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Arabidopsis AtPLC2 Is a Primary Phosphoinositide-Specific Phospholipase C in Phosphoinositide Metabolism and the Endoplasmic Reticulum Stress Response.

Kanehara K, Yu CY, Cho Y, Cheong WF, Torta F, Shui G, Wenk MR, Nakamura Y - PLoS Genet. (2015)

Bottom Line: The seedlings of plc2-1 mutant showed growth defect that was complemented by heterologous expression of AtPLC2, suggesting that phosphoinositide-specific phospholipase C activity borne by AtPLC2 is required for seedling growth.Moreover, the plc2-1 mutant showed hypersensitive response to ER stress as evidenced by changes in relevant phenotypes and gene expression profiles.Our results revealed the primary enzyme in phosphoinositide metabolism, its involvement in seedling growth and an emerging link between phosphoinositide and the ER stress response.

View Article: PubMed Central - PubMed

Affiliation: Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan; Molecular and Biological Agricultural Sciences Program, Taiwan International Graduate Program, Academia Sinica, Taipei, Taiwan; Graduate Institute of Biotechnology and Department of Life Sciences, National Chung-Hsing University, Taichung, Taiwan; Muroran Institute of Technology, Muroran, Japan.

ABSTRACT
Phosphoinositides represent important lipid signals in the plant development and stress response. However, multiple isoforms of the phosphoinositide biosynthetic genes hamper our understanding of the pivotal enzymes in each step of the pathway as well as their roles in plant growth and development. Here, we report that phosphoinositide-specific phospholipase C2 (AtPLC2) is the primary phospholipase in phosphoinositide metabolism and is involved in seedling growth and the endoplasmic reticulum (ER) stress responses in Arabidopsis thaliana. Lipidomic profiling of multiple plc mutants showed that the plc2-1 mutant increased levels of its substrates phosphatidylinositol 4-phosphate and phosphatidylinositol 4,5-bisphosphate, suggesting that the major phosphoinositide metabolic pathway is impaired. AtPLC2 displayed a distinct tissue expression pattern and localized at the plasma membrane in different cell types, where phosphoinositide signaling occurs. The seedlings of plc2-1 mutant showed growth defect that was complemented by heterologous expression of AtPLC2, suggesting that phosphoinositide-specific phospholipase C activity borne by AtPLC2 is required for seedling growth. Moreover, the plc2-1 mutant showed hypersensitive response to ER stress as evidenced by changes in relevant phenotypes and gene expression profiles. Our results revealed the primary enzyme in phosphoinositide metabolism, its involvement in seedling growth and an emerging link between phosphoinositide and the ER stress response.

No MeSH data available.


Subcellular localization of fluorescent AtPLC2-Venus in 12-day-old seedlings of ProPLC2:PLC2-Venus transgenic plants.(A-D) Fluorescence of ProPLC2:PLC2-Venus (A) and staining of plasma membranes by FM4-64 dye (B) were merged (C) at stem epidermis. (E-H) Fluorescence of ProPLC2:PLC2-Venus (E) and staining of plasma membranes by FM4-64 dye (F) were merged (G) at leaf pavement and guard cells. (I-L) Fluorescence of ProPLC2:PLC2-Venus (I) and staining of plasma membranes by FM4-64 dye (J) were merged (K) at leaf mesophyll cells. (D), (H), and (L) are differential interference contrast (DIC) images for each sample. (M-P) Fluorescence of ProPLC2:PLC2-Venus (M), staining of nuclei by DAPI (N) and chlorophyll autofluorescence (O) were merged (P) at leaf mesophyll cells. Scale bars are 10 μm.
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pgen.1005511.g005: Subcellular localization of fluorescent AtPLC2-Venus in 12-day-old seedlings of ProPLC2:PLC2-Venus transgenic plants.(A-D) Fluorescence of ProPLC2:PLC2-Venus (A) and staining of plasma membranes by FM4-64 dye (B) were merged (C) at stem epidermis. (E-H) Fluorescence of ProPLC2:PLC2-Venus (E) and staining of plasma membranes by FM4-64 dye (F) were merged (G) at leaf pavement and guard cells. (I-L) Fluorescence of ProPLC2:PLC2-Venus (I) and staining of plasma membranes by FM4-64 dye (J) were merged (K) at leaf mesophyll cells. (D), (H), and (L) are differential interference contrast (DIC) images for each sample. (M-P) Fluorescence of ProPLC2:PLC2-Venus (M), staining of nuclei by DAPI (N) and chlorophyll autofluorescence (O) were merged (P) at leaf mesophyll cells. Scale bars are 10 μm.

Mentions: To further study the subcellular localization of AtPLC2 in different tissues, we observed stem epidermal cells (Fig 5A–5D), leaf epidermal cells (Fig 5E–5H), and mesophyll cells (Fig 5I–5L). In all cells observed here, the Venus signals were co-localized with the plasma membrane marker FM4-64 but not with the nuclear marker 4’,6’-diamino-2’-phenylindole (DAPI) or autofluorescence of chloroplasts (Fig 5M–5P). In addition to supporting the previous study [28], these observations suggest that AtPLC2 localizes mainly at the plasma membrane in different cell types.


