Co-occurring increases of calcium and organellar reactive oxygen species determine differential activation of antioxidant and defense enzymes in Ulva compressa (Chlorophyta) exposed to copper excess
Co-occurring increases of calcium and organellar reactive oxygen species determine differential activation of antioxidant and defense enzymes in Ulva compressa (Chlorophyta) exposed to copper excess
复制标题
DOI：
10.1111/j.1365-3040.2010.02169.x
复制
发表时间：
2010-10-01
影响因子：
7.3
通讯作者：
Moenne, Alejandra
中科院分区：
文献类型：
--
作者：
Gonzalez, Alberto;Vera, Jeannette;Moenne, Alejandra
为了研究铜诱导的钙释放和活性氧（ROS）积累及其在抗氧化和防御酶激活中的作用，本实验以10 μ M铜处理海藻Ulva compressa 7 d，测定其钙、胞外过氧化氢（eHP）、胞内过氧化氢（iHP）和超氧阴离子（SA）水平以及抗坏血酸过氧化物酶（AP）、谷胱甘肽还原酶（GR）、谷胱甘肽s转移酶（GST）、测定苯丙氨酸解氨酶（PAL）和脂氧合酶（LOX）。钙释放呈三相模式，分别在2、3、12 h出现峰值，第2个峰与eHP和iHP的升高一致，第3个峰与iHP的升高一致。第3天后出现延迟的SA波，且不伴有钙释放。细胞器电子传递链抑制剂（OETCI）主要抑制iHP和SA的积累，而ryanodine则抑制钙的释放。使用OETCI后，AP激活几乎完全停止。另一方面，GR和GST活性受到部分抑制，而防御酶未受到抑制。ryanodine对PAL和LOX有抑制作用，而对AP无抑制作用。因此，铜胁迫诱导钙释放和细胞器ROS积累，这决定了抗氧化酶和防御酶的差异激活。
In order to analyse copper-induced calcium release and (reactive oxygen species) ROS accumulation and their role in antioxidant and defense enzymes activation, the marine alga Ulva compressa was exposed to 10 mu M copper for 7 d. The level of calcium, extracellular hydrogen peroxide (eHP), intracellular hydrogen peroxide (iHP) and superoxide anions (SA) as well as the activities of ascorbate peroxidase (AP), glutathione reductase (GR), glutathione-S-transferase (GST), phenylalanine ammonia lyase (PAL) and lipoxygenase (LOX) were determined. Calcium release showed a triphasic pattern with peaks at 2, 3 and 12 h. The second peak was coincident with increases in eHP and iHP and the third peak with the second increase of iHP. A delayed wave of SA occurred after day 3 and was not accompanied by calcium release. The accumulation of iHP and SA was mainly inhibited by organellar electron transport chains inhibitors (OETCI), whereas calcium release was inhibited by ryanodine. AP activation ceased almost completely after the use of OETCI. On the other hand, GR and GST activities were partially inhibited, whereas defense enzymes were not inhibited. In contrast, PAL and LOX were inhibited by ryanodine, whereas AP was not inhibited. Thus, copper stress induces calcium release and organellar ROS accumulation that determine the differential activation of antioxidant and defense enzymes.