Changes in main biochemical respiratory pathways in dormant nectarine floral buds were studied with nectarine trees （Prunus persica.var, nectariana cv. Shuguang） in order to determine the function of respiration in ...Changes in main biochemical respiratory pathways in dormant nectarine floral buds were studied with nectarine trees （Prunus persica.var, nectariana cv. Shuguang） in order to determine the function of respiration in dormancy release. Oxygen-electrode system and respiratory inhibitors were used to measure total respiratory rates and rates of respiratory pathways. Results showed that chilling deficiency blocked the transition of respiratory mode, and made buds stay in a state of high level pentose phosphate pathway （PPP） and low level tricarboxylie acid cycle （TCA）. The decline of PPP and activation of TCA occurred synchronously with the release of dormancy. In addition, the inhibition of PPP stimulated a respiration increase related with TCA. It could be concluded that the function of PPP activation in dormancy release might be limited and PPP declination inducing TCA activation might be part of respiration mode transition mechanism during bud sprouting.展开更多
Shuguang （Prunus persica var. nectariana cv. Shuguang） nectarine was used to study effects of photoperiod on key-enzyme activities of respiration during dormancy induction. The dormancy status was determined with sp...Shuguang （Prunus persica var. nectariana cv. Shuguang） nectarine was used to study effects of photoperiod on key-enzyme activities of respiration during dormancy induction. The dormancy status was determined with sprouting ability. Spectrophotometry was used to investigate activities of phosphohexose isomerase （PGI）, malic dehydrogenase （MDH）, and glucose-6-phosphate dehydrogenase （G6PDH）. The results revealed that short day （SD） treatment promoted dormancy induction while long day （LD） treatment postponed the process. During dormancy induction, PGI activities declined, MDH activities changed little, and G6PDH activities increased both in flower buds and leaf buds. PGI activities and MDH activities in SD treatment were lower than control, and G6PDH activities were higher, which was opposite with LD treatment. The changes of respiratory key-enzyme activities were adjusted by photoperiod and correlated with the development of dormancy induction.展开更多
High temperature stress （HT） is efficient in breaking endo-dormancy of perennial trees. The effects of HT （50°C） on the respiration of dormant nectarine （Prunus persica var. nectariana cv. Shuguang） vegetat...High temperature stress （HT） is efficient in breaking endo-dormancy of perennial trees. The effects of HT （50°C） on the respiration of dormant nectarine （Prunus persica var. nectariana cv. Shuguang） vegetative buds were evaluated in the research. We found that bud respiration was transiently inhibited by HT and the pentose phosphate pathway （PPP） and the cytochrome C pathway （CYT） were significantly affected. On the substrate level, PPP was activated in the HT-treated buds compared with the control group. However, the activation did mot occur until hours after HT treatment. The tricarboxylic acid cycle （TCA） in both the HT-treated buds and in the control group proceeded at a low level most of the time compared with total respiration. On the electron transfer level, CYT was transiently inhibited by HT but became significantly active in the later stage. CYT operation in the control group exhibited an attenuation process. The alternative pathway （ALT） fluctuated both in the HT-treated samples and in the control. The results suggest that the temporary CYT inhibition and the following PPP activation may be involved in HT-induced bud dormancy release and budburst mechanisms.展开更多
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
Operation regulations of two main electron transport pathways in nectarine （Prunus persica var. nectariana cv. Shuguang） buds during endodormancy induction were studied to understand possible roles which two main el...Operation regulations of two main electron transport pathways in nectarine （Prunus persica var. nectariana cv. Shuguang） buds during endodormancy induction were studied to understand possible roles which two main electron transport pathways played in the buds of deciduous fruit trees during endodormancy induction. Respiratory inhibitors （KCN and SHAM） were used to investigate total respiration rate （Vt）, the development and operation of the alternative pathway and partitioning of electrons between the cytochrome and alternative pathways in nectarine buds during endodormancy induction. Results indicated that changes of Vt in flower and leaf buds showed single and double hump-shaped curves, respectively. In endodormancy induction, the capacity （Valt,） and activity （ρValt） of the alternative pathway rapidly increased, but changes of them had different patterns during the entire measuration. At the same time, changes of engagements of the alternative （ρValt/Vt） and cytochrome pathway （ρ′Vcyt/Vt） were opposite, and ρ′Vcyt/Vt was always further higher than ρValt/Vt during the entire measuration. All these results indicated that the development and operation of the alternative pathway played important roles in endodormancy induction, but the cytochrome pathway was the main pathway for mitochondrial electron transport in buds during endodormancy induction.展开更多
基金supported by the National 863 Program of China(2005AA247041)Key Projects in the National Science and Technology Pillar Program during the 11th Five-Year Plan period,China(2006BAD07B06)
文摘Changes in main biochemical respiratory pathways in dormant nectarine floral buds were studied with nectarine trees （Prunus persica.var, nectariana cv. Shuguang） in order to determine the function of respiration in dormancy release. Oxygen-electrode system and respiratory inhibitors were used to measure total respiratory rates and rates of respiratory pathways. Results showed that chilling deficiency blocked the transition of respiratory mode, and made buds stay in a state of high level pentose phosphate pathway （PPP） and low level tricarboxylie acid cycle （TCA）. The decline of PPP and activation of TCA occurred synchronously with the release of dormancy. In addition, the inhibition of PPP stimulated a respiration increase related with TCA. It could be concluded that the function of PPP activation in dormancy release might be limited and PPP declination inducing TCA activation might be part of respiration mode transition mechanism during bud sprouting.