Arabidopsis AtPLC2 Is a Primary Phosphoinositide-Specific Phospholipase C in Phosphoinositide Metabolism and the Endoplasmic Reticulum Stress Response.

Kanehara K, Yu CY, Cho Y, Cheong WF, Torta F, Shui G, Wenk MR, Nakamura Y - PLoS Genet. (2015)

Subcellular localization of fluorescent AtPLC2-Venus in 12-day-old seedlings of ProPLC2:PLC2-Venus transgenic plants.(A-D) Fluorescence of ProPLC2:PLC2-Venus (A) and staining of plasma membranes by FM4-64 dye (B) were merged (C) at stem epidermis. (E-H) Fluorescence of ProPLC2:PLC2-Venus (E) and staining of plasma membranes by FM4-64 dye (F) were merged (G) at leaf pavement and guard cells. (I-L) Fluorescence of ProPLC2:PLC2-Venus (I) and staining of plasma membranes by FM4-64 dye (J) were merged (K) at leaf mesophyll cells. (D), (H), and (L) are differential interference contrast (DIC) images for each sample. (M-P) Fluorescence of ProPLC2:PLC2-Venus (M), staining of nuclei by DAPI (N) and chlorophyll autofluorescence (O) were merged (P) at leaf mesophyll cells. Scale bars are 10 μm.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4581737&req=5

pgen.1005511.g005: Subcellular localization of fluorescent AtPLC2-Venus in 12-day-old seedlings of ProPLC2:PLC2-Venus transgenic plants.(A-D) Fluorescence of ProPLC2:PLC2-Venus (A) and staining of plasma membranes by FM4-64 dye (B) were merged (C) at stem epidermis. (E-H) Fluorescence of ProPLC2:PLC2-Venus (E) and staining of plasma membranes by FM4-64 dye (F) were merged (G) at leaf pavement and guard cells. (I-L) Fluorescence of ProPLC2:PLC2-Venus (I) and staining of plasma membranes by FM4-64 dye (J) were merged (K) at leaf mesophyll cells. (D), (H), and (L) are differential interference contrast (DIC) images for each sample. (M-P) Fluorescence of ProPLC2:PLC2-Venus (M), staining of nuclei by DAPI (N) and chlorophyll autofluorescence (O) were merged (P) at leaf mesophyll cells. Scale bars are 10 μm.
Mentions: To further study the subcellular localization of AtPLC2 in different tissues, we observed stem epidermal cells (Fig 5A–5D), leaf epidermal cells (Fig 5E–5H), and mesophyll cells (Fig 5I–5L). In all cells observed here, the Venus signals were co-localized with the plasma membrane marker FM4-64 but not with the nuclear marker 4’,6’-diamino-2’-phenylindole (DAPI) or autofluorescence of chloroplasts (Fig 5M–5P). In addition to supporting the previous study [28], these observations suggest that AtPLC2 localizes mainly at the plasma membrane in different cell types.

Bottom Line: The seedlings of plc2-1 mutant showed growth defect that was complemented by heterologous expression of AtPLC2, suggesting that phosphoinositide-specific phospholipase C activity borne by AtPLC2 is required for seedling growth.Moreover, the plc2-1 mutant showed hypersensitive response to ER stress as evidenced by changes in relevant phenotypes and gene expression profiles.Our results revealed the primary enzyme in phosphoinositide metabolism, its involvement in seedling growth and an emerging link between phosphoinositide and the ER stress response.

View Article: PubMed Central - PubMed

Affiliation: Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan; Molecular and Biological Agricultural Sciences Program, Taiwan International Graduate Program, Academia Sinica, Taipei, Taiwan; Graduate Institute of Biotechnology and Department of Life Sciences, National Chung-Hsing University, Taichung, Taiwan; Muroran Institute of Technology, Muroran, Japan.

ABSTRACT
Phosphoinositides represent important lipid signals in the plant development and stress response. However, multiple isoforms of the phosphoinositide biosynthetic genes hamper our understanding of the pivotal enzymes in each step of the pathway as well as their roles in plant growth and development. Here, we report that phosphoinositide-specific phospholipase C2 (AtPLC2) is the primary phospholipase in phosphoinositide metabolism and is involved in seedling growth and the endoplasmic reticulum (ER) stress responses in Arabidopsis thaliana. Lipidomic profiling of multiple plc mutants showed that the plc2-1 mutant increased levels of its substrates phosphatidylinositol 4-phosphate and phosphatidylinositol 4,5-bisphosphate, suggesting that the major phosphoinositide metabolic pathway is impaired. AtPLC2 displayed a distinct tissue expression pattern and localized at the plasma membrane in different cell types, where phosphoinositide signaling occurs. The seedlings of plc2-1 mutant showed growth defect that was complemented by heterologous expression of AtPLC2, suggesting that phosphoinositide-specific phospholipase C activity borne by AtPLC2 is required for seedling growth. Moreover, the plc2-1 mutant showed hypersensitive response to ER stress as evidenced by changes in relevant phenotypes and gene expression profiles. Our results revealed the primary enzyme in phosphoinositide metabolism, its involvement in seedling growth and an emerging link between phosphoinositide and the ER stress response.

No MeSH data available.