Limits...
The Arabidopsis minE mutation causes new plastid and FtsZ1 localization phenotypes in the leaf epidermis.

Fujiwara MT, Kojo KH, Kazama Y, Sasaki S, Abe T, Itoh RD - Front Plant Sci (2015)

Bottom Line: Plastids in the leaf epidermal cells of plants are regarded as immature chloroplasts that, like mesophyll chloroplasts, undergo binary fission.In atminE1, the size and shape of epidermal plastids varied widely, which contrasts with the plastid phenotype observed in atminE1 mesophyll cells.Observation of an atminE1 transgenic line harboring an AtMinE1 promoter::AtMinE1-yellow fluorescent protein fusion gene confirmed the expression and plastidic localization of AtMinE1 in the leaf epidermis.

View Article: PubMed Central - PubMed

Affiliation: RIKEN Nishina Center Saitama, Japan ; Graduate School of Science and Technology, Sophia University Tokyo, Japan.

ABSTRACT
Plastids in the leaf epidermal cells of plants are regarded as immature chloroplasts that, like mesophyll chloroplasts, undergo binary fission. While mesophyll chloroplasts have generally been used to study plastid division, recent studies have suggested the presence of tissue- or plastid type-dependent regulation of plastid division. Here, we report the detailed morphology of plastids and their stromules, and the intraplastidic localization of the chloroplast division-related protein AtFtsZ1-1, in the leaf epidermis of an Arabidopsis mutant that harbors a mutation in the chloroplast division site determinant gene AtMinE1. In atminE1, the size and shape of epidermal plastids varied widely, which contrasts with the plastid phenotype observed in atminE1 mesophyll cells. In particular, atminE1 epidermal plastids occasionally displayed grape-like morphology, a novel phenotype induced by a plastid division mutation. Observation of an atminE1 transgenic line harboring an AtMinE1 promoter::AtMinE1-yellow fluorescent protein fusion gene confirmed the expression and plastidic localization of AtMinE1 in the leaf epidermis. Further examination revealed that constriction of plastids and stromules mediated by the FtsZ1 ring contributed to the plastid pleomorphism in the atminE1 epidermis. These results illustrate that a single plastid division mutation can have dramatic consequences for epidermal plastid morphology, thereby implying that plastid division and morphogenesis are differentially regulated in epidermal and mesophyll plastids.

No MeSH data available.


Related in: MedlinePlus

Utility of cyan fluorescent protein (CFP) to investigate plastid morphology in Arabidopsis leaf epidermis. (A–C) A framework describing the replication and morphology of leaf mesophyll chloroplasts. Schematic diagram of chloroplast replication by binary fission (A) and chloroplast phenotypes in WT (B) and atminE1(C) leaf mesophyll cells are shown. (D) Detection of plastid-targeted green fluorescent protein (GFP, left) and CFP (right) in leaf epidermis. (E) Dual detection of plastid-targeted CFP and chlorophyll (Chl magenta-colored), mitochondria-targeted YFP (orange-colored) or FtsZ1–GFP (orange-colored) in leaf epidermis. (D,E) Leaves from 2-week-old seedlings of WT-background transgenic lines were observed by fluorescence microscopy. In merged images, CFP fluorescence is colored in cyan. Bars = 5 μm (black) and 10 μm (white).
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4593956&req=5

Figure 1: Utility of cyan fluorescent protein (CFP) to investigate plastid morphology in Arabidopsis leaf epidermis. (A–C) A framework describing the replication and morphology of leaf mesophyll chloroplasts. Schematic diagram of chloroplast replication by binary fission (A) and chloroplast phenotypes in WT (B) and atminE1(C) leaf mesophyll cells are shown. (D) Detection of plastid-targeted green fluorescent protein (GFP, left) and CFP (right) in leaf epidermis. (E) Dual detection of plastid-targeted CFP and chlorophyll (Chl magenta-colored), mitochondria-targeted YFP (orange-colored) or FtsZ1–GFP (orange-colored) in leaf epidermis. (D,E) Leaves from 2-week-old seedlings of WT-background transgenic lines were observed by fluorescence microscopy. In merged images, CFP fluorescence is colored in cyan. Bars = 5 μm (black) and 10 μm (white).

Mentions: Plastids are ancient prokaryote-derived organelles in plant cells that multiply via division of pre-existing organelles. The photosynthetic plastids, chloroplasts, undergo symmetric division, which produces a homogeneous population of spherical chloroplasts in each mature-leaf cell (Possingham and Lawrence, 1983; López-Juez and Pyke, 2005; Figures 1A,B). Chloroplast fissions are driven by a macromolecular complex located on the double-envelope membrane at the plastid constriction site. In the model plant Arabidopsis thaliana, approximately 10 nuclear-encoded proteins are located at distinct subplastidic compartments, which constitute the division apparatus (Yang et al., 2008; Okazaki et al., 2010). Among these proteins, the prokaryotic tubulin-like protein FtsZ, which stands for “Filamenting temperature-sensitive Z”, plays a central role in the initiation and progress of chloroplast division. A. thaliana has two phylogenetically distinct, functionally non-redundant FtsZ proteins, FtsZ1 and FtsZ2 (Stokes and Osteryoung, 2003; Miyagishima et al., 2004), both of which have polymerization and filament-bundling activities, enabling them to form a contractile ring structure at the mid-chloroplast site (McAndrew et al., 2001; Vitha et al., 2001; Yoder et al., 2007).


