Department of Biological Sciences, Michigan Technological University, Houghton, MI, USA.
School of Medicine, University of California, San Diego, CA, USA.
Chemosphere. 2020 Feb;240:124961. doi: 10.1016/j.chemosphere.2019.124961. Epub 2019 Sep 24.
Acid mine drainage (AMD) is a sulfuric discharge containing metals and particulates that can spread to nearby water sources, imposing toxicity and physical stress to living things. We have shown that vetiver grass (Chrysopogon zizanioides) is capable of tolerating and treating AMD-impacted water from the abandoned Tab-Simco mining site from southern Illinois, though little is known about its tolerance mechanisms. We conducted metabolomic analyses of vetiver shoots and roots after relatively short- and long-term periods of exposure to Tab-Simco AMD. The metabolic shift of vetiver shoots was dramatic with longer-term AMD exposure, including upregulation of amino acid and glutathione metabolism, cellular respiration and photosynthesis pathways, with downregulation of phosphorylated metabolites. Meanwhile, the roots demonstrated drastic downregulation of phospholipids and phosphorylated metabolites, cellular respiration, glyoxylate metabolism, and amino acid metabolism. Vetiver accumulated ornithine and oxaloacetate in the shoots, which could function for nitrogen storage and various intracellular functions, respectively. Organic acids and glutathione were secreted from the roots for rhizospheric metal-chelation, whereas phosphorylated metabolites were recycled for phosphorus. These findings reveal AMD-induced metabolic shifts in vetiver grass, which are seemingly unique in comparison to independent abiotic stresses reported previously.
酸性矿山排水 (AMD) 是一种含有金属和颗粒物的硫酸排放物，可扩散到附近的水源，对生物造成毒性和物理压力。我们已经表明，香根草（Chrysopogon zizanioides）能够耐受和处理来自伊利诺伊州南部废弃的塔布-西姆科（Tab-Simco）采矿场的 AMD 污染水，尽管人们对其耐受机制知之甚少。我们对香根草的茎叶进行了代谢组学分析，这些香根草在接触塔布-西姆科 AMD 的短时间和长时间后进行了处理。与长期 AMD 暴露相比，香根草茎叶的代谢变化显著，包括氨基酸和谷胱甘肽代谢、细胞呼吸和光合作用途径的上调，以及磷酸化代谢物的下调。与此同时，根部分泌物表现出磷脂和磷酸化代谢物、细胞呼吸、乙醛酸代谢和氨基酸代谢的急剧下调。香根草在茎叶中积累了鸟氨酸和草酰乙酸，它们分别可以作为氮储存和各种细胞内功能的功能。根系分泌有机酸和谷胱甘肽进行根际金属螯合，而磷酸化代谢物则被回收用于磷。这些发现揭示了 AMD 诱导的香根草代谢变化，与以前报道的独立非生物胁迫相比，这些变化似乎是独特的。
