College of Environmental Science & Engineering, Guilin University of Technology, Guilin 541004, People's Republic of China.
College of Environmental Science & Engineering, Guilin University of Technology, Guilin 541004, People's Republic of China.
Sci Total Environ. 2020 Nov 20;744:140951. doi: 10.1016/j.scitotenv.2020.140951. Epub 2020 Jul 15.
Plants possess a well-organized protective network, wherein antioxidant enzymes play an important part in dealing with oxidative stress induced by over accumulation of ROS in plant cells. In the present study, a microcosm hydroponic experiment was performed to investigate the molecular modification of antioxidant enzymes at subcellular levels in rice seedlings in the presence of either trivalent [Cr(III)] or hexavalent chromium [Cr(VI)] using rice oligonucleotide microarray analysis. The results indicated that the production of ROS induced by Cr(III, VI) was concentration-dependent, Cr-specific and tissue-specific. Trivalent or hexavalent chromium exposure significantly (p < 0.05) altered the antioxidant enzymes activities in both rice tissues in comparison to control plants. In total, 41 genes were identified from the data of rice oligonucleotide microarray analysis. Under Cr(III) exposure, relatively higher expression of genes was observed in roots compared to those in shoots (p < 0.05), while gene expressions in both plant parts differed slightly during Cr(VI) exposure, implying different regulation and response strategies of plants against Cr(III) and Cr(VI). Subcellular localization indicated that genes encoding SOD, POD, APX, and GPX are mainly prevalent in the cytoplasm (30.77%), chloroplasts (29.23%), peroxisomes (10.77%) and mitochondria (9.23%), suggesting that cytoplasm and chloroplasts are the main sites responsible for scavenging ROS through enzymatic processes. Our study provides new insight into the roles of antioxidant enzymes in ROS metabolism at subcellular levels under Cr exposure.
植物拥有一个组织良好的保护网络，其中抗氧化酶在应对植物细胞中 ROS 过度积累引起的氧化应激方面起着重要作用。本研究采用水稻寡核苷酸微阵列分析，在水稻幼苗的微宇宙水培实验中，研究了三价[Cr(III)]或六价铬[Cr(VI)]存在下，亚细胞水平抗氧化酶的分子修饰。结果表明，Cr(III, VI)诱导的 ROS 产生具有浓度依赖性、Cr 特异性和组织特异性。与对照植物相比，三价或六价铬暴露显著（p < 0.05）改变了两种水稻组织中抗氧化酶的活性。总共从水稻寡核苷酸微阵列分析的数据中鉴定出 41 个基因。在 Cr(III)暴露下，与叶片相比，根中观察到相对较高的基因表达（p < 0.05），而在 Cr(VI)暴露下，两个植物部分的基因表达略有差异，表明植物对 Cr(III)和 Cr(VI)的不同调控和响应策略。亚细胞定位表明，编码 SOD、POD、APX 和 GPX 的基因主要存在于细胞质（30.77%）、叶绿体（29.23%）、过氧化物酶体（10.77%）和线粒体（9.23%）中，表明细胞质和叶绿体是通过酶促过程清除 ROS 的主要部位。我们的研究为 Cr 暴露下抗氧化酶在 ROS 代谢中的亚细胞水平作用提供了新的见解。
