Huang Suzhen, Zhu Junying, Zhang Lu, Peng Xue, Zhang Xinyi, Ge Fangjie, Liu Biyun, Wu Zhenbin
State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.
University of Chinese Academy of Sciences, Beijing, China.
Front Microbiol. 2020 Dec 1;11:614570. doi: 10.3389/fmicb.2020.614570. eCollection 2020.
Polyphenols are allelochemicals secreted by aquatic plants that effectively control cyanobacteria blooms. In this study, sensitive response parameters (including CFPs) of were explored under the stress of different polyphenols individually and their combination. The combined effects on were investigated based on the most sensitive parameter and cell densities. For pyrogallic acid (PA) and gallic acid (GA), the sensitivity order of parameters based on the EC values (from 0.73 to 3.40 mg L for PA and from 1.05 to 2.68 mg L for GA) and the results of the hierarchical cluster analysis showed that non-photochemical quenching parameters [NPQ, , and ] > photochemical quenching parameters [YII, , and ] or others [ / , , and UQF] > cell densities. CFPs were not sensitive to ellagic acid (EA) and (+)-catechin (CA). The sensitivity order of parameters for with PA-GA mixture was similar to that under PA and GA stress. The quantitative (Toxicity Index, TI) and qualitative (Isobologram representation) methods were employed to evaluate the combined effects of PA, GA, and CA on based on cell densities and NPQ. TI values based on the EC suggested the additive effects of binary and multiple polyphenols, but synergistic and additive effects according to the EC (varied from 0.16 to 1.94). In terms of NPQ of , the binary polyphenols exhibited synergistic effects when the proportion of high toxic polyphenols PA or GA was lower than 40%, and the three polyphenols showed a synergistic effect only at the ratio of 1:1:1. Similar results were also found by isobologram representation. The results showed that increasing the ratio of high toxic polyphenols would not enhance the allelopathic effects, and the property, proportion and concentrations of polyphenols played an important role in the combined effects. Compared with cell densities, NPQ was a more suitable parameter as evaluating indicators in the combined effects of polyphenols on . These results could provide a method to screen the allelochemicals of polyphenols inhibiting cyanobacteria and improve the inhibitory effects by different polyphenols combined modes.
多酚是水生植物分泌的化感物质，能有效控制蓝藻水华。在本研究中，分别探究了不同多酚及其组合胁迫下（包括叶绿素荧光参数（CFPs）在内的）敏感响应参数。基于最敏感参数和细胞密度研究了其对（相关对象）的联合效应。对于焦性没食子酸（PA）和没食子酸（GA），基于半数效应浓度值（PA为0.73至3.40 mg/L，GA为1.05至2.68 mg/L）的参数敏感性顺序以及层次聚类分析结果表明，非光化学猝灭参数[NPQ、（相关参数）、（相关参数）和（相关参数）]＞光化学猝灭参数[YII、（相关参数）、（相关参数）和（相关参数）]或其他参数[（相关参数）/（相关参数）、（相关参数）、（相关参数）和UQF]＞细胞密度。CFPs对鞣花酸（EA）和（+）-儿茶素（CA）不敏感。PA-GA混合物作用下（相关对象）参数的敏感性顺序与PA和GA胁迫下相似。采用定量（毒性指数，TI）和定性（等效线图表示）方法，基于细胞密度和NPQ评估PA、GA和CA对（相关对象）的联合效应。基于半数效应浓度的TI值表明二元和多种多酚具有相加作用，但根据半数效应浓度（范围为0.16至1.94）则表现为协同和相加作用。就（相关对象）的NPQ而言，当高毒性多酚PA或GA的比例低于40%时，二元多酚表现出协同效应，三种多酚仅在1:1:1的比例下表现出协同效应。等效线图表示也得到了类似结果。结果表明，增加高毒性多酚的比例并不会增强化感作用，多酚的性质、比例和浓度在联合效应中起着重要作用。与细胞密度相比，NPQ作为评估多酚对（相关对象）联合效应的指标更合适。这些结果可为筛选抑制蓝藻的多酚化感物质以及通过不同多酚组合模式提高抑制效果提供一种方法。
