Protection of Photosynthesis against Ultraviolet-B Radiation by Carotenoids in Transformants of the Cyanobacterium Synechococcus PCC79421
AUTOR(ES)
Götz, Thomas
FONTE
American Society of Plant Physiologists
RESUMO
The cyanobacterium Synechococcus PCC7942 was transformed with various carotenogenic genes, and the resulting transformants either accumulated higher amounts of β-carotene and zeaxanthin or showed a shift in the carotenoid pattern toward the formation of zeaxanthin. These transformants were exposed to ultraviolet-B (UV-B) radiation, and the degradation of phycobilins, the inactivation of photosynthetic oxygen evolution, and the activity of photosystem II were determined. In the genetically modified cells, the influence on destruction of phycobilins was negligible. However, protection of photosynthetic reactions against UV-B damage was observed and was dependent on the carotenoid concentrations in the different transformants. Furthermore, it was shown that endogenous zeaxanthin is more effective than β-carotene. Our results suggest that carotenoids exert their protective function as antioxidants to inactivate UV-B-induced radicals in the photosynthetic membrane.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=59299Documentos Relacionados
- Iron Superoxide Dismutase Protects against Chilling Damage in the Cyanobacterium Synechococcus species PCC79421
- Inhibition of Seagrass Photosynthesis by Ultraviolet-B Radiation 1
- Effects of Ultraviolet-B Irradiances on Soybean: II. INTERACTION BETWEEN ULTRAVIOLET-B AND PHOTOSYNTHETICALLY ACTIVE RADIATION ON NET PHOTOSYNTHESIS, DARK RESPIRATION, AND TRANSPIRATION 1
- Characterization of Stomatal Closure Caused by Ultraviolet-B Radiation1
- Ultraviolet-B Radiation Effects on Water Relations, Leaf Development, and Photosynthesis in Droughted Pea Plants1
