A simple chlorophyll fluorescence parameter that correlates with the rate coefficient of photoinactivation of Photosystem II
A simple chlorophyll fluorescence parameter that correlates with the rate coefficient of photoinactivation of Photosystem II
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DOI：
10.1007/s11120-004-6430-4
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发表时间：
2005-06-01
影响因子：
3.7
通讯作者：
Chow, WS
中科院分区：
文献类型：
--
作者：
Hendrickson, L;Förster, B;Chow, WS
A method of partitioning the energy in a mixed population of active and photoinactivated Photosystem II (PS II) complexes based on chlorophyll fluorescence measurements is presented. There are four energy fluxes, each with its quantum efficiency: a flux associated with photochemical electron flow in active PS II reaction centres (J(PS II)), thermal dissipation in photoinactivated, non-functional PS IIs (J(NF)), light-regulated thermal dissipation in active PS IIs (J(NPQ)) and a combined flux of fluorescence and constitutive, light-independent thermal dissipation (J(f,D)). The four quantum efficiencies add up to 1.0, without the need to introduce an 'excess' term E, which in other studies has been claimed to be linearly correlated with the rate coefficient of photoinactivation of PS II (k(pi)). We examined the correlation of k(pi) with various fluxes, and found that the combined flux (J(NPQ) + J(f,D)= J(pi)) is as well correlated with k(pi) as is E. This combined flux arises from F-s/F-m', the ratio of steady-state to maximum fluorescence during illumination, which represents the quantum efficiency of combined non-photochemical dissipation pathways in active PS IIs. Since F-s/F-m' or its equivalent, J(pi), is a likely source of events leading to photoinactivation of PS II, we conclude that F-s/F-m' is a simple predictor of k(pi).
