A number of studies show that environmental stress conditions increase abscisic acid (ABA) and hydrogen peroxide (H2O2) levels in plant cells. Despite this central role of ABA in altering stomatal aperture by regulati...A number of studies show that environmental stress conditions increase abscisic acid (ABA) and hydrogen peroxide (H2O2) levels in plant cells. Despite this central role of ABA in altering stomatal aperture by regulating guard cell ion transport, little is known concerning the relationship between ABA and H2O2 in signal transduction leading to stomatal movement. Epidermal strip bioassay illustrated that ABA- inhibited stomatal opening and ABA-induced stomatal closure were abolished partly by externally added catalase (CAT) or diphenylene iodonium (DPl), which are a H2O2 scavenger and a NADPH oxidase inhibitor respectively. In contrast, internally added CAT or DPI nearly completely or partly reversed ABA-induced closure in half-stoma. Consistent with these results, whole-cell patch-clamp analysis showed that intracellular application of CAT or DPI partly abolished ABA-inhibited inward K+ current across the plasma membrane of guard cells. H2O2 mimicked ABA to inhibit inward K+ current, an effect which was reversed by the addition of ascorbic acid (Vc) in patch clamping micropipettes. These results suggested that H2O2 mediated ABA-induced stomatal movement by targeting inward K+ channels at plasma membrane.展开更多
Objective: To study the effect of isoflurane and ethanol on large conductance Ca 2+-activated K + channels(BK channels). Methods: The cRNA of mslo1 encoding BK channels was injected into Xenopus oocytes. Oocytes were ...Objective: To study the effect of isoflurane and ethanol on large conductance Ca 2+-activated K + channels(BK channels). Methods: The cRNA of mslo1 encoding BK channels was injected into Xenopus oocytes. Oocytes were incubated in ND96 (96 mmol/L NaCl, 2.0 mmol/L KCl, 1.8 mmol/L CaCl 2, 1.0 mmol/L MgCl 2, and 5.0 mmol/L HEPES, pH 7.4) at 4 ℃. Patch clamp recording (outside-out) were performed after 2-3 d. Isoflurane was administrated by the vaporizer driven by air, ethanol was applied by a closed, manual-controlled administration system. Different test potentials from 0 to 10 mV were given to observe changes of currents. Results: 0.7 mmol/L and 1.2 mmol/L of isoflurane could inhibit BK currents obviously at different command potentials, but 50 mmol/L, 100 mmol/L, or 200 mmol/L of ethanol had no any effect on BK currents. Conclusion: Clinical concentration of isoflurane can distinctly inhibit isolating BK currents.展开更多
In a previous paper [Commun. Theor. Phys., [arxiv：hep-ph/11081451]], guish poles of different dynamical origin, in unitarized amplitudes of ππ, K K system. that ＂A Breit-wigner resonance should exhibit two poles o...In a previous paper [Commun. Theor. Phys., [arxiv：hep-ph/11081451]], guish poles of different dynamical origin, in unitarized amplitudes of ππ, K K system. that ＂A Breit-wigner resonance should exhibit two poles on different Riemann sheets axis when Nc = ∞＂. In this paper, we extend our previous work [Commun. Theor. to the ππ-KK=ηη three channel system. We reconfirm most of the predictions in our Phys., [arxiv：hep-ph/11081451]]. Especially the fo（980） is of KK molecule nature. 0 Breit-WJgner type. we proposed a method to distinThat is based on the observation which meet each other on the real phys,[arXiv：hep,ph/11081451]]pres.ious work ： Theor. ther poles, including the σ,are of Breit-wigner type.展开更多
基金National Natura1 Science Foundation of China (No. 39870372),StateKey Basic Research and Development Project (No.G1999011700)
文摘A number of studies show that environmental stress conditions increase abscisic acid (ABA) and hydrogen peroxide (H2O2) levels in plant cells. Despite this central role of ABA in altering stomatal aperture by regulating guard cell ion transport, little is known concerning the relationship between ABA and H2O2 in signal transduction leading to stomatal movement. Epidermal strip bioassay illustrated that ABA- inhibited stomatal opening and ABA-induced stomatal closure were abolished partly by externally added catalase (CAT) or diphenylene iodonium (DPl), which are a H2O2 scavenger and a NADPH oxidase inhibitor respectively. In contrast, internally added CAT or DPI nearly completely or partly reversed ABA-induced closure in half-stoma. Consistent with these results, whole-cell patch-clamp analysis showed that intracellular application of CAT or DPI partly abolished ABA-inhibited inward K+ current across the plasma membrane of guard cells. H2O2 mimicked ABA to inhibit inward K+ current, an effect which was reversed by the addition of ascorbic acid (Vc) in patch clamping micropipettes. These results suggested that H2O2 mediated ABA-induced stomatal movement by targeting inward K+ channels at plasma membrane.
文摘Objective: To study the effect of isoflurane and ethanol on large conductance Ca 2+-activated K + channels(BK channels). Methods: The cRNA of mslo1 encoding BK channels was injected into Xenopus oocytes. Oocytes were incubated in ND96 (96 mmol/L NaCl, 2.0 mmol/L KCl, 1.8 mmol/L CaCl 2, 1.0 mmol/L MgCl 2, and 5.0 mmol/L HEPES, pH 7.4) at 4 ℃. Patch clamp recording (outside-out) were performed after 2-3 d. Isoflurane was administrated by the vaporizer driven by air, ethanol was applied by a closed, manual-controlled administration system. Different test potentials from 0 to 10 mV were given to observe changes of currents. Results: 0.7 mmol/L and 1.2 mmol/L of isoflurane could inhibit BK currents obviously at different command potentials, but 50 mmol/L, 100 mmol/L, or 200 mmol/L of ethanol had no any effect on BK currents. Conclusion: Clinical concentration of isoflurane can distinctly inhibit isolating BK currents.
基金Supported in part by National Nature Science Foundations of China under Grant Nos.10925522 and 10875001
文摘In a previous paper [Commun. Theor. Phys., [arxiv：hep-ph/11081451]], guish poles of different dynamical origin, in unitarized amplitudes of ππ, K K system. that ＂A Breit-wigner resonance should exhibit two poles on different Riemann sheets axis when Nc = ∞＂. In this paper, we extend our previous work [Commun. Theor. to the ππ-KK=ηη three channel system. We reconfirm most of the predictions in our Phys., [arxiv：hep-ph/11081451]]. Especially the fo（980） is of KK molecule nature. 0 Breit-WJgner type. we proposed a method to distinThat is based on the observation which meet each other on the real phys,[arXiv：hep,ph/11081451]]pres.ious work ： Theor. ther poles, including the σ,are of Breit-wigner type.
