六氯苯胁迫对香蒲根系分泌次生代谢物组分的影响

Effect of Hexachlorobenzene Stress on Components of Secondary Metabolites Secreted from Typha angustifolia Roots

【目的】探明湿地水生植物去除水体氯苯类有机污染物的能力,为其在人工湿地生态修复中的应用提供理论支持。【方法】采用水培法结合GC-MS技术研究有机污染物六氯苯(HCB)胁迫下,湿地植物狭叶香蒲(Typha angustifolia)根系分泌次生代谢物、水培液的pH、溶解氧、电导率和氧化还原电位及HCB浓度等指标的变化特征。【结果】培养过程中湿地植物香蒲促进水体HCB浓度降低35%~64%;香蒲根系分泌次生代谢物主要有10种,包括5种烃类、2种酯类、α-毕橙茄醇、1H-3A,6-氢呋喃-2-酮-3-羧酸和油酸酰胺;HCB胁迫导致香蒲根系分泌物收集液导电性增强,氧化还原电位为37.3~88.2 mV;水培30 d后,香蒲根系分泌次生代谢物组分发生改变,1-十二烯和1-十三烯2种烃类,苯甲酸乙酯和邻苯二甲酸甲酯2种酯类的分泌被抑制,正十二烷、1H-3A,6-氢呋喃-2-酮-3-羧酸和油酸酰胺含量分别显著增加27.2%、87.4%和112.6%,而α-毕橙茄醇、正十四烷和α-细辛脑含量分别下降25.7%、68.2%和96.5%;HCB浓度与香蒲根系分泌次生代谢物组分的相关系数为-0.887~0.509,其中,HCB浓度与苯甲酸乙酯呈极显著负相关(r=-0.887,P<0.01)。【结论】HCB胁迫直接影响香蒲根系分泌次生代谢物组分进而影响HCB的生物降解,其中,HCB胁迫下香蒲根系分泌物苯甲酸乙酯可极显著抑制HCB降解。

【Objective】To provide the theoretical support for application of wetland aquatic plants in constructed wetland ecological restoration by probing the removing ability of chlorobenzene organic pollutants of wetland aquatic plants in water.【Method】The change features of secondary metabolites secreted from Typha angustifolia roots,pH,dissolved oxygen,electrical conductivity,redox potential and HCB concentration in hydroponic solution are studied by the hydroponic method combined with GC-MS under HCB stress.【Result】The HCB concentration in water decreases by 35~64%during T.angustifolia cultivation process.Ten main secondary metabolites secreted from T.angustifolia roots including 5 kinds of hydrocarbons,2 kinds of esters,α-Cadinol;1H-3A,6-Methanoazulene-2-ketone-3-Carboxylic Acid and Oleamide are detected during T.angustifolia cultivation process.HCB stress increases the electrical conductivity of T.angustifolia root exudates and the redox potential varies from 37.3 to 88.2 mV.The components of secondary metabolites secreted from T.angustifolia roots after 30 d hydroponic culture.The secretion of 1-Dodecene,1-Tridecene,Ethyl benzoate and Dimethyl phthalate is inhibited,the content of n-Dodecane,1H-3A,6-Methanoazulene-2-ketone-3-Carboxylic Acid andα-Asarone increase by 27.2%,87.4%and 112.6%respectively and the content ofα-Cadinol,n-Tetradecane andα-Asarone decreased by 25.7%,68.2%and 96.5%separately.The correlation coefficient between HCB concentration and different component of secondary metabolites secreted from T.angustifolia roots is-0.887~0.509 and the HCB concentration is very significantly and negatively related to Ethyl benzoate(r=-0.887,P<0.01).【Conclusion】HCB stress influences components of secondary metabolites secreted from T.angustifolia roots directly,which influences HCB biodegradation.The ethyl benzoate secreted from T.angustifolia roots inhibits HCB biodegradation very significantly under HCB stress.