The co-contamination of naphthalene (NAP) and microcystin-LR (MC-LR) commonly occurs in eutrophic waters. However, the joint effects of NAP and MC-LR on plants in aquatic environments remain unknown. Landoltia punctata is characterized by high starch yields and high biomass in polluted waters and has been proven to be a bioenergy crop and phytoremediation plant. In this study, L. punctata was cultured in a nutrient medium with environmentally relevant NAP (0.1, 1, 3, 5, and 10 μg/L) and MC-LR (5, 10, 25, 50, and 100 μg/L) to determine individual and joint toxic effects. The effects of NAP and MC-LR on physiological responses of L. punctata, including growth, starch accumulation, and antioxidant responses, were studied. Bioaccumulation of MC-LR in L. punctata, with or without NAP, was also examined. The results showed that growth and chlorophyll-a contents of L. punctata were reduced at high concentrations of MC-LR (≥ 25 μg/L), NAP (≥ 10 μg/L) and their mixture (≥ 10 + 1 μg/L) after exposure for 7 d. Starch accumulation in L. punctata did not decrease when exposed to NAP and MC-LR, and higher starch content of 29.8 % ± 2.7 % DW could be due to the destruction of starch-degrading enzymes. The antioxidant responses of L. punctata were stronger after exposure to MC-LR + NAP than when exposed to a single pollutant, although not enough to avoid oxidative damage. NAP enhanced the bioaccumulation of MC-LR in L. punctata when NAP concentration was higher than 5 μg/L, suggesting that higher potentials of MC-LR phytoremediation with L. punctata may be observed in NAP and MC-LR co-concomitant waters. This study provides theoretical support for the application of duckweed in eutrophic waters containing organic chemical pollutants.

萘（NAP）和微囊藻毒素-LR（MC-LR）的共同污染通常发生在富营养化的水中。然而，NAP和MC-LR对水生植物的联合作用仍然未知。Landoltia punctata的特征是在污染的水中淀粉含量高，生物量高，已被证明是一种生物能源作物和植物修复植物。在这项研究中，在环境相关的NAP（0.1、1、3、5和10μg/ L）和MC-LR（5、10、25、50和100μg/ L）的营养培养基中培养了点状乳杆菌。），以确定个人和关节的毒性作用。研究了NAP和MC-LR对绣球草生理反应的影响，包括生长，淀粉积累和抗氧化反应。MC-LR在动物体内的生物蓄积还检查了有或没有NAP的点状乳杆菌。结果表明，生长和叶绿素a内容L. punctata的在高浓度MC-LR（≥25微克/升），NAP（≥10微克/升）和它们的混合物（≥10 + 1微克/升的均减少）暴露7天后。当暴露于NAP和MC-LR时，点状湖中的淀粉积累并没有减少，较高的淀粉含量为29.8％±2.7％DW，这可能是由于淀粉降解酶的破坏所致。暴露于MC-LR + NAP后，点状芒的抗氧化反应比暴露于单一污染物时更强，尽管不足以避免氧化损伤。NAP增强MC-LR的生物蓄积在L.点状当NAP浓度高于5μg/ L时，表明在NAP和MC-LR伴生水域中，点状乳杆菌对MC-LR的植物修复潜力更高。该研究为浮萍在含有机化学污染物的富营养化水中的应用提供了理论支持。