Characteristics of dormancy induction and alternative respiration pathway (also known as cyanide-resistant respiration) of nectarine flower buds in different photoperiods were studied to determine the function of ph...Characteristics of dormancy induction and alternative respiration pathway (also known as cyanide-resistant respiration) of nectarine flower buds in different photoperiods were studied to determine the function of photoperiod and alternative respiration pathway in dormancy induction. Oxygen-electrode system and respiratory inhibitors were used to measure total respiratory rates and rates of alternative respiration pathway. The results showed that total respiration rate (Vt) in flower buds showed to be double hump-shaped curves. Short day raised, brought the first-hump of Vt forward and delayed the second-hump, while long day delayed the whole curve. The capacity (Vast) and activity (pValt) of SD and LD changed synchronously and both showed to be double hump-shaped curves. Short day made the first climax of Vast and pValt existed much earlier, while long day increased their rates significantly. The length of day had little effects on the later period climax. Long day also increased the contributions of altemative respiration pathway in total respiration rate (pValt/Vt). The changes in alternative respiration pathway were correlated with the induction of dormancy and adjusted by photoperiod. Short day promoted dormancy induction of nectarine trees, while long day delayed it.展开更多
Effects of inhibitors and glucose on cytochrome and alternative respiration and on adenylate energy charge (AEC) in glucose starved Chlorella protothecoides were investigated. 1 mmol/L azide (NaN 3), which immediate...Effects of inhibitors and glucose on cytochrome and alternative respiration and on adenylate energy charge (AEC) in glucose starved Chlorella protothecoides were investigated. 1 mmol/L azide (NaN 3), which immediately caused an increase of O 2 uptake by inhibiting the cytochrome pathway and stimulating alternative respiration, resulted in a decrease of AEC value from 0.83 to 0.34 within 3 minutes. When 1 mmol/L salicylhydroxamic acid (SHAM) was added into the cell suspension, there was no apparent variation in AEC. Adding NaN 3 and SHAM together into cell suspension to inhibit both cytochrome and alternative pathways showed a same change of AEC as that of adding NaN 3 alone. When 2.0 mmol/L of glucose was added to a suspension of glucose starved cells, the O 2 uptake rate was immediately stimulated from 0.81 up to 1.34 [μmol/L O 2[DK]·min -1 ·(mL PCV) -1 ]. The respiration stimulated by glucose could be inhibited about 20% by adding 1 mmol/L SHAM. It was found by titration with SHAM in the absence and presence of NaN 3 that 53% of O 2 uptake went through the cytochrome pathway and 45% of the alternate pathway was operational in enhanced respiration. It implied that induced operation of the alternative respiratory pathway probably resulted from the burst of the electron flux into the electron transport chain by glucose stimulation. . The respiration stimulated by glucose could be inhibited about 20% by adding 1 mmol/L SHAM. It was found by titration with SHAM in the absence and presence of NaN 3 that 53% of O 2 uptake went through the cytochrome pathway and 45% of the alternate pathway was operational in enhanced respiration. It implied that induced operation of the alternative respiratory pathway probably resulted from the burst of the electron flux into the electron transport chain by glucose stimulation.展开更多
Cultivars of maize (Zea mays L.) with different sensitivity to drought were exposed to 0.3 mol/L sorbitol (-1.4 MPa water potential) for 24 h. Exposure to water deficiency significantly reduced the growth of both ...Cultivars of maize (Zea mays L.) with different sensitivity to drought were exposed to 0.3 mol/L sorbitol (-1.4 MPa water potential) for 24 h. Exposure to water deficiency significantly reduced the growth of both shoots (coleoptile and hypocotyl) and roots. Shoot growth was inhibited more than the growth of roots. Osmotic stress enhanced accumulation of soluble sugars. Electrolyte leakage, a cell injury index, was slightly increased after 0.3 mol/L sorbitoh Respiration was measured in the presence and absence of 2,6-dlchloro-phenol indophenoh 2,6-Dichloro-phenol indophenol did not influence respiration rates, because statistically equal results were observed under both conditions. Total respiration (VT) decreased after osmoticum treatment. There were no significant differences in the VT among the cultlvars analysed. The decrease In VT was caused by a decline In the activities and capacities of both cytochrome (Vcyt, Vcyt) and alternative pathway (Valt, Valt) of respiration. A high residual respiration (Vres) was observed, up to 27% of total uninhibited respiration. The result of uncoupler use clearly indicated that coupling was maintained after 24 h of osmotic stress. The recovery of the respiration rate was comparable with that of non-stressed control rates. According to these observations, no possible mltochondrial damage is expected. Water deficiency did not induce a stimulation of the alternative oxidase, so we assume that the stimulation of the alternative pathway is not related to drought stress resistance; rather, the function of the alternative pathway is to balance carbon metabolism and electron transport in a response to a changing environment.展开更多
基金supported by the Key Projects in the National Science & Technology Pillar Program of China during the 11th Five-Year Plan period (2006BAD07B06)the Sci-Tech Innovation Fund for Young Scientists of Shandong Agricultural University,China (23658)
文摘Characteristics of dormancy induction and alternative respiration pathway (also known as cyanide-resistant respiration) of nectarine flower buds in different photoperiods were studied to determine the function of photoperiod and alternative respiration pathway in dormancy induction. Oxygen-electrode system and respiratory inhibitors were used to measure total respiratory rates and rates of alternative respiration pathway. The results showed that total respiration rate (Vt) in flower buds showed to be double hump-shaped curves. Short day raised, brought the first-hump of Vt forward and delayed the second-hump, while long day delayed the whole curve. The capacity (Vast) and activity (pValt) of SD and LD changed synchronously and both showed to be double hump-shaped curves. Short day made the first climax of Vast and pValt existed much earlier, while long day increased their rates significantly. The length of day had little effects on the later period climax. Long day also increased the contributions of altemative respiration pathway in total respiration rate (pValt/Vt). The changes in alternative respiration pathway were correlated with the induction of dormancy and adjusted by photoperiod. Short day promoted dormancy induction of nectarine trees, while long day delayed it.