基金supported by the National High-Tech R&D Program (863) of China (2005AA247041)the Key Projects in the National Science & Technology Pillar Program of China during the 11th Five-Year Plan period (2006BAD07B06)
文摘Shuguang （Prunus persica var. nectariana cv. Shuguang） nectarine was used to study effects of photoperiod on key-enzyme activities of respiration during dormancy induction. The dormancy status was determined with sprouting ability. Spectrophotometry was used to investigate activities of phosphohexose isomerase （PGI）, malic dehydrogenase （MDH）, and glucose-6-phosphate dehydrogenase （G6PDH）. The results revealed that short day （SD） treatment promoted dormancy induction while long day （LD） treatment postponed the process. During dormancy induction, PGI activities declined, MDH activities changed little, and G6PDH activities increased both in flower buds and leaf buds. PGI activities and MDH activities in SD treatment were lower than control, and G6PDH activities were higher, which was opposite with LD treatment. The changes of respiratory key-enzyme activities were adjusted by photoperiod and correlated with the development of dormancy induction.
基金supported by the the Key Technologies R&D Program of China during the 12th Five-Year Plan period (2011BAD12B02)
文摘High temperature stress （HT） is efficient in breaking endo-dormancy of perennial trees. The effects of HT （50°C） on the respiration of dormant nectarine （Prunus persica var. nectariana cv. Shuguang） vegetative buds were evaluated in the research. We found that bud respiration was transiently inhibited by HT and the pentose phosphate pathway （PPP） and the cytochrome C pathway （CYT） were significantly affected. On the substrate level, PPP was activated in the HT-treated buds compared with the control group. However, the activation did mot occur until hours after HT treatment. The tricarboxylic acid cycle （TCA） in both the HT-treated buds and in the control group proceeded at a low level most of the time compared with total respiration. On the electron transfer level, CYT was transiently inhibited by HT but became significantly active in the later stage. CYT operation in the control group exhibited an attenuation process. The alternative pathway （ALT） fluctuated both in the HT-treated samples and in the control. The results suggest that the temporary CYT inhibition and the following PPP activation may be involved in HT-induced bud dormancy release and budburst mechanisms.
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.
文摘Operation regulations of two main electron transport pathways in nectarine （Prunus persica var. nectariana cv. Shuguang） buds during endodormancy induction were studied to understand possible roles which two main electron transport pathways played in the buds of deciduous fruit trees during endodormancy induction. Respiratory inhibitors （KCN and SHAM） were used to investigate total respiration rate （Vt）, the development and operation of the alternative pathway and partitioning of electrons between the cytochrome and alternative pathways in nectarine buds during endodormancy induction. Results indicated that changes of Vt in flower and leaf buds showed single and double hump-shaped curves, respectively. In endodormancy induction, the capacity （Valt,） and activity （ρValt） of the alternative pathway rapidly increased, but changes of them had different patterns during the entire measuration. At the same time, changes of engagements of the alternative （ρValt/Vt） and cytochrome pathway （ρ′Vcyt/Vt） were opposite, and ρ′Vcyt/Vt was always further higher than ρValt/Vt during the entire measuration. All these results indicated that the development and operation of the alternative pathway played important roles in endodormancy induction, but the cytochrome pathway was the main pathway for mitochondrial electron transport in buds during endodormancy induction.
