Abstract：
Polycyclic aromatic compounds (PAHs) are persistent organic pollutants of environmental concern due to their potential impacts on food chain, with plants being particularly vulnerable. While plants can uptake, transport, and transform PAHs, the precise mechanisms underlying their localization and degradation are not fully understood. Here, a cultivation experiment conducted with Panicum miliaceum exposed different concentrations of phenanthrene (PHE). Intermediate PHE degradation compounds were identified via GC-MS analysis, leading to the proposal of a phytodegradation pathway featuring three significant benzene ring cleavage steps. Our results showed that P. miliaceum exhibited the ability to effectively degrade high levels of PHE, resulting in the production of various intermediate products through several chemical changes. Examination of the localization and anatomical characteristics revealed structural alterations linked to PHE stress, with an observed enhancement in PHE accumulation density in both roots and shoots as treatment levels increased. Following a 2-week aging period, a decrease in the amount of PHE accumulation was observed, along with a change in its localization. Bioinformatics analysis of the P. miliaceum 2-oxoglutarate-dependent dioxygenase (2-ODD) DAO-like protein revealed a 299 amino acid structure with two highly conserved domains, namely 2OG-FeII_Oxy and DIOX_N. Molecular docking analysis aligned with experimental results, strongly affirming the potential link and direct action of 2-ODD DAO-like protein with PHE. Our study highlights P. miliaceum capacity for PAHs degradation and elucidates the mechanisms behind enhanced degradation efficiency. By integrating experimental evidence with bioinformatics analysis, we offer valuable insights into the potential applications of plant-based remediation strategies for PAHs-contaminated environments.
摘要：
多环芳香化合物（PAHs）是环境关注的持久性有机污染物，由于它们对食物链的潜在影响，植物特别脆弱。虽然植物可以吸收，运输,转化多环芳烃，其定位和降解的确切机制尚未完全了解。这里,用暴露于不同浓度的菲（PHE）的Panicummiliaceum进行的培养实验。中间PHE降解化合物通过GC-MS分析鉴定，导致提出了具有三个重要苯环裂解步骤的植物降解途径。我们的结果表明，木霉表现出有效降解高水平的PHE的能力，通过几次化学变化导致各种中间产品的生产。对定位和解剖特征的检查显示与PHE应力有关的结构改变，随着处理水平的增加，根和芽中的PHE积累密度均增加。经过2周的衰老，观察到PHE积累量的减少，随着本地化的变化。木霉2-氧戊二酸依赖性双加氧酶（2-ODD）DAO样蛋白的生物信息学分析揭示了具有两个高度保守结构域的299个氨基酸结构，即2OG-FeII_Oxy和DIOX_N。分子对接分析与实验结果一致，强烈肯定2-ODDDAO样蛋白与PHE的潜在联系和直接作用。我们的研究强调了木霉降解PAHs的能力，并阐明了提高降解效率背后的机制。通过将实验证据与生物信息学分析相结合，我们为PAHs污染环境的植物修复策略的潜在应用提供了宝贵的见解。
