematic Competencementioning

confidence: 99%

Functional alterations of root meristematic cells of Arabidopsis thaliana induced by a simulated microgravity environment

Boucheron-Dubuisson

Manzano

Disquet

et al. 2016

Journal of Plant Physiology

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Environmental gravity modulates plant growth and development, and these processes are influenced by the balance between cell proliferation and differentiation in meristems. Meristematic cells are characterized by the coordination between cell proliferation and cell growth, that is, by the accurate regulation of cell cycle progression and the optimal production of biomass for the viability of daughter cells after division. Thus, cell growth is correlated with the rate of ribosome biogenesis and protein synthesis. We investigated the effects of simulated microgravity on cellular functions of the root meristem in a sequential study. Seedlings were grown in a clinostat, a device producing simulated microgravity, for periods between 3 and 10days. In a complementary study, seedlings were grown in a Random Positioning Machine (RPM) and sampled sequentially after similar periods of growth. Under these conditions, the cell proliferation rate and the regulation of cell cycle progression showed significant alterations, accompanied by a reduction of cell growth. However, the overall size of the root meristem did not change. Analysis of cell cycle phases by flow cytometry showed changes in their proportion and duration, and the expression of the cyclin B1 gene, a marker of entry in mitosis, was decreased, indicating altered cell cycle regulation. With respect to cell growth, the rate of ribosome biogenesis was reduced under simulated microgravity, as shown by morphological and morphometric nucleolar changes and variations in the levels of the nucleolar protein nucleolin. Furthermore, in a nucleolin mutant characterized by disorganized nucleolar structure, the microgravity treatment intensified disorganization. These results show that, regardless of the simulated microgravity device used, a great disruption of meristematic competence was the first response to the environmental alteration detected at early developmental stages. However, longer periods of exposure to simulated microgravity do not produce an intensification of the cellular damages or a detectable developmental alteration in seedlings analyzed at further stages of their growth. This suggests that the secondary response to the gravity alteration is a process of adaptation, whose mechanism is still unknown, which eventually results in viable adult plants.

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“…Most of these experiments were focused on the cell cycle regulation (see . Early pioneering studies on spaceflight, using lentils as model species, reported changes in mitotic index of roots grown in microgravity (Darbelley et al 1986;Driss-École et al 1994). From data on this parameter it was difficult to draw firm conclusions on the factors and mechanisms affected, but it clearly pointed out that alterations of cell cycle caused by the space environment may occur.…”

Section: A Effects Of Microgravity On the Cell Cyclementioning

confidence: 99%

Plants in Space: Novel Physiological Challenges and Adaptation Mechanisms

et al. 2021

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Any space exploration initiative, such as the human presence in the Moon and Mars, must incorporate plants for life support. To enable space plant culture we need to understand how plants respond to extraterrestrial conditions, adapt to them and compensate their deleterious effects at multiple levels. Gravity is a major difference between the terrestrial and the extraterrestrial environment. Gravitropism is the process of establishing a growth direction for plant organs according to the gravity vector. Gravity signals are sensed at specialized tissues by the motion of amyloplasts called statoliths and transduced to produce a cellular polarization capable of influencing the transport of auxin. Gravity alterations eventually result in changes in the lateral balance of auxin in the root, producing deviations of the growth direction. Under microgravity, auxin changes affect the root meristem causing increased cell proliferation and decreased cell growth. The nucleolus, the nuclear site of production of ribosomes, is a marker of this unbalance, which could alter plant development. At the molecular level, microgravity induces a reprogramming of gene expression that mostly affects plant defense systems against abiotic stresses, indicating that these categories of genes are involved in the adaptation to extraterrestrial habitats. Nevertheless, no specific genes for plant response to gravitational stress have been identified. Despite this stress, plants survive, developing until the adult stage and reproducing under microgravity conditions. A major research challenge is to identify environmental factors, such as light, which could interact, modulate or balance the impact of gravity, contributing to the tolerance and survival of plants under spaceflight conditions. Understanding the crosstalk between light and gravity sensing will contribute to the success of the next generation agriculture in human settlements outside the Earth. Plants are needed for space exploration: Space Plant Biology."Je ne sais pas si les mondes sont habités, et, comme je ne le sais pas, je vais y voir!" ("I do not know if the worlds are inhabited, and, as I do not know that, I'll go there and see!") -Jules Verne, "From the Earth to the Moon" (1867).This quote, from one of the most famous books by Jules Verne, which was written more than a century and a half ago, reflects an intense human dream, which, at the same time is a major challenge for the humankind: to go out of our planet Earth and see how are "the other worlds", in particular, whether we, as living beings and, especially, as intelligent living beings, are alone in the Universe, or we have companions with whom we can interact. Science-fiction literature is full of stories talking about the relationships between humans and aliens, whether they are peaceful or hostile.In 2019, the entire world has commemorated the 50 th anniversary of the first human footprint on the surface of the Moon, and in 2020, the twenty years of the continuous presence of humans as crew members of the International S...

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Differenciation et proliferation cellulaires dans des racines de mais cultive en microgravite (Biocosmos 1985)

Cited by 8 publications

References 4 publications

Spaceflight Exposure Effects on Transcription, Activity, and Localization of Alcohol Dehydrogenase in the Roots of Arabidopsis thaliana

Spaceflight Exposure Effects on Transcription, Activity, and Localization of Alcohol Dehydrogenase in the Roots of Arabidopsis thaliana

Functional alterations of root meristematic cells of Arabidopsis thaliana induced by a simulated microgravity environment

Plants in Space: Novel Physiological Challenges and Adaptation Mechanisms

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