Group of Antioxidants, Free Radicals and Nitric Oxide in Biotechnology, Food and Agriculture, Department of Biochemistry, Cell and Molecular Biology of Plants, Estación Experimental del Zaidín, Spanish National Research Council (CSIC), Apartado 419, E-18080 Granada, Spain; Plant Toxicology and Molecular Biology of Microorganisms, Faculty of Sciences of Bizerta (Carthage University), 7021 Zarzouna, Tunisia.
Group of Antioxidants, Free Radicals and Nitric Oxide in Biotechnology, Food and Agriculture, Department of Biochemistry, Cell and Molecular Biology of Plants, Estación Experimental del Zaidín, Spanish National Research Council (CSIC), Apartado 419, E-18080 Granada, Spain; Laboratory of Extremophile Plants, Center of Biotechnology of Borj Cedria, PO Box 901, 2050 Hammam-Lif, Tunisia.
J Plant Physiol. 2017 Dec;219:71-80. doi: 10.1016/j.jplph.2017.09.010. Epub 2017 Oct 10.
Chromium (Cr) contamination in soil is a growing concern in relation to sustainable agricultural production and food safety. Nitric oxide (NO) and, more recently, hydrogen sulfide (HS) are considered to be new signalling molecules with biotechnological applications in the agronomical sector. Using 9-day-old maize (Zea mays) seedlings exposed to 200μM Cr(VI), the potential mitigating effects of exogenous NO and HS on chromium-induced stress in maize seedlings were investigated in roots, cotyledons and coleoptiles. Analysis of Cr content, lipid peroxidation, antioxidant enzymes (catalase and superoxide dismutase isozymes), peroxisomal HO-producing glycolate oxidase and the main NADPH-regenerating system revealed that chromium causes oxidative stress, leading to a general increase in these activities in coleptiles and roots, with the latter organ being the most affected. However, cotyledons behaved in an opposite manner. Moreover, exogenous applications of NO and HS to Cr-stressed maize seedlings triggered a significant response, involving the virtual restoration of the values for all these activities to those observed in unstressed seedlings, although their specific impact on ROS and NADPH-recycling metabolisms depends on the seedling organ involved. Taken together, the data indicate that gas transmitters, NO and HS, which act as a defence against the negative effects of hexavalent chromium contamination, are alternative compounds with potential biotechnological applications.
土壤中的铬污染与可持续农业生产和食品安全息息相关，这是一个日益受到关注的问题。一氧化氮（NO）和最近的硫化氢（HS）被认为是具有生物技术应用潜力的新信号分子，在农业领域有应用前景。本研究使用 9 天大的玉米（Zea mays）幼苗作为实验材料，在 200μM Cr(VI) 胁迫下，研究了外源 NO 和 HS 对玉米幼苗根部、子叶和胚芽中 Cr 诱导胁迫的缓解作用。通过分析 Cr 含量、脂质过氧化、抗氧化酶（过氧化氢酶和超氧化物歧化酶同工酶）、过氧化物酶体 HO 生成的甘油酸氧化酶和主要的 NADPH 再生系统，结果表明 Cr 会引起氧化应激，导致 coleoptile 和根中这些酶活性普遍增加，其中根器官受影响最大。然而，子叶的表现则相反。此外，外源施加 NO 和 HS 可触发 Cr 胁迫下玉米幼苗的显著响应，涉及所有这些酶活性值恢复到未胁迫幼苗的水平，尽管它们对 ROS 和 NADPH 循环代谢的具体影响取决于所涉及的幼苗器官。综上所述，这些数据表明，气体信号分子 NO 和 HS 可作为抵御六价铬污染负面影响的防御机制，是具有潜在生物技术应用前景的替代化合物。
