The sectioned thin cell layers (TCL) of flower stalk of Cichorium intybus L. were cultured in MS medium supplemented with NAA and BA or IAA and BA where floral and vegetative buds were developed from the explant. ...The sectioned thin cell layers (TCL) of flower stalk of Cichorium intybus L. were cultured in MS medium supplemented with NAA and BA or IAA and BA where floral and vegetative buds were developed from the explant. Endogenous IAA, DHZ+DHZR, iPA increased significantly during the floral bud formation, while Z+ZR remained changed. The levels of cytokinins, DHZ+DHZR, iPA, and Z+ZR all increased significantly during the vegetative bud formation, however IAA level was reduced during the first 7 days of culture and increased to two thirds of initial values on the day when the bud primordia were formed. The results suggested that the initiation of floral buds was associated with a high IAA/CTK ratio, whereas the induction of vegetative bud differentiation was related to a low IAA/CTK ratio.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
文摘The sectioned thin cell layers (TCL) of flower stalk of Cichorium intybus L. were cultured in MS medium supplemented with NAA and BA or IAA and BA where floral and vegetative buds were developed from the explant. Endogenous IAA, DHZ+DHZR, iPA increased significantly during the floral bud formation, while Z+ZR remained changed. The levels of cytokinins, DHZ+DHZR, iPA, and Z+ZR all increased significantly during the vegetative bud formation, however IAA level was reduced during the first 7 days of culture and increased to two thirds of initial values on the day when the bud primordia were formed. The results suggested that the initiation of floral buds was associated with a high IAA/CTK ratio, whereas the induction of vegetative bud differentiation was related to a low IAA/CTK ratio.
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.
