Localization of phytochrome in oats by electron microscopy
J P Verbelen1, L H Pratt, W L Butler
1Department of Biology, University of California, San Diego, La Jolla, California 92093.
Plant Physiology
|September 1, 1982
Summary
Red light triggers phytochrome redistribution in oat coleoptiles, accumulating in vacuoles. This photomorphogenesis research reveals light-induced cellular changes in plants.
Area of Science:
- Plant biology
- Cell biology
- Photomorphogenesis
Background:
- Phytochrome is a key photoreceptor regulating plant growth and development in response to light.
- Understanding phytochrome localization is crucial for elucidating light-mediated signaling pathways.
Purpose of the Study:
- To investigate the cellular localization of phytochrome in oat coleoptiles under different light conditions.
- To determine the effect of red light illumination on phytochrome distribution.
Main Methods:
- Immunoelectron microscopy was employed to visualize phytochrome in etiolated and irradiated oat (Avena sativa) seedlings.
- Ultrathin frozen sections and immunopurified, monospecific antibodies were used to enhance assay sensitivity and resolution.
Main Results:
- In etiolated seedlings, phytochrome showed a diffuse appearance.
- Brief red light illumination induced phytochrome redistribution to a particulate form, accumulating within small vacuoles.
- In continuously illuminated or light-grown plants, phytochrome distribution was similar to dark-grown material, with a notable positive reaction in the nucleus of green plants.
Conclusions:
- Red light induces rapid sequestration of phytochrome into vacuoles in oat coleoptile cells.
- Phytochrome localization changes dynamically in response to light signals, influencing plant development.
- The nucleus becomes a site of phytochrome accumulation in light-exposed, greening tissues.
