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Measuring Spatial and Temporal Ca2+ Signals in Arabidopsis Plants
Published on: September 2, 2014
Extracellular calmodulin: A polypeptide signal in plants?
1Institute of Molecular and Cell Biology, Hebei Normal University, Shijiazhuang, China. dysun@public.sj.he.cn
Science in China. Series C, Life Sciences
|August 30, 2008
Summary
Extracellular calmodulin (CaM) acts as a novel polypeptide signal in plants, regulating cell proliferation, pollen development, and gene expression. This finding challenges the traditional view of plant intercellular signaling.
Area of Science:
- Plant molecular biology
- Cell signaling
- Biochemistry
Background:
- Calmodulin (CaM) traditionally functions as an intracellular calcium signal receptor.
- Recent research indicates CaM's presence and function in the extracellular environment of animal and plant cells.
- Extracellular CaM regulates diverse physiological processes.
Purpose of the Study:
- To investigate the role and signaling pathways of extracellular calmodulin (CaM) in plant cells.
- To determine if extracellular CaM acts as an intercellular signal in plants.
Main Methods:
- Studies on suspension-cultured plant cells and protoplasts.
- Analysis of pollen germination and pollen tube elongation.
- Investigation of light-independent gene expression (rbcS).
- Elucidation of trans-membrane and intracellular signal transduction pathways using a pollen system.
Main Results:
- Extracellular CaM stimulates plant cell proliferation and protoplast formation.
- Extracellular CaM regulates pollen germination and pollen tube elongation.
- Extracellular CaM induces light-independent gene expression of Rubisco small subunit (rbcS).
- Identified a signal transduction pathway involving G-protein, phospholipase C, IP(3), calcium signaling, and protein phosphorylation for extracellular CaM.
Conclusions:
- Extracellular CaM functions as a polypeptide signal in plants.
- This discovery challenges the established concept that plants lack intercellular polypeptide signaling.
- Extracellular CaM plays a significant role in plant growth and development.
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