Production of reactive oxygen species, impairment of photosynthetic function and dynamic changes in mitochondria are early events in cadmium-induced cell death in Arabidopsis thaliana
Production of reactive oxygen species, impairment of photosynthetic function and dynamic changes in mitochondria are early events in cadmium-induced cell death in Arabidopsis thaliana
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DOI：
10.1042/bc20090015
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发表时间：
2009-11-01
影响因子：
2.7
通讯作者：
Xing, Da
中科院分区：
文献类型：
--
作者：
Bi, YuHua;Chen, WenLi;Xing, Da
背景资料。镉（Cd）是一种毒性很强的重金属，它通过抑制植物的光合作用和呼吸作用而引起植物代谢的改变。在单细胞水平上研究了镉对拟南芥叶绿体和线粒体的形态和功能以及活性氧（ROS）的产生和定位的影响。结果表明，镉处理后，叶绿体的形态发生了变化，在叶绿体形态发生明显畸变之前，光化学效率急剧下降。镉处理后，检测到一个快速爆发的活性氧。ROS首先出现在线粒体中，随后出现在叶绿体中。同时，线粒体不规则地聚集在叶绿体周围或聚集在细胞质中，线粒体的运动也随之受阻。此外，活性氧的产生减少后，用抗坏血酸或过氧化氢酶预处理，防止光合作用的抑制，细胞器的变化和随后的原生质体死亡。结果表明，线粒体的分布和运动，叶绿体的形态和ROS的积累在镉诱导的细胞死亡中起重要作用。这一结果与以前报道的多种类型的类凋亡细胞死亡的结果一致。线粒体的分布和运动性、叶绿体形态的改变以及活性氧的积累在镉诱导的细胞死亡中起重要作用。
Background information. Cadmium (Cd) is a highly toxic heavy metal that causes changes in plant metabolism through inhibiting photosynthesis and respiration. The effects of Cd on the morphology and function of the chloroplast and mitochondria, as well as on the production and localization of ROS (reactive oxygen species), were studied at the single-cell level in Arabidopsis.Results. The present study showed that the morphology of chloroplasts changed after Cd treatment, and the photochemical efficiency dramatically declined prior to obvious morphological distortion in the chloroplasts. A quick burst of ROS was detected after Cd treatment. The ROS appeared first in the mitochondria and subsequently in the chloroplast. Simultaneously, the mitochondria clumped irregularly around the chloroplasts or aggregated in the cytoplasm, and the movement of mitochondria was concomitantly blocked. Furthermore, the production of ROS was decreased after pre-treatment with ascorbic acid or catalase, which prevented inhibition of photosynthesis, organelle changes and subsequent protoplast death. Our results suggest that the distribution and mobility of mitochondria, the morphology of chloroplasts and the accumulation of ROS play important roles in Cd-induced cell death. The results are in good agreement with previous reports of many types of apoptotic-like cell death.Conclusion. The changes in the distribution and mobility of mitochondria, and morphology of chloroplasts, as well as the accumulation of ROS, play important roles in Cd-induced cell death.