Early activation of lipoxygenase in lentil (Lens culinaris) root protoplasts by oxidative stress induces programmed cell death
Early activation of lipoxygenase in lentil (Lens culinaris) root protoplasts by oxidative stress induces programmed cell death
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DOI：
10.1046/j.1432-1327.2000.01564.x
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发表时间：
2000-08-01
期刊：
影响因子：
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通讯作者：
Finazzi-Agrò, A
中科院分区：
文献类型：
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作者：
Maccarrone, M;Van Zadelhoff, G;Finazzi-Agrò, A
过氧化氢(H_2O_2)引起的氧化胁迫触发植物对病原体的超敏反应。图中显示，短脉冲的双氧水会导致小扁豆(Lens Culinaris)根部原生质体死亡。死亡细胞出现DNA片段化和梯形，这是细胞凋亡(程序性细胞死亡)的典型特征。H_2O_2脉冲作用12h后DNA损伤明显，12h后达到最大。细胞对H_2O_2诱导的细胞凋亡的参与表现为脂氧合酶活性、超弱发光和膜脂过氧化作用的早期增加，在H_2O_2处理后6h分别达到对照组的720%、350%和300%。脂氧合酶活性的增加与其蛋白和mRNA水平的增加是平行的。脂肪氧合酶抑制剂去甲二氢愈创木酸、二十碳四烯酸和抗坏血酸可阻止过氧化氢诱导的DNA断裂和超微弱发光，仅当与过氧化氢一起使用时，而在8h后加入则不能。通过电穿孔将抑制性抗脂氧合酶单抗导入原生质体，保护细胞免受过氧化氢诱导的细胞凋亡。另一方面，小扁豆脂肪氧合酶产物9-和13-羟基过氧基十八碳二烯酸及其还原醇衍生物能够迫使原生质体发生凋亡。总之，这些发现表明，脂氧合酶的早期激活是执行氧化应激诱导植物细胞凋亡的关键因素，其方式与在动物细胞中观察到的方式惊人地相似。
Oxidative stress caused by hydrogen peroxide (H2O2) triggers the hypersensitive response of plants to pathogens. Here, short pulses of H2O2 are shown to cause death of lentil (Lens culinaris) root protoplasts. Dead cells showed DNA fragmentation and ladder formation, typical hallmarks of apoptosis (programmed cell death). DNA damage was evident 12 h after the H2O2 pulse and reached a maximum 12 h later. The commitment of cells to apoptosis caused by H2O2 was characterized by an early increase of lipoxygenase activity, of ultraweak luminescence and of membrane lipid peroxidation, which reached 720, 350 and 300% of controls, respectively, at 6 h after H2O2 treatment. Increased lipoxygenase activity was paralleled by an increase of its protein and mRNA level. Lipoxygenase inhibitors nordihydroguaiaretic acid, eicosatetraynoic acid and plamitoyl ascorbate prevented H2O2-induced DNA fragmentation and ultraweak luminescence, only when added together with H2O2, but not when added 8 h afterwards. Inhibitory anti-lipoxygenase monoclonal antibodies, introduced into the protoplasts by electroporation, protected cells against H2O2-induced apoptosis. On the other hand, lentil lipoxygenase products 9- and 13-hydroperoxy-octadecadienoic acids and their reduced alcohol derivatives were able to force the protoplasts into apoptosis. Altogether, these findings suggest that early activation of lipoxygenase is a key element in the execution of apoptosis induced by oxidative stress in plant cells, in a way surprisingly similar to that observed in animal cells.