An Investigation of the Sustained Component of Nonphotochemical Quenching of Chlorophyll Fluorescence in Isolated Chloroplasts and Leaves of Spinach

Ruban, Alexander V.; Horton, Peter

doi:10.1104/pp.108.2.721

Cited by 94 publications

(58 citation statements)

References 17 publications

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“…There is additional complexity because the activity of the violaxanthin deepoxidase, which determined the DEPS, was dependent on the lumen pH (Pfü ndel and Bilger, 1994;Eskling et al, 1997), and this dependency was also subject to light activation (Delrieu, 1998). It is also important to point out that the development of the light-activated state, for both chloroplasts and leaves, was associated with a sustained qN and an associated decrease in F v /F m , which is in agreement with previous work (Ruban and Horton, 1995a).…”

Section: Discussionsupporting

confidence: 78%

The Xanthophyll Cycle Modulates the Kinetics of Nonphotochemical Energy Dissipation in Isolated Light-Harvesting Complexes, Intact Chloroplasts, and Leaves of Spinach1

1999

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We analyzed the kinetics of nonphotochemical quenching of chlorophyll fluorescence (qN) in spinach (Spinacia oleracea) leaves, chloroplasts, and purified light-harvesting complexes. The characteristic biphasic pattern of fluorescence quenching in dark-adapted leaves, which was removed by preillumination, was evidence of light activation of qN, a process correlated with the de-epoxidation state of the xanthophyll cycle carotenoids. Chloroplasts isolated from dark-adapted and light-activated leaves confirmed the nature of light activation: faster and greater quenching at a subsaturating transthylakoid pH gradient. The light-harvesting chlorophyll a/bbinding complexes of photosystem II were isolated from darkadapted and light-activated leaves. When isolated from lightactivated leaves, these complexes showed an increase in the rate of quenching in vitro compared with samples prepared from darkadapted leaves. In all cases, the quenching kinetics were fitted to a single component hyperbolic function. For leaves, chloroplasts, and light-harvesting complexes, the presence of zeaxanthin was associated with an increased rate constant for the induction of quenching. We discuss the significance of these observations in terms of the mechanism and control of qN.Under different physiological conditions the efficiency with which absorbed light energy is harvested by photosynthesis is altered by the operation of a regulatory mechanism that determines how much excitation energy is used and how much is dissipated as heat (Horton, 1987; Demmig-Adams and Adams, 1992;Horton and Ruban, 1992; Bjö rkman and Demmig-Adams, 1995; DemmigAdams et al., 1995). The function of this mechanism is to harmlessly dissipate excess energy when photosynthesis is light saturated, thereby protecting the pigments and proteins of the chloroplast membrane from photo damage. The extent of energy dissipation, measured by the quenching of chlorophyll fluorescence, has been found to correlate with the extent of de-epoxidation of the xanthophyll cycle carotenoids (Demmig-Adams, 1990).The kinetics of the formation and relaxation of quenching and the effects of inhibitors established the role of the energization of thylakoid by the ⌬pH, so this quenching was referred to as qE (Briantais et al., 1979). It is therefore widely accepted that these two factors control the induction of qE . Various reports suggest that qE occurs in LHCII Horton et al., 1996), where the xanthophyll cycle carotenoids are bound (Peter and Thornber, 1991; Bassi et al., 1993;Ruban et al., 1994b) and where proton-active sites involved in qE have been identified Pesaresi et al., 1997). It has been suggested that CP26 and CP29, two of the minor components of LHCII, have a major role in qE Bassi et al., 1993; Crofts and Yerkes, 1994;Walters et al., 1994;Pesaresi et al., 1997;Gilmore et al., 1996b).It is unclear how the xanthophyll cycle and qE are related. Some have suggested that the de-epoxidized pigments antheraxanthin and zeaxanthin directly quench excited chlorophyll singlet states (Demmi...

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Section: Discussionsupporting

confidence: 78%

The Xanthophyll Cycle Modulates the Kinetics of Nonphotochemical Energy Dissipation in Isolated Light-Harvesting Complexes, Intact Chloroplasts, and Leaves of Spinach1

1999

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“…The data showing that preceding sowing incubation of seeds in ZEN solutions resulted in an increase in the nonphotochemical quenching (qE, qT) during strong illumination for both species (Table 4) are consistent with the opinions of other authors (Fork and Satoh 1986;Horton and Hauge 1988;van Wijk and van Hasselt 1993;Ting and Owens 1994;Ruban and Horton 1995;Owens 1996;Haldrup et al 2001) that such response may be recognized as the action of the first defense line for the photosynthetic apparatus against photoinhibitory injuries and other photooxidative ones. In our experiment it was observed that ZEN prevented photoinhibitory injuries during strong illumination due to the safe dissipation of the excess of absorbed light energy through mechanisms related to the development of pH gradient (qE) in thylakoids and phosphorylation of LHC2 (qT).…”

