Effect of ascorbate and its oxidation products on H2O2 production in cell-suspension cultures of Picea abies and in the absence of cells
Effect of ascorbate and its oxidation products on H2O2 production in cell-suspension cultures of Picea abies and in the absence of cells
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DOI：
10.1093/jxb/erj197
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发表时间：
2006-01-01
影响因子：
6.9
通讯作者：
Fry, Stephen C.
中科院分区：
文献类型：
--
作者：
Karkonen, Anna;Fry, Stephen C.
脱氢抗坏血酸和微量的抗坏血酸存在于活体云杉（云杉）枝条中。由于所提出的质外体抗坏血酸降解途径包含可能产生H2 O2的几个步骤，因此测试了抗坏血酸及其一些降解产物对作为模型的P. abies细胞培养物中质外体H2 O2浓度的影响以及对体外非酶H2 O2产生的影响。抗坏血酸清除H2 O2在培养基中的木质素生产云杉细胞和用过的和煮沸的培养基中;在存在的Cu 2+或新鲜培养基中，抗坏血酸导致非酶生成H2 O2。脱氢抗坏血酸（抗坏血酸的初始氧化产物）和diketogulonate（脱氢抗坏血酸的水解产物）的制剂诱导H2 O2积累的非酶和酶在云杉细胞悬浮液。纸电泳表明，脱氢抗坏血酸和diketogulonate制剂含有几种降解产物，其中一些可能有助于过氧化氢的生产和/或清除在这些实验中，也会这样做在体内。这些结果表明，质外体抗坏血酸，脱氢抗坏血酸，diketogulonate，和进一步的产品，以调节过氧化氢浓度的复杂能力，与控制的生长，发育和木质化的潜在后果。
Dehydroascorbate and traces of ascorbate were present apoplastically in living spruce (Picea abies) twigs. Since the proposed apoplastic ascorbate degradation pathway contains several steps that possibly generate H2O2, the effects of ascorbate and some of its degradation products were tested on apoplastic H2O2 concentrations in a cell culture of P. abies as a model and on non-enzymic H2O2 production in vitro. Ascorbate scavenged H2O2 in the culture medium of lignin-producing Picea cells and in spent and boiled spent medium; in the presence of Cu2+ or fresh medium, ascorbate led to the non-enzymic generation of H2O2. Preparations of dehydroascorbate (the initial oxidation-product of ascorbate), and diketogulonate (the hydrolysis-product of dehydroascorbate) induced H2O2 accumulation both non-enzymically and enzymically in Picea cell-suspensions. Paper electrophoresis showed that the dehydroascorbate and diketogulonate preparations contained several degradation products; some of these probably contributed to H2O2 production and/or scavenging in these experiments, and would also do so in vivo. These results indicate a complex ability of apoplastic ascorbate, dehydroascorbate, diketogulonate, and further products to modulate H2O2 concentrations, with potential consequences for the control of growth, development and lignification.