Action Spectrum for Interaction between Visible and Far-Red Light on Face Chloroplast Orientation in Mougeotia1
AUTOR(ES)
Lechowski, Zbigniew
RESUMO
The orientation of chloroplasts from profile to face position in Mougeotia can be controlled in two ways: by a typical phytochrome-mediated system or by continuous, simultaneous irradiation with far-red and visible light. In experiments with dichromatic irradiation of Mougeotia, the light conditions applied prevented the formation of a far-red-absorbing form of phytochrome gradient in the cell. An unpolarized background of far-red light and linearly polarized monochromatic light of different wavelengths and vibrating parallel to the cell axis, if given by themselves, were completely ineffective in producing any changes in chloroplast orientation. Given together, however, changes in chloroplast orientation were induced. The action spectrum for this interaction between constant far-red and variable visible light was maximal at 620 nanometers. The chloroplast response in these dichromatic light conditions required a prolonged duration of exposure to simultaneous continuous irradiation of high fluence energy. The vibrating plane of linearly polarized 620 nanometer light had no significant influence on interaction with far-red light in chloroplast movement. The results obtained are different from the typical low energy phytochrome-mediated chloroplast orientation. This new type of chloroplast photoresponse might be mediated by an unknown sensory pigment.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1055547Documentos Relacionados
- Interaction between Green and Far-Red Light on the Low Fluence Rate Chloroplast Orientation in Mougeotia
- Influence of Light on Phosphate Metabolism in Lettuce Seed: Spectral Response Red, Far-Red Interaction 12
- An Arabidopsis mutant hypersensitive to red and far-red light signals.
- Differential Transcription of Pea Chloroplast Genes during Light-Induced Leaf Development (Continuous Far-Red Light Activates Chloroplast Transcription).
- Effect of Far-Red Light and its Interaction with Red Light in the Photoperiodic Response of Pharbitis nil12