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Micrasterias as a Model System in Plant Cell Biology.

Lütz-Meindl U - Front Plant Sci (2016)

Bottom Line: The review focuses particularly on cell wall formation and composition, dictyosomal structure and function, cytoskeleton control of growth and morphogenesis as well as on ionic regulation and signal transduction.It has been also shown in the recent years that Micrasterias is a highly sensitive indicator for environmental stress impact such as heavy metals, high salinity, oxidative stress or starvation.This review is intended to summarize and discuss the most important results obtained in Micrasterias in the last 20 years and to compare the results to similar processes in higher plant cells.

View Article: PubMed Central - PubMed

Affiliation: Plant Physiology Division, Cell Biology Department, University of Salzburg Salzburg, Austria.

ABSTRACT
The unicellular freshwater alga Micrasterias denticulata is an exceptional organism due to its complex star-shaped, highly symmetric morphology and has thus attracted the interest of researchers for many decades. As a member of the Streptophyta, Micrasterias is not only genetically closely related to higher land plants but shares common features with them in many physiological and cell biological aspects. These facts, together with its considerable cell size of about 200 μm, its modest cultivation conditions and the uncomplicated accessibility particularly to any microscopic techniques, make Micrasterias a very well suited cell biological plant model system. The review focuses particularly on cell wall formation and composition, dictyosomal structure and function, cytoskeleton control of growth and morphogenesis as well as on ionic regulation and signal transduction. It has been also shown in the recent years that Micrasterias is a highly sensitive indicator for environmental stress impact such as heavy metals, high salinity, oxidative stress or starvation. Stress induced organelle degradation, autophagy, adaption and detoxification mechanisms have moved in the center of interest and have been investigated with modern microscopic techniques such as 3-D- and analytical electron microscopy as well as with biochemical, physiological and molecular approaches. This review is intended to summarize and discuss the most important results obtained in Micrasterias in the last 20 years and to compare the results to similar processes in higher plant cells.

No MeSH data available.


Related in: MedlinePlus

Immuno labeling of the cell wall of developing stages of Micrasterias. (A–E) Primary wall of different developing stages of Micrasterias labeled by polyclonal anti-xyloglucan antibody. Asterisks indicate growing semicells (scale bars are 50 μm). (F) Immunogold labeling of the non-growing secondary wall by BG1 antibody recognizing (1-3, 1-4)-ß-D-glucans. Mucilage (asterisk) in cell wall pore (P) and mucilage vesicle are not labeled (scale bar is 0.5 μm). Reprinted with permission from Eder et al. (2008), Copyright© 2008 Phycological Society of America.
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Figure 4: Immuno labeling of the cell wall of developing stages of Micrasterias. (A–E) Primary wall of different developing stages of Micrasterias labeled by polyclonal anti-xyloglucan antibody. Asterisks indicate growing semicells (scale bars are 50 μm). (F) Immunogold labeling of the non-growing secondary wall by BG1 antibody recognizing (1-3, 1-4)-ß-D-glucans. Mucilage (asterisk) in cell wall pore (P) and mucilage vesicle are not labeled (scale bar is 0.5 μm). Reprinted with permission from Eder et al. (2008), Copyright© 2008 Phycological Society of America.

Mentions: The growing primary wall of Micrasterias also contains xyloglucans (Eder et al., 2008) similar to those of higher land plants as indicated by fluorescence labeling (Figures 4A–E) by an antibody directed against higher plant epitopes (Lynch and Staehelin, 1992). Immuno TEM experiments showed that some of these epitopes are also present in the secondary wall. Binding of this antibody at the trans-side and in primary wall material containing vesicles (D-vesicles) suggests that these xyloglucans are secreted in Micrasterias similar to higher plant cells. Interestingly the secondary wall of Micrasterias (Figure 4F) but not the primary wall also contains mixed-linked glucans [(1-3, 1-4)-ß-D-glucans; Eder et al., 2008] that belong to the mayor polysaccharide component of the cell wall of grasses (Gibeaut and Carpita, 1993; Meikle et al., 1994; Trethewey et al., 2005). Similar glucans have also been identified in the alga Ulva lactuca and in the liverwort Lophocolea bidentata by (1-3, 1-4)-ß-D-glucanase digestion (Popper and Fry, 2003).


