Nonphotosynthetic reduction of the intersystem electron transport chain of chloroplasts following heat stress. Steady-state rate.
The consequence of elevated temperatures in the range of 39-51 degrees C on the steady-state rate of light-induced electron transport through photosystem I (PSI) supported by stromal reductants was studied in intact barley leaves using photoacoustic and chlorophyll fluorescence techniques. Measurable electron flow through PSI in diuron-treated leaves occurred only after exposure to temperatures above 37 degrees C. The steady-state rate of the above diuron-insensitive electron flow with methyl viologen as electron acceptor was estimated to be 3.7 mu eq m-2 s-1 or 0.018 mu eq mumol chlorophyll-1 s-1 in leaves exposed for 5 min to 45 degrees C.
Bukhov
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NG
K. A. Timiriazev Institute of Plant Physiology, Russian Academy of Sciences, Moscow, Russia.
Samson
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G
Carpentier
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R
D004579:Electron Transport; D001467:Hordeum / Q000378:metabolism*; D006358:Hot Temperature