Nucleolar structure and proliferation activity of Arabidopsis root cells from seedlings germinated on the International Space Station

Seed Germination and Seedling Growth under Simulated Microgravity Causes Alterations in Plant Cell Proliferation and Ribosome Biogenesis

“…Similarly as described in the ISS experiment (Matía et al 2005), seedlings grown in simulated microgravity showed a longer span than those grown in control conditions (Fig. 1).…”

“…The analysis consisted of biometrical estimations of the seedling length, quantitative measurements at the cellular level, including number and size of root meristematic cells, in order to get an estimate of the cell proliferation rate, and morphometrical, ultrastructural and immunocytochemical study of the nucleolus, in order to know the rate of ribosome biogenesis. The results interestingly showed an enhanced rate of cell proliferation accompanied by a reduction of ribosome biogenesis per cell in samples grown in real microgravity, compared to ground 1 g controls; this strongly suggests that weightlessness is a serious stress for the plant cell, capable of uncoupling cell proliferation and ribosome biogenesis, two processes which, as previously indicated, are closely interrelated under ground physiological conditions (Matía et al 2005(Matía et al , 2007. This experiment was replicated, using the same hardware and conditions, in simulated microgravity, using a Random Positioning Machine (RPM).…”

Germination of Arabidopsis Seed in Space and in Simulated Microgravity: Alterations in Root Cell Growth and Proliferation

“…Consequently, the production of ribosomes, the protein factories of the cell, was reduced, as was cell growth (Bernstein and Baserga 2004;Baserga 2007). Thus, it was concluded that exposure to real microgravity produced alterations in cell proliferation and cell growth (Matía et al 2005(Matía et al , 2007.…”

“…Seedlings were fixed while in space, prior to post-flight structural and morphometric analyses of root meristematic cells, including studies of the nucleolus and quantitative immunocytochemical investigations of the expression of the nucleolar protein, nucleolin. Details of the experimental design, the hardware used and procedures have been published previously (Matía et al 2005(Matía et al , 2007.…”

Plant cell gravisensitivity and adaptation to microgravity

“…These results are totally consistent with data obtained from spaceflight experiments with A. thaliana , in which the reduction in nucleolar activity was related to alterations in cell proliferation (Matia et al . , ). Cell proliferation was also enhanced, but with reduced cell growth in A. thaliana root meristematic cells in both real and simulated microgravity (Manzano et al .…”