Mitigation of osmotic and salt stresses by abscisic acid through reduction of stress-derived oxidative damage in Chlamydomonas reinhardtii
Mitigation of osmotic and salt stresses by abscisic acid through reduction of stress-derived oxidative damage in Chlamydomonas reinhardtii
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DOI：
10.1016/j.plantsci.2004.07.002
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发表时间：
2004-12
期刊：
影响因子：
5.2
通讯作者：
Kenji Yoshida;E. Igarashi;Eiko Wakatsuki;K. Miyamoto;K. Hirata
中科院分区：
文献类型：
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作者：
Kenji Yoshida;E. Igarashi;Eiko Wakatsuki;K. Miyamoto;K. Hirata
在莱茵衣藻中，外加脱落酸(ABA)部分释放了山梨醇渗透胁迫和氯化钠盐胁迫造成的生长抑制，与百草枯在前期研究中所做的相同。然而，在用ABA处理24小时的细胞中，与未处理的细胞相比，短期暴露于这些水分胁迫所造成的损害并没有减少。应激暴露的细胞内ROS水平显著高于非应激暴露的细胞。ABA处理显著降低了这种ROS的产生，增强了抗氧化酶过氧化氢酶(CAT)和抗坏血酸过氧化物酶(APX)的基因表达，而不是提高了这些酶的活性。这些结果表明，ABA可能只诱导减少渗透胁迫和盐胁迫引起的氧化损伤的反应，但不能诱导任何特定的反应来减少这些水分胁迫直接造成的伤害。ABA可能通过消除ROS来减轻氧化损伤，从而可能导致上述生长抑制的释放。
In the green alga, Chlamydomonas reinhardtii, externally added abscisic acid (ABA) partly released the growth suppression caused by osmotic stress with sorbitol and salt stress with NaCl, in the same way that paraquat did in a previous study. In cells treated with ABA for 24h, however, the damage caused by a short-period exposure to these water stresses was not reduced in comparison with non-treated cells. Intracellular levels of reactive oxygen species (ROS) in stress-exposed cells were significantly higher than in non-stress-exposed cells. ABA treatment markedly reduced this ROS generation and enhanced gene expression of the antioxidant enzymes, catalase (CAT) and ascorbate peroxidase (APX), in preference to increasing the activities of these enzymes. These results suggest that ABA might only induce response reactions which reduce the oxidative damage derived from exposure to osmotic and salt stresses in C. reinhardtii, but did not act to induce any specific reactions to reduce the damage caused directly by these water stresses. This mitigation of oxidative damage by ABA, probably by the elimination of ROS, might result in the above-mentioned release of growth suppression.