Section: Photoinhibitory Reactions Of Psiisupporting

confidence: 77%

“…The non-photochemical quench qN is based on three major constituents: the energy quenching qE, qT and qI caused by a photoinhibition of PSII units (Fork and Satoh 1986;Horton and Hauge 1988;van Wijk and van Hasselt 1993;Ting and Owens 1994;Ruban and Horton 1995;Owens 1996;Haldrup et al 2001). qE is thought to occur in PSII antennae and there is evidence that it is regulated by the pH gradient across the thylakoid membrane and by the interconversion of pigments in the xanthophylls cycle (Owens 1996;Ting and Owens 1994;Ruban and Horton 1995). The photoinhibitory quenching qI is caused by the photoinhibition of PSII units (Greer et al 1986;Baker 1994;Owens 1996).…”

Section: Measurements Of Psii Photoinhibitionmentioning

confidence: 99%

The effect of zearalenone on PSII photochemical activity and growth in wheat and soybean under salt (NaCl) stress

et al. 2011

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The effects of mycotoxin zearalenone (ZEN) on the photochemical activity of photosystem II (PSII) in wheat and soybean leaf discs incubated in ZEN solutions as well as the after-effects of pre-sowing soaking of seeds in solutions containing ZEN on the photochemical activity of PSII and on the seedlings growth under salt stress (NaCl solutions were investigated). The incubation of wheat leaf discs in ZEN solutions strongly inhibited the energy flux per cross section (CS) for absorption (ABS/CS), trapping (TRo/CS) and electron transport (ETo/CS), while the effects of ZEN action on soybean discs were opposite and the values of those parameters significantly increased with the increase in ZEN concentration. Incubation of seeds in a ZEN solution resulted in an increase in photochemical efficiency of PSII in soybean seedlings, but did not induce any response of PSII in those of wheat at medium illuminations. Only at the stronger illumination for both species did ZEN induce an increase in efficiency of excitation energy capture by open PSII reaction centers, photochemical quenching of chlorophyll a fluorescence and quantum yield of PSII electron transport. Pre-sowing soaking of seeds in a ZEN solution decreased the photoinhibitory injuries of PSII in wheat and soybean due to safe scattering of the excess excitation energy through an increase in energy-dependent quenching (qE) and state transition quenching (qT). ZEN when added to NaCl solutions during the period of germination contributed to reduction in the growth inhibition of wheat seedlings. The incubation of wheat leaf discs in ZEN solutions strongly inhibited CS, ABS/CS, TRo/CS and ETo/CS. Possible effects of ZEN on some physiological processes in plants have been discussed especially in the context with photochemical activity of PSII and a salt stress.

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“…Previous work led to different proposals for mechanisms leading to fluorescence recovery components with intermediate half-life between qE and qI. First, it was attributed to state 1-state 2 transitions [43]; second to PSII photoinhibition [51]; third to a slowly developing component of qE dependent on Zea [52]; fourth to light-induced dissociation of the complex Lhcb4-Lhcb6-LHCII-M [19]. Here, we show that qM did not correlate with Zea accumulation nor was it related to qI.…”

Section: (C) Chloroplast Avoidance Response and Qmmentioning

confidence: 99%

On the origin of a slowly reversible fluorescence decay component in the Arabidopsis npq4 mutant

Dall’Osto

Cazzaniga

Wada

et al. 2014

Phil. Trans. R. Soc. B

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Over-excitation of photosynthetic apparatus causing photoinhibition is counteracted by non-photochemical quenching (NPQ) of chlorophyll fluorescence, dissipating excess absorbed energy into heat. The PsbS protein plays a key role in this process, thus making the PsbS-less npq4 mutant unable to carry out qE, the major and most rapid component of NPQ. It was proposed that npq4 does perform qE-type quenching, although at lower rate than WT Arabidopsis. Here, we investigated the kinetics of NPQ in PsbS-depleted mutants of Arabidopsis. We show that red light was less effective than white light in decreasing maximal fluorescence in npq4 mutants. Also, the kinetics of fluorescence dark recovery included a decay component, qM, exhibiting the same amplitude and half-life in both WT and npq4 mutants. This component was uncouplersensitive and unaffected by photosystem II repair or mitochondrial ATP synthesis inhibitors. Targeted reverse genetic analysis showed that traits affecting composition of the photosynthetic apparatus, carotenoid biosynthesis and state transitions did not affect qM. This was depleted in the npq4phot2 mutant which is impaired in chloroplast photorelocation, implying that fluorescence decay, previously described as a quenching component in npq4 is, in fact, the result of decreased photon absorption caused by chloroplast relocation rather than a change in the activity of quenching reactions.

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An Investigation of the Sustained Component of Nonphotochemical Quenching of Chlorophyll Fluorescence in Isolated Chloroplasts and Leaves of Spinach

Cited by 94 publications

References 17 publications

The Xanthophyll Cycle Modulates the Kinetics of Nonphotochemical Energy Dissipation in Isolated Light-Harvesting Complexes, Intact Chloroplasts, and Leaves of Spinach1

The Xanthophyll Cycle Modulates the Kinetics of Nonphotochemical Energy Dissipation in Isolated Light-Harvesting Complexes, Intact Chloroplasts, and Leaves of Spinach1

The effect of zearalenone on PSII photochemical activity and growth in wheat and soybean under salt (NaCl) stress

On the origin of a slowly reversible fluorescence decay component in the Arabidopsis npq4 mutant

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