Although it is well known that there are two photosystems catalyzing different photochemical reactions in the chloroplast thylakoid membrane of higher plants, yet the components of these systems are not so clear. In 1...Although it is well known that there are two photosystems catalyzing different photochemical reactions in the chloroplast thylakoid membrane of higher plants, yet the components of these systems are not so clear. In 1977, Klimov, according to the light-dark differential spectrum of photosystem Ⅱ particles and the kinetic behavior of absorption and of fluorescence intensity change at 685 nm, concluded that pheo- phytin (Pheo) was the primary electron acceptor of photosystem Ⅱ. This report attracts much interest of workers to search the evidence of pheophytin as primary elec- tron acceptor in photosynthetic process.展开更多
Spraying 1-2 mmol/L NaHSO3 on the leaf of wheat results in enhancement of photosynthesis in leaves for about 3 d. The amount of ATP has been increased and the millisecond delayed light emission of the leaves has been ...Spraying 1-2 mmol/L NaHSO3 on the leaf of wheat results in enhancement of photosynthesis in leaves for about 3 d. The amount of ATP has been increased and the millisecond delayed light emission of the leaves has been enhanced, showing that the transmembrane proton motive force related to photophosphorylation is increased. Spraying PMS (a cofactor catalyzing cycle photophosphorylation) and NaHSO3 separately or together on the leaves, 20% increase in photosynthesis has been observed in all the treatments. There is no additive effect when a mixture is applied, suggesting that the mechanism for NaHSO3 promotion of photosynthesis is similar to PMS, and both of them enhance the supply of ATP.展开更多
The proton motive force formed across the thylakoid membrane accompanying the photosynthetic electron transport can be used to synthesize ATP from ADP and inorganic phosphate for carbon assimilation. The mechanism of ...The proton motive force formed across the thylakoid membrane accompanying the photosynthetic electron transport can be used to synthesize ATP from ADP and inorganic phosphate for carbon assimilation. The mechanism of this important process has been intensively studied. However, there are still many aspects unsolved. For example: What is the ratio between the ATP and NADPH formed in noncyclic photophosphorylation and can it meet the requirement of carbon assimilation? Is there any localized proton within thylakoid membrane and is it related to the effi-展开更多
Change of proton gradient across thylakoid membrane in soybean leaves was studied with millisecond delayed light emission (ms-DLE) during the course of state transitions which were indicated by the chlorophyll fluores...Change of proton gradient across thylakoid membrane in soybean leaves was studied with millisecond delayed light emission (ms-DLE) during the course of state transitions which were indicated by the chlorophyll fluores-cence at room temperature and 77 K. When dark-adapted leaves were induced to stateⅠ with far-red light, Fm/Fo, F685/F735 and the intensity of fast phase of ms-DLE were af-fected slightly. However, during the induction to stateⅡ with red light, both Fm/Fo and F685/F735 decreased immedi-ately and the former were quicker than the latter. In this interval, the intensity of fast phase of ms-DLE increased to a maximum and then decreased to a lower value during the transition to stateⅡ. Nigericin, an uncoupler which elimi-nates the proton gradient across thylakoid membrane, inhib-ited the increase in the intensity of fast phase of ms-DLE during the transition to stateⅡ. Another uncoupler, valino-mycin, which eliminates the membrane potential, did not affect the changes of the intensity of fast phase. These results suggest that the prompt increase in the intensity of fast phase of ms-DLE at the beginning of transitions to stateⅡ is cor-related mainly with the proton gradient released from water oxidation in photosystemⅡ.展开更多
There are two proton release sites on the photosynthetic electron transport chain. One is the protons released by water oxidation of the photosystem Ⅱ （PS Ⅱ） oxygen evolution complex located on the inner side of t...There are two proton release sites on the photosynthetic electron transport chain. One is the protons released by water oxidation of the photosystem Ⅱ （PS Ⅱ） oxygen evolution complex located on the inner side of the thylakoid membrane (i. e. H<sub>H<sub>2</sub>O</sub><sup>+</sup>), the other is the protons transferred across the thylakoid membrane and released on the inner side of展开更多
文摘Although it is well known that there are two photosystems catalyzing different photochemical reactions in the chloroplast thylakoid membrane of higher plants, yet the components of these systems are not so clear. In 1977, Klimov, according to the light-dark differential spectrum of photosystem Ⅱ particles and the kinetic behavior of absorption and of fluorescence intensity change at 685 nm, concluded that pheo- phytin (Pheo) was the primary electron acceptor of photosystem Ⅱ. This report attracts much interest of workers to search the evidence of pheophytin as primary elec- tron acceptor in photosynthetic process.
文摘Spraying 1-2 mmol/L NaHSO3 on the leaf of wheat results in enhancement of photosynthesis in leaves for about 3 d. The amount of ATP has been increased and the millisecond delayed light emission of the leaves has been enhanced, showing that the transmembrane proton motive force related to photophosphorylation is increased. Spraying PMS (a cofactor catalyzing cycle photophosphorylation) and NaHSO3 separately or together on the leaves, 20% increase in photosynthesis has been observed in all the treatments. There is no additive effect when a mixture is applied, suggesting that the mechanism for NaHSO3 promotion of photosynthesis is similar to PMS, and both of them enhance the supply of ATP.
基金Project supported by the National Natural Scienoe Foundation of China
文摘The proton motive force formed across the thylakoid membrane accompanying the photosynthetic electron transport can be used to synthesize ATP from ADP and inorganic phosphate for carbon assimilation. The mechanism of this important process has been intensively studied. However, there are still many aspects unsolved. For example: What is the ratio between the ATP and NADPH formed in noncyclic photophosphorylation and can it meet the requirement of carbon assimilation? Is there any localized proton within thylakoid membrane and is it related to the effi-
基金supported by the National Natural Science Foundation of China(Grant No.30070064)the State Key Basic Research Development Plan Program(Grant No.G1998010100)
文摘Change of proton gradient across thylakoid membrane in soybean leaves was studied with millisecond delayed light emission (ms-DLE) during the course of state transitions which were indicated by the chlorophyll fluores-cence at room temperature and 77 K. When dark-adapted leaves were induced to stateⅠ with far-red light, Fm/Fo, F685/F735 and the intensity of fast phase of ms-DLE were af-fected slightly. However, during the induction to stateⅡ with red light, both Fm/Fo and F685/F735 decreased immedi-ately and the former were quicker than the latter. In this interval, the intensity of fast phase of ms-DLE increased to a maximum and then decreased to a lower value during the transition to stateⅡ. Nigericin, an uncoupler which elimi-nates the proton gradient across thylakoid membrane, inhib-ited the increase in the intensity of fast phase of ms-DLE during the transition to stateⅡ. Another uncoupler, valino-mycin, which eliminates the membrane potential, did not affect the changes of the intensity of fast phase. These results suggest that the prompt increase in the intensity of fast phase of ms-DLE at the beginning of transitions to stateⅡ is cor-related mainly with the proton gradient released from water oxidation in photosystemⅡ.
基金Project supported by the National Natural Science Foundation of China
文摘There are two proton release sites on the photosynthetic electron transport chain. One is the protons released by water oxidation of the photosystem Ⅱ （PS Ⅱ） oxygen evolution complex located on the inner side of the thylakoid membrane (i. e. H<sub>H<sub>2</sub>O</sub><sup>+</sup>), the other is the protons transferred across the thylakoid membrane and released on the inner side of