The Arabidopsis minE mutation causes new plastid and FtsZ1 localization phenotypes in the leaf epidermis.

Fujiwara MT, Kojo KH, Kazama Y, Sasaki S, Abe T, Itoh RD - Front Plant Sci (2015)

Utility of cyan fluorescent protein (CFP) to investigate plastid morphology in Arabidopsis leaf epidermis. (A–C) A framework describing the replication and morphology of leaf mesophyll chloroplasts. Schematic diagram of chloroplast replication by binary fission (A) and chloroplast phenotypes in WT (B) and atminE1(C) leaf mesophyll cells are shown. (D) Detection of plastid-targeted green fluorescent protein (GFP, left) and CFP (right) in leaf epidermis. (E) Dual detection of plastid-targeted CFP and chlorophyll (Chl magenta-colored), mitochondria-targeted YFP (orange-colored) or FtsZ1–GFP (orange-colored) in leaf epidermis. (D,E) Leaves from 2-week-old seedlings of WT-background transgenic lines were observed by fluorescence microscopy. In merged images, CFP fluorescence is colored in cyan. Bars = 5 μm (black) and 10 μm (white).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4593956&req=5

Figure 1: Utility of cyan fluorescent protein (CFP) to investigate plastid morphology in Arabidopsis leaf epidermis. (A–C) A framework describing the replication and morphology of leaf mesophyll chloroplasts. Schematic diagram of chloroplast replication by binary fission (A) and chloroplast phenotypes in WT (B) and atminE1(C) leaf mesophyll cells are shown. (D) Detection of plastid-targeted green fluorescent protein (GFP, left) and CFP (right) in leaf epidermis. (E) Dual detection of plastid-targeted CFP and chlorophyll (Chl magenta-colored), mitochondria-targeted YFP (orange-colored) or FtsZ1–GFP (orange-colored) in leaf epidermis. (D,E) Leaves from 2-week-old seedlings of WT-background transgenic lines were observed by fluorescence microscopy. In merged images, CFP fluorescence is colored in cyan. Bars = 5 μm (black) and 10 μm (white).
Mentions: Plastids are ancient prokaryote-derived organelles in plant cells that multiply via division of pre-existing organelles. The photosynthetic plastids, chloroplasts, undergo symmetric division, which produces a homogeneous population of spherical chloroplasts in each mature-leaf cell (Possingham and Lawrence, 1983; López-Juez and Pyke, 2005; Figures 1A,B). Chloroplast fissions are driven by a macromolecular complex located on the double-envelope membrane at the plastid constriction site. In the model plant Arabidopsis thaliana, approximately 10 nuclear-encoded proteins are located at distinct subplastidic compartments, which constitute the division apparatus (Yang et al., 2008; Okazaki et al., 2010). Among these proteins, the prokaryotic tubulin-like protein FtsZ, which stands for “Filamenting temperature-sensitive Z”, plays a central role in the initiation and progress of chloroplast division. A. thaliana has two phylogenetically distinct, functionally non-redundant FtsZ proteins, FtsZ1 and FtsZ2 (Stokes and Osteryoung, 2003; Miyagishima et al., 2004), both of which have polymerization and filament-bundling activities, enabling them to form a contractile ring structure at the mid-chloroplast site (McAndrew et al., 2001; Vitha et al., 2001; Yoder et al., 2007).

Bottom Line: Plastids in the leaf epidermal cells of plants are regarded as immature chloroplasts that, like mesophyll chloroplasts, undergo binary fission.In atminE1, the size and shape of epidermal plastids varied widely, which contrasts with the plastid phenotype observed in atminE1 mesophyll cells.Observation of an atminE1 transgenic line harboring an AtMinE1 promoter::AtMinE1-yellow fluorescent protein fusion gene confirmed the expression and plastidic localization of AtMinE1 in the leaf epidermis.

View Article: PubMed Central - PubMed

Affiliation: RIKEN Nishina Center Saitama, Japan ; Graduate School of Science and Technology, Sophia University Tokyo, Japan.

ABSTRACT
Plastids in the leaf epidermal cells of plants are regarded as immature chloroplasts that, like mesophyll chloroplasts, undergo binary fission. While mesophyll chloroplasts have generally been used to study plastid division, recent studies have suggested the presence of tissue- or plastid type-dependent regulation of plastid division. Here, we report the detailed morphology of plastids and their stromules, and the intraplastidic localization of the chloroplast division-related protein AtFtsZ1-1, in the leaf epidermis of an Arabidopsis mutant that harbors a mutation in the chloroplast division site determinant gene AtMinE1. In atminE1, the size and shape of epidermal plastids varied widely, which contrasts with the plastid phenotype observed in atminE1 mesophyll cells. In particular, atminE1 epidermal plastids occasionally displayed grape-like morphology, a novel phenotype induced by a plastid division mutation. Observation of an atminE1 transgenic line harboring an AtMinE1 promoter::AtMinE1-yellow fluorescent protein fusion gene confirmed the expression and plastidic localization of AtMinE1 in the leaf epidermis. Further examination revealed that constriction of plastids and stromules mediated by the FtsZ1 ring contributed to the plastid pleomorphism in the atminE1 epidermis. These results illustrate that a single plastid division mutation can have dramatic consequences for epidermal plastid morphology, thereby implying that plastid division and morphogenesis are differentially regulated in epidermal and mesophyll plastids.

No MeSH data available.


Related in: MedlinePlus