The long-wavelength limit of plant photosynthesis.
It is a common knowledge that the photosynthesis efficiency drops rapidly under the long-wavelength light excitation above 680 nm. We discovered that in sunflower leaves attached to the plant the initial fall is replaced by an unexpected increase at much longer wavelengths, so that a detectable O(2) evolution is remained till 780 nm. The quantum yield of O(2) evolution at the local maximum at 745 nm reaches almost 20% of the yield at 650 nm. We conclude that extreme long-wavelength chlorophylls may be present in the intact photosystem II antenna system, similarly to photosystem I.
Pettai
Hugo
H
Institute of Molecular and Cell Biology, University of Tartu, Riia 23, Tartu 51010, Estonia.
Oja
Vello
V
Freiberg
Arvi
A
Laisk
Agu
A
D055592:Biophysical Phenomena; D001703:Biophysics; D002734:Chlorophyll / Q000378:metabolism; D045342:Light-Harvesting Protein Complexes; D046911:Macromolecular Substances; D010100:Oxygen / Q000378:metabolism; D010788:Photosynthesis; D045322:Photosynthetic Reaction Center Complex Proteins; D045331:Photosystem I Protein Complex / Q000378:metabolism; D045332:Photosystem II Protein Complex / Q000378:metabolism; D018521:Plant Physiological Phenomena; D013696:Temperature; D013997:Time Factors
D045342:Light-Harvesting Protein Complexes; D046911:Macromolecular Substances; D045322:Photosynthetic Reaction Center Complex Proteins; D045331:Photosystem I Protein Complex; D045332:Photosystem II Protein Complex; D002734:Chlorophyll; D010100:Oxygen