Nonphotochemical quenching , light

Michael Wasielewski of Northwestern University asked Thomas Moore about the type of light fluxes being used to investigate the solar flux. He also asked, Since we all know that photosynthesis has control mechanisms that actually modify electron flow, based on light flux, what kind of prospectus or perspective do we have for control mechanisms in such systems Moore explained that one of the factors that seems to limit natural photosynthesis is the diffusion of carbon dioxide into the system for fixing, so it is important in photosynthesis to throttle back the powerful oxidant when carbon dioxide is limiting. There is a control mechanism called nonphotochemical quenching that is related to the... 

Fig. 18. Schematic model of the presumed mechanism for rapidly reversible nonphotochemical quenching (q ) and the proposed mechanism for sustained NPQ (q,). LHCs = light-harvesting complexes of PS II LHCII = major, peripheral light-harvesting complex of PS II LHCII-P = phosphorylated LHCII Z = zeaxanthin...

Horton P (1996) Nonphotochemical quenching of chlorophyll fluorescence. In Jennings RC, Zucchelli G, Ghetti F and Colombetti G (eds) Light as an Energy Source and Information Carrier in Plant Physiology, pp 99-111. Plenum Press, New York... 

Fig. 5.30 General behaviour of the chlorophyll a fluorescence after exposing a dark-adapted leaf to light. The fluorescence intensity first increases due to a decrease of photochemical quenching (a) and then decreases due to an increase of nonphotochemical quenching (b)...

Standfuss J, Terwisscha van Scheltinga AC, Lamborghini M, Kuhlbrandt W (2005) Mechanisms of photoprotection and nonphotochemical quenching in pea light-harvesting complex at 2.5 A resolution. EMBO J 24(5) 919-928... 

Owens TG, Shreve AP and Albrecht AC (1992) Dynamics and mechanism of singlet energy transfer between carotenoids and chlorophylls Light harvesting and nonphotochemical fluorescence quenching. In Murata N (ed) Research in Photosynthesis, Vol 4, pp 179-186. Kluwer Academic Publishers, Dordrecht... 

Evidence for a causal relationship between zeaxanthin and radiationless energy dissipation. Figure 1 shows a typical time course of nonphotochemical fluorescence quenching which develops in leaves upon exposure to an excess of light. Such... 

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