TY - JOUR
T1 - Modulation of fluorescence in Heliobacterium modesticaldum cells
AU - Collins, Aaron M.
AU - Redding, Kevin
AU - Blankenship, Robert E.
N1 - Funding Information:
Acknowledgments We would like to thank Dr. Michael Madigan for kindly providing cells of Heliobacterium modesticaldum. This study was supported by grant #NNX08AP62G from the Exobiology program of NASA to R. E. Blankenship, and a CAREER award from the NSF (MCB-0347935) and Fulbright Research grant to KR. KR also acknowledges support from the CNRS while on sabbatical at the IBPC.
PY - 2010/6
Y1 - 2010/6
N2 - In what appears to be a common theme for all phototrophs, heliobacteria exhibit complex modulations of fluorescence yield when illuminated with actinic light and probed on a time scale of μs to minutes. The fluorescence yield from cells of Heliobacterium modesticaldum remained nearly constant for the first 10-100 ms of illumination and then rose to a maximum level with one or two inflections over the course of many seconds. Fluorescence then declined to a steady-state value within about one minute. In this analysis, the origins of the fluorescence induction in whole cells of heliobacteria are investigated by treating cells with a combination of electron accepters, donors, and inhibitors of the photosynthetic electron transport, as well as varying the temperature. We conclude that fluorescence modulation in H. modesticaldum results from acceptor-side limitation in the reaction center (RC), possibly due to charge recombination between P800+ and A0-.
AB - In what appears to be a common theme for all phototrophs, heliobacteria exhibit complex modulations of fluorescence yield when illuminated with actinic light and probed on a time scale of μs to minutes. The fluorescence yield from cells of Heliobacterium modesticaldum remained nearly constant for the first 10-100 ms of illumination and then rose to a maximum level with one or two inflections over the course of many seconds. Fluorescence then declined to a steady-state value within about one minute. In this analysis, the origins of the fluorescence induction in whole cells of heliobacteria are investigated by treating cells with a combination of electron accepters, donors, and inhibitors of the photosynthetic electron transport, as well as varying the temperature. We conclude that fluorescence modulation in H. modesticaldum results from acceptor-side limitation in the reaction center (RC), possibly due to charge recombination between P800+ and A0-.
KW - Fluorescence induction
KW - Fluorescence modulation
KW - Heliobacterium modesticaldum
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U2 - 10.1007/s11120-010-9554-8
DO - 10.1007/s11120-010-9554-8
M3 - Article
C2 - 20461555
AN - SCOPUS:77953650684
SN - 0166-8595
VL - 104
SP - 283
EP - 292
JO - Photosynthesis research
JF - Photosynthesis research
IS - 2
ER -