scholarly journals Ferredoxin Limits Cyclic Electron Flow around PSI (CEF-PSI) in Higher Plants—Stimulation of CEF-PSI enhances Non-Photochemical Quenching of Chl Fluorescence in Transplastomic Tobacco

2006 ◽  
Vol 47 (10) ◽  
pp. 1355-1371 ◽  
Author(s):  
Hiroshi Yamamoto ◽  
Hideki Kato ◽  
Yuki Shinzaki ◽  
Sayaka Horiguchi ◽  
Toshiharu Shikanai ◽  
...  
Keyword(s):  
Higher Plants ◽  
Electron Flow ◽  
Cyclic Electron Flow ◽  
Photochemical Quenching ◽  
Transplastomic Tobacco ◽  
Non Photochemical Quenching ◽  
Stimulation Of ◽  
Chl Fluorescence

scholarly journals Effects of Light Intensity on Cyclic Electron Flow Around PSI and its Relationship to Non-photochemical Quenching of Chl Fluorescence in Tobacco Leaves

2005 ◽  
Vol 46 (11) ◽  
pp. 1819-1830 ◽  
Author(s):  
Chikahiro Miyake ◽  
Sayaka Horiguchi ◽  
Amane Makino ◽  
Yuki Shinzaki ◽  
Hiroshi Yamamoto ◽  
...  
Keyword(s):  
Light Intensity ◽  
Electron Flow ◽  
Cyclic Electron Flow ◽  
Photochemical Quenching ◽  
Tobacco Leaves ◽  
Non Photochemical Quenching ◽  
Chl Fluorescence

scholarly journals Exogenous putrescine alleviates photoinhibition caused by salt stress through increasing cyclic electron flow in cucumber

2018 ◽  
Author(s):  
Xinyi Wu ◽  
Sheng Shu ◽  
Yu Wang ◽  
Ruonan Yuan ◽  
Shirong Guo
Keyword(s):  
Salt Stress ◽  
Electron Flow ◽  
Critical Role ◽  
Photochemical Efficiency ◽  
Cyclic Electron Flow ◽  
Photochemical Quenching ◽  
Photochemical Efficiency Of Psii ◽  
High Level ◽  
Non Photochemical Quenching ◽  
Related Proteins

AbstractWhen plants suffer from abiotic stresses, cyclic electron flow (CEF) is induced for photoprotection. Putrescine (Put), a main polyamine in chloroplasts, plays a critical role in stress tolerance. To elucidate the mechanism of Put regulating CEF for salt-tolerance in cucumber leaves, we measured chlorophyll fluorescence, P700 redox state, ATP and NADPH accumulation and so on. The maximum photochemical efficiency of PSII (Fv/Fm) was not influenced by NaCl and/or Put, but the activity of PSI reaction center (P700) was seriously inhibited by NaCl. Salt stress induced high level of CEF, moreover, NaCl and Put treated plants exhibited much higher CEF activity and ATP accumulation than single salt-treated plants to provide adequate ATP/NADPH ratio for plants growth. Furthermore, Put decreased the trans-membrane proton gradient (ΔpH), accompanied by reducing the pH-dependent non-photochemical quenching (qE) and increasing efficient quantum yield of PSII (Y(II)). The ratio of NADP+/NADPH in salt stressed leaves was significantly increased by Put, indicating that Put relieved over-reduction pressure at PSI accepter side. Taken together, our results suggest that exogenous Put enhances CEF to supply extra ATP for PSI recovery and CO2 assimilation, decreases ΔpH for electron transport related proteins staying active, and enable the non-photochemical quenching transformed into photochemical quenching.

scholarly journals Restoration of Rapidly Reversible Photoprotective Energy Dissipation in the Absence of PsbS Protein by Enhanced ΔpH

2011 ◽  
Vol 286 (22) ◽  
pp. 19973-19981 ◽  
Author(s):  
Matthew P. Johnson ◽  
Alexander V. Ruban
Keyword(s):  
Higher Plants ◽  
Electron Flow ◽  
Photosynthetic Electron Transport ◽  
Reaction Centers ◽  
Photochemical Quenching ◽  
Spectral Changes ◽  
Intact Chloroplasts ◽  
Harvesting Process ◽  
Non Photochemical Quenching ◽  
Psbs Protein

Variations in the light environment require higher plants to regulate the light harvesting process. Under high light a mechanism known as non-photochemical quenching (NPQ) is triggered to dissipate excess absorbed light energy within the photosystem II (PSII) antenna as heat, preventing photodamage to the reaction center. The major component of NPQ, known as qE, is rapidly reversible in the dark and dependent upon the transmembrane proton gradient (ΔpH), formed as a result of photosynthetic electron transport. Using diaminodurene and phenazine metasulfate, mediators of cyclic electron flow around photosystem I, to enhance ΔpH, it is demonstrated that rapidly reversible qE-type quenching can be observed in intact chloroplasts from Arabidopsis plants lacking the PsbS protein, previously believed to be indispensible for the process. The qE in chloroplasts lacking PsbS significantly quenched the level of fluorescence when all PSII reaction centers were in the open state (Fo state), protected PSII reaction centers from photoinhibition, was modulated by zeaxanthin and was accompanied by the qE-typical absorption spectral changes, known as ΔA535. Titrations of the ΔpH dependence of qE in the absence of PsbS reveal that this protein affects the cooperativity and sensitivity of the photoprotective process to protons. The roles of PsbS and zeaxanthin are discussed in light of their involvement in the control of the proton-antenna association constant, pK, via regulation of the interconnected phenomena of PSII antenna reorganization/aggregation and hydrophobicity.

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