Molnár Árpád, Feigl Gábor, Trifán Vanda, Ördög Attila, Szőllősi Réka, Erdei László, Kolbert Zsuzsanna
Department of Plant Biology, University of Szeged, Közép fasor 52, H-6726 Szeged, Hungary.
Ecotoxicol Environ Saf. 2018 Jan;147:93-101. doi: 10.1016/j.ecoenv.2017.08.038. Epub 2017 Sep 14.
Selenium phytotoxicity involves processes like reactive nitrogen species overproduction and nitrosative protein modifications. This study evaluates the toxicity of two selenium forms (selenite and selenate at 0µM, 20µM, 50µM and 100µM concentrations) and its correlation with protein tyrosine nitration in the organs of hydroponically grown Indian mustard (Brassica juncea L.). Selenate treatment resulted in large selenium accumulation in both Brassica organs, while selenite showed slight root-to-shoot translocation resulting in a much lower selenium accumulation in the shoot. Shoot and root growth inhibition and cell viability loss revealed that Brassica tolerates selenate better than selenite. Results also show that relative high amounts of selenium are able to accumulate in Brassica leaves without obvious visible symptoms such as chlorosis or necrosis. The more severe phytotoxicity of selenite was accompanied by more intense protein tyrosine nitration as well as alterations in nitration pattern suggesting a correlation between the degree of Se forms-induced toxicities and nitroproteome size, composition in Brassica organs. These results imply the possibility of considering protein tyrosine nitration as novel biomarker of selenium phytotoxicity, which could help the evaluation of asymptomatic selenium stress of plants.
硒的植物毒性涉及活性氮物种过量产生和蛋白质亚硝化修饰等过程。本研究评估了两种硒形态（亚硒酸盐和硒酸盐，浓度分别为0µM、20µM、50µM和100µM）的毒性及其与水培印度芥菜（Brassica juncea L.）器官中蛋白质酪氨酸硝化的相关性。硒酸盐处理导致两种芥菜器官中大量积累硒，而亚硒酸盐显示出从根到地上部的轻微转运，导致地上部的硒积累量低得多。地上部和根的生长抑制以及细胞活力丧失表明，芥菜对硒酸盐的耐受性优于亚硒酸盐。结果还表明，相对大量的硒能够在芥菜叶片中积累，而没有明显的可见症状，如黄化或坏死。亚硒酸盐更严重的植物毒性伴随着更强烈的蛋白质酪氨酸硝化以及硝化模式的改变，这表明硒形态诱导的毒性程度与芥菜器官中的硝基蛋白质组大小、组成之间存在相关性。这些结果暗示了将蛋白质酪氨酸硝化作为硒植物毒性新生物标志物的可能性，这有助于评估植物无症状的硒胁迫。
