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Updated: May 6, 2026
11:49
Characterization of G Protein-coupled Receptors by a Fluorescence-based Calcium Mobilization Assay
Published on: July 28, 2014
44.0K
Cyclic GMP and calcium mediate phytochrome phototransduction
C Bowler1, G Neuhaus, H Yamagata
1Laboratory of Plant Molecular Biology, Rockefeller University, New York, New York 10021-6399.
Cell
|April 8, 1994
Summary
Cyclic GMP (cGMP) and calcium are key regulators of plant development. cGMP triggers anthocyanin production, while cGMP with calcium promotes mature chloroplast development by modulating gene expression.
Area of Science:
- Plant biology
- Molecular signaling
- Photosynthesis research
Background:
- Phytochrome signaling in plants involves G proteins, calcium, and calmodulin.
- G protein activation aids chloroplast development and anthocyanin synthesis.
- Calcium and calmodulin alone stimulate immature chloroplasts and cannot induce anthocyanins.
Purpose of the Study:
- To investigate the role of cyclic GMP (cGMP) in phytochrome signaling.
- To determine the combined effects of cGMP and calcium on chloroplast development and anthocyanin production.
- To elucidate the molecular mechanisms by which cGMP and calcium regulate these processes.
Main Methods:
- Single-cell assays in a phytochrome-deficient tomato mutant.
- Utilizing reporter genes (cab-gus, chs-gus, fnr-gus) to monitor gene expression.
- Biochemical analysis of chloroplast development and pigment biosynthesis.
Main Results:
- cGMP alone can trigger anthocyanin production.
- A combination of cGMP and calcium induces fully mature chloroplasts with complete photosynthetic machinery.
- Reporter gene assays demonstrate that cGMP and calcium primarily modulate gene expression.
Conclusions:
- cGMP is a critical signaling molecule in phytochrome pathways, alongside G proteins, calcium, and calmodulin.
- The synergistic action of cGMP and calcium is essential for complete chloroplast maturation and function.
- Gene expression modulation is the primary mechanism through which cGMP and calcium exert their effects in plant development.
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