基金the National Natural Science Foundationof China(No. 39870 0 6 4and30 0 70 0 6 5 ) partly bythe State Key Basic Research and Developm entProgram s of China(No.G19980 10 10 0 and G19990 433)
文摘Effects of inhibitors and glucose on cytochrome and alternative respiration and on adenylate energy charge (AEC) in glucose starved Chlorella protothecoides were investigated. 1 mmol/L azide (NaN 3), which immediately caused an increase of O 2 uptake by inhibiting the cytochrome pathway and stimulating alternative respiration, resulted in a decrease of AEC value from 0.83 to 0.34 within 3 minutes. When 1 mmol/L salicylhydroxamic acid (SHAM) was added into the cell suspension, there was no apparent variation in AEC. Adding NaN 3 and SHAM together into cell suspension to inhibit both cytochrome and alternative pathways showed a same change of AEC as that of adding NaN 3 alone. When 2.0 mmol/L of glucose was added to a suspension of glucose starved cells, the O 2 uptake rate was immediately stimulated from 0.81 up to 1.34 [μmol/L O 2[DK]·min -1 ·(mL PCV) -1 ]. The respiration stimulated by glucose could be inhibited about 20% by adding 1 mmol/L SHAM. It was found by titration with SHAM in the absence and presence of NaN 3 that 53% of O 2 uptake went through the cytochrome pathway and 45% of the alternate pathway was operational in enhanced respiration. It implied that induced operation of the alternative respiratory pathway probably resulted from the burst of the electron flux into the electron transport chain by glucose stimulation. . The respiration stimulated by glucose could be inhibited about 20% by adding 1 mmol/L SHAM. It was found by titration with SHAM in the absence and presence of NaN 3 that 53% of O 2 uptake went through the cytochrome pathway and 45% of the alternate pathway was operational in enhanced respiration. It implied that induced operation of the alternative respiratory pathway probably resulted from the burst of the electron flux into the electron transport chain by glucose stimulation.
基金Supported by Slovak Grant Agency for Science VEGA (2/4036/04). Publication of this paper is supported by the National Natural Science Foundation of China (30424813) and Science Publication Foundation of the Chinese Academy of Sciences,
文摘Cultivars of maize (Zea mays L.) with different sensitivity to drought were exposed to 0.3 mol/L sorbitol (-1.4 MPa water potential) for 24 h. Exposure to water deficiency significantly reduced the growth of both shoots (coleoptile and hypocotyl) and roots. Shoot growth was inhibited more than the growth of roots. Osmotic stress enhanced accumulation of soluble sugars. Electrolyte leakage, a cell injury index, was slightly increased after 0.3 mol/L sorbitoh Respiration was measured in the presence and absence of 2,6-dlchloro-phenol indophenoh 2,6-Dichloro-phenol indophenol did not influence respiration rates, because statistically equal results were observed under both conditions. Total respiration (VT) decreased after osmoticum treatment. There were no significant differences in the VT among the cultlvars analysed. The decrease In VT was caused by a decline In the activities and capacities of both cytochrome (Vcyt, Vcyt) and alternative pathway (Valt, Valt) of respiration. A high residual respiration (Vres) was observed, up to 27% of total uninhibited respiration. The result of uncoupler use clearly indicated that coupling was maintained after 24 h of osmotic stress. The recovery of the respiration rate was comparable with that of non-stressed control rates. According to these observations, no possible mltochondrial damage is expected. Water deficiency did not induce a stimulation of the alternative oxidase, so we assume that the stimulation of the alternative pathway is not related to drought stress resistance; rather, the function of the alternative pathway is to balance carbon metabolism and electron transport in a response to a changing environment.