Effect of Supplementary UVB Radiation on Chlorophyll Synthesis and Accumulation of Photosystems during Chloroplast Development in Spirodela oligorrhiza

摘要: — Although the effects of ultraviolet B (UVB, 290–320 nm) radiation have been studied in plants extensively, little is known about potential impacts on maturation chloroplasts. To address this problem, supplementary UVB chloroplast development were examined aquatic higher plant Spirodela oligorrhiza. Dark-grown Spirodela-containing proplastids exposed to photosynthetically active (PAR) and A (UVA, 320–400 nm), plus equivalent 1% PAR a photon basis. The biosynthesis assembly chlorophyll (Chi) into reaction centers was followed for 4 days situ by low temperature (77 K) Chi fluorescence. Impacts detected after only 1 h incubation light with UVB. Fluorescence emission signals from associated photosystem (PS) II antenna, PSII PSI at same time or without UVB, but magnitude PS fluorescence diminished up 60% incubated content also lower UVB-treated plants, lesser degree than anticipated fluorescence, suggesting lack organization and/or association PS. Electron transport, measured room induction, not consistently different These results suggest that fewer smaller form during development, there large inhibition synthesis activity.