Borges Karina Lima Reis, Salvato Fernanda, Alcântara Berenice Kussumoto, Nalin Rafael Storto, Piotto Fernando Ângelo, Azevedo Ricardo Antunes
Laboratory of Plant Genetics and Biochemistry, Genetics Department, "Luiz de Queiroz" College of Agriculture, Piracicaba, SP, Brazil.
Laboratory of Molecular Physiology of Plants, Institute of Biology, State University of Campinas, Campinas, SP, Brazil.
Ecotoxicology. 2018 Apr;27(3):245-258. doi: 10.1007/s10646-017-1889-x. Epub 2018 Jan 2.
Despite numerous studies on cadmium (Cd) uptake and accumulation in crops, relatively little is available considering the temporal dynamic of Cd uptake and responses to stress focused on the root system. Here we highlighted the responses to Cd-induced stress in roots of two tomato genotypes contrasting in Cd-tolerance: the tolerant Pusa Ruby and the sensitive Calabash Rouge. Tomato genotypes growing in the presence of 35 μM CdCl exhibited a similar trend of Cd accumulation in tissues, mainly in the root system and overall plants exhibited reduction in the dry matter weight. Both genotypes showed similar trends for malondialdehyde and hydrogen peroxide accumulation with increases when exposed to Cd, being this response more pronounced in the sensitive genotype. When the antioxidant machinery is concerned, in the presence of Cd the reduced glutathione content was decreased in roots while ascorbate peroxidase (APX), glutathione reductase (GR) and glutathione S-transferase (GST) activities were increased in the presence of Cd in the tolerant genotype. Altogether these results suggest APX, GR and GST as the main players of the antioxidant machinery against Cd-induced oxidative stress.
尽管针对作物中镉（Cd）的吸收和积累已有大量研究，但关于镉吸收的时间动态以及根系对胁迫的响应的研究相对较少。在此，我们着重研究了两种对镉耐受性不同的番茄基因型根系对镉诱导胁迫的响应：耐受性较强的Pusa Ruby和敏感性较强的Calabash Rouge。在35 μM CdCl存在的情况下生长的番茄基因型，其组织中镉积累呈现相似趋势，主要集中在根系，且整株植物的干物质重量均有所降低。两种基因型在丙二醛和过氧化氢积累方面表现出相似趋势，暴露于镉时均增加，且这种响应在敏感基因型中更为明显。就抗氧化机制而言，在镉存在的情况下，耐受性基因型根系中还原型谷胱甘肽含量降低，而抗坏血酸过氧化物酶（APX）、谷胱甘肽还原酶（GR）和谷胱甘肽S - 转移酶（GST）的活性增加。这些结果共同表明，APX、GR和GST是对抗镉诱导氧化胁迫的抗氧化机制的主要参与者。