Micrasterias as a Model System in Plant Cell Biology.

Lütz-Meindl U - Front Plant Sci (2016)

Immuno labeling of the cell wall of developing stages of Micrasterias. (A–E) Primary wall of different developing stages of Micrasterias labeled by polyclonal anti-xyloglucan antibody. Asterisks indicate growing semicells (scale bars are 50 μm). (F) Immunogold labeling of the non-growing secondary wall by BG1 antibody recognizing (1-3, 1-4)-ß-D-glucans. Mucilage (asterisk) in cell wall pore (P) and mucilage vesicle are not labeled (scale bar is 0.5 μm). Reprinted with permission from Eder et al. (2008), Copyright© 2008 Phycological Society of America.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4940373&req=5

Figure 4: Immuno labeling of the cell wall of developing stages of Micrasterias. (A–E) Primary wall of different developing stages of Micrasterias labeled by polyclonal anti-xyloglucan antibody. Asterisks indicate growing semicells (scale bars are 50 μm). (F) Immunogold labeling of the non-growing secondary wall by BG1 antibody recognizing (1-3, 1-4)-ß-D-glucans. Mucilage (asterisk) in cell wall pore (P) and mucilage vesicle are not labeled (scale bar is 0.5 μm). Reprinted with permission from Eder et al. (2008), Copyright© 2008 Phycological Society of America.
Mentions: The growing primary wall of Micrasterias also contains xyloglucans (Eder et al., 2008) similar to those of higher land plants as indicated by fluorescence labeling (Figures 4A–E) by an antibody directed against higher plant epitopes (Lynch and Staehelin, 1992). Immuno TEM experiments showed that some of these epitopes are also present in the secondary wall. Binding of this antibody at the trans-side and in primary wall material containing vesicles (D-vesicles) suggests that these xyloglucans are secreted in Micrasterias similar to higher plant cells. Interestingly the secondary wall of Micrasterias (Figure 4F) but not the primary wall also contains mixed-linked glucans [(1-3, 1-4)-ß-D-glucans; Eder et al., 2008] that belong to the mayor polysaccharide component of the cell wall of grasses (Gibeaut and Carpita, 1993; Meikle et al., 1994; Trethewey et al., 2005). Similar glucans have also been identified in the alga Ulva lactuca and in the liverwort Lophocolea bidentata by (1-3, 1-4)-ß-D-glucanase digestion (Popper and Fry, 2003).

Bottom Line: The review focuses particularly on cell wall formation and composition, dictyosomal structure and function, cytoskeleton control of growth and morphogenesis as well as on ionic regulation and signal transduction.It has been also shown in the recent years that Micrasterias is a highly sensitive indicator for environmental stress impact such as heavy metals, high salinity, oxidative stress or starvation.This review is intended to summarize and discuss the most important results obtained in Micrasterias in the last 20 years and to compare the results to similar processes in higher plant cells.

View Article: PubMed Central - PubMed

Affiliation: Plant Physiology Division, Cell Biology Department, University of Salzburg Salzburg, Austria.

ABSTRACT
The unicellular freshwater alga Micrasterias denticulata is an exceptional organism due to its complex star-shaped, highly symmetric morphology and has thus attracted the interest of researchers for many decades. As a member of the Streptophyta, Micrasterias is not only genetically closely related to higher land plants but shares common features with them in many physiological and cell biological aspects. These facts, together with its considerable cell size of about 200 μm, its modest cultivation conditions and the uncomplicated accessibility particularly to any microscopic techniques, make Micrasterias a very well suited cell biological plant model system. The review focuses particularly on cell wall formation and composition, dictyosomal structure and function, cytoskeleton control of growth and morphogenesis as well as on ionic regulation and signal transduction. It has been also shown in the recent years that Micrasterias is a highly sensitive indicator for environmental stress impact such as heavy metals, high salinity, oxidative stress or starvation. Stress induced organelle degradation, autophagy, adaption and detoxification mechanisms have moved in the center of interest and have been investigated with modern microscopic techniques such as 3-D- and analytical electron microscopy as well as with biochemical, physiological and molecular approaches. This review is intended to summarize and discuss the most important results obtained in Micrasterias in the last 20 years and to compare the results to similar processes in higher plant cells.

No MeSH data available.


Related in: MedlinePlus