接种功能内生细菌对蔬菜亚细胞菲积累的削减作用

蔬菜多环芳烃(PAHs)污染威胁人群健康.通过水培试验,研究了接种具有菲降解功能的植物内生细菌Diaphorobacter sp.Phe15对空心菜及其亚细胞组分中菲积累的影响,揭示了空心菜体内多酚氧化酶(PPO)和过氧化物酶(POD)的响应及其与PAHs积累的相关关系.Phe15可定殖在空心菜体内,不同部位菌株Phe...

Inoculation of endophytic bacteria for the abatement of the phenanthrene accumulation in vegetable subcellular fraction: Efficiency and mechanism

In this study, the changes in phenanthrene contents and enzymatic activities (such as polyphenol oxidase (PPO) and peroxidase (POD)) in water spinach and its subcellular fractions were comprehensively investigated by inoculating a phenanthrene-degrading bacterium Diaphorobacter sp. Phe15, using hydroculture pot experiments. Results showed that strain Phe15 could effectively be colonized into water spinach through root immersion, and the cell counts of Phe15 in each part of water spinach were:root surfaces > inner roots > shoots. Inoculation led to a phenanthrene content reduction of 93.69% and 50.26% in roots and shoots, respectively, resulting in a decreased concentration in the subcellular fractions of water spinach. The phenanthrene content decreased the most in cell soluble fractions. Also, the enzymatic activities of POD and PPO in roots, shoots, and subcellular fractions of water spinach increased with the inoculation of Phe15. Notably, the enzymatic activities of POD and PPO negatively correlated with the contents of phenanthrene in water spinach, indicating that the increased activities of these enzymes would lead to a decrease in phenanthrene content in plants. The findings in this study reveals the underlying mechanisms of endophytic PAH degradation in plants, from the perspective of subcellular fractions and enzyme activity. This study will provide the necessary theoretical basis for using bacterial endophytes in reducing the risks while ensuring agricultural crop safety in PAH-contaminated fields.