This research was to examine if rice (Oryza sativa L.), a monocotyledon of angiosperm, was able to synthesize chlorophyll (Chl) in complete darkness. Five-cm-tall etiolated seedlings of rice were used as starting mate...This research was to examine if rice (Oryza sativa L.), a monocotyledon of angiosperm, was able to synthesize chlorophyll (Chl) in complete darkness. Five-cm-tall etiolated seedlings of rice were used as starting materials and treated with or without various concentrations of glucose and/or δ-aminolevulinic acid (ALA) in the dark. Leaves harvested at the indicated time were determined for their contents of Chl, protoporphyrin Ⅸ (Proto), Mg-protoporphyrin Ⅸ (Mg-Proto) and protochlorophyllide (Pchlide). The mole percentage of porphyrin was calculated. The Chl content in the etiolated rice seedlings slightly increased from about 2.5 μg/g to 7.5 μg/g within 12 d in the dark, but the total Chl of dark-grown rice increased from 0.36 μg/g to 3.6 μg/g. While the mole percentages of Proto, Mg-Proto and Pchlide in the dark-grown seedlings without any treatment were about 65%, 27.5% and 7.5% at the beginning, respectively, those in the light-grown seedlings were about 42.5%, 35% and 22.5%, respectively. The mole percentage of porphyrin of etiolated seedlings resumed its normal ratio within 2 d after treatment with glucose. While the Chl content of etiolated seedlings grown in culture solution with 3% and 6% glucose increased 2.5 and 4.0 folds, respectively, those with 3% and 6% glucose and 1 mmol/L ALA increased 22 and 24 folds, respectively. It is concluded that angiosperm might be able to synthesize a small amount of Chl in complete darkness, that either glucose or ALA could stimulate dark Chl synthesis in angiosperm, and that a combination of glucose and ALA exhibited an additional effect. It is still unknown and remains to be further explored what is the mechanism of the effect of glucose and ALA on the Chl synthesis of rice in the dark.展开更多
目的观察激光光源和LED光源激发原卟啉Ⅸ(ProtoporphyrinⅨ,PpⅨ)产生的单线态氧产量,在溶液体系评价两种光源的对PpⅨ介导的光动力效应。方法利用单线态氧特异的商业化荧光探针定量检测激光和LED辐照PpⅨ产生的单线态氧产量,比较两种...目的观察激光光源和LED光源激发原卟啉Ⅸ(ProtoporphyrinⅨ,PpⅨ)产生的单线态氧产量,在溶液体系评价两种光源的对PpⅨ介导的光动力效应。方法利用单线态氧特异的商业化荧光探针定量检测激光和LED辐照PpⅨ产生的单线态氧产量,比较两种光源激发产生的单线态氧产量比值。结果在17.68 m W/cm2、35.37 m W/cm2、70.74 m W/cm2三档不同的功率密度下,激光与LED辐照PpⅨ产生的单线态氧比值均约等于1,两种光源相同功率密度条件下的单线态氧比值无显著统计学差异。结论在相同的功率密度下,635 nm激光和633 nm LED激光在溶液体系中经PpⅨ-PDT单线态氧产量比值是相等的,而细胞和生物组织中的PDT效应还有待于进一步探索。展开更多
文摘This research was to examine if rice (Oryza sativa L.), a monocotyledon of angiosperm, was able to synthesize chlorophyll (Chl) in complete darkness. Five-cm-tall etiolated seedlings of rice were used as starting materials and treated with or without various concentrations of glucose and/or δ-aminolevulinic acid (ALA) in the dark. Leaves harvested at the indicated time were determined for their contents of Chl, protoporphyrin Ⅸ (Proto), Mg-protoporphyrin Ⅸ (Mg-Proto) and protochlorophyllide (Pchlide). The mole percentage of porphyrin was calculated. The Chl content in the etiolated rice seedlings slightly increased from about 2.5 μg/g to 7.5 μg/g within 12 d in the dark, but the total Chl of dark-grown rice increased from 0.36 μg/g to 3.6 μg/g. While the mole percentages of Proto, Mg-Proto and Pchlide in the dark-grown seedlings without any treatment were about 65%, 27.5% and 7.5% at the beginning, respectively, those in the light-grown seedlings were about 42.5%, 35% and 22.5%, respectively. The mole percentage of porphyrin of etiolated seedlings resumed its normal ratio within 2 d after treatment with glucose. While the Chl content of etiolated seedlings grown in culture solution with 3% and 6% glucose increased 2.5 and 4.0 folds, respectively, those with 3% and 6% glucose and 1 mmol/L ALA increased 22 and 24 folds, respectively. It is concluded that angiosperm might be able to synthesize a small amount of Chl in complete darkness, that either glucose or ALA could stimulate dark Chl synthesis in angiosperm, and that a combination of glucose and ALA exhibited an additional effect. It is still unknown and remains to be further explored what is the mechanism of the effect of glucose and ALA on the Chl synthesis of rice in the dark.
文摘目的观察激光光源和LED光源激发原卟啉Ⅸ(ProtoporphyrinⅨ,PpⅨ)产生的单线态氧产量,在溶液体系评价两种光源的对PpⅨ介导的光动力效应。方法利用单线态氧特异的商业化荧光探针定量检测激光和LED辐照PpⅨ产生的单线态氧产量,比较两种光源激发产生的单线态氧产量比值。结果在17.68 m W/cm2、35.37 m W/cm2、70.74 m W/cm2三档不同的功率密度下,激光与LED辐照PpⅨ产生的单线态氧比值均约等于1,两种光源相同功率密度条件下的单线态氧比值无显著统计学差异。结论在相同的功率密度下,635 nm激光和633 nm LED激光在溶液体系中经PpⅨ-PDT单线态氧产量比值是相等的,而细胞和生物组织中的PDT效应还有待于进一步探索。
