TY - JOUR
T1 - Functional alterations of root meristematic cells of Arabidopsis thaliana induced by a simulated microgravity environment
T2 - Journal of Plant Physiology
AU - Boucheron-Dubuisson, E.
AU - Manzano, A.I.
AU - Le Disquet, I.
AU - Matia, I.
AU - Sáez-Vasquez, J.
AU - van Loon, J.J.W.A.
AU - Herranz, R.
AU - Carnero-Diaz, E.
AU - Medina, F.J.
AU - Bouchern-Dubuisson, E.
N1 - ISI Document Delivery No.: EE4SX Times Cited: 0 Cited Reference Count: 58 Bouchern-Dubuisson, Elodie Manzano, Ana I. Le Disquet, Isabel Matia, Isabel Saez-Vasquez, Julio van Loon, Jack J. W. A. Herranz, Raul Carnero-Diaz, Eugenie Medina, F. Javier Medina, F. Javier/0000-0002-0866-7710 Spanish "Plan Estatal de Investigacion Cientifica y Tenica y de Innovacion" of the Ministry of Economy and Competitiveness [AYA2012-33982, ESP2015-64323-R]; ERDF; French "Centre National d'Etudes Spatiales" (CNES); Dutch Space Research Organization (NWO-ALW-SRON) [MG-057] The skillful technical assistance of Mrs. Mercedes Carnota (CIB-CSIC), of the "Groupement Scientifique en Biologie et Medecine Spatiales" (GSBMS) (V. Pereda Loth and B. Eche, Universite Paul Sabatier, Toulouse) and of Mr. A. Dowson, from ESA-ESTEC, is gratefully acknowledged. We also thank G. Belleau (UPMC) for her help. This work was supported by the Spanish "Plan Estatal de Investigacion Cientifica y Tenica y de Innovacion" of the Ministry of Economy and Competitiveness [Grant numbers AYA2012-33982 and ESP2015-64323-R, co-funded by ERDF, and pre-doctoral fellowships to [A. I. M.] and [I. M.] (Program FPI)], the French "Centre National d'Etudes Spatiales" (CNES) (G. Gauquelin-Koch) and the Dutch Space Research Organization (NWO-ALW-SRON) [Grant number MG-057]. 0 16 ELSEVIER GMBH, URBAN & FISCHER VERLAG JENA J PLANT PHYSIOL
PY - 2016/12/1
Y1 - 2016/12/1
N2 - 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 10 days. 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.
AB - 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 10 days. 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.
U2 - https://doi.org/10.1016/j.jplph.2016.09.011
DO - https://doi.org/10.1016/j.jplph.2016.09.011
M3 - Article
C2 - 27792899
SN - 0176-1617
VL - 207
SP - 30
EP - 41
JO - Journal of Plant Physiology
JF - Journal of Plant Physiology
ER -