Differential Growth Responses of Marine Phytoplankton to Herbicide Glyphosate.
Differential Growth Responses of Marine Phytoplankton to Herbicide Glyphosate.
复制标题
海洋浮游植物对除草剂草甘膦的差异生长反应
DOI：
10.1371/journal.pone.0151633
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发表时间：
2016
期刊：
影响因子：
3.7
通讯作者：
Lin S
中科院分区：
文献类型：
--
作者：
Wang C;Lin X;Li L;Lin S
草甘膦是一种全球流行的除草剂，其广泛应用可能导致沿海海洋中的磷（P）营养源或浮游植物生长抑制剂的积累。我们研究了草甘膦对14种代表5个主要沿海浮游植物门（附着植物门，硅藻门，甲藻门，针藻门和绿藻门）的生理效应。基于在对比溶解无机磷（DIP）条件下对不同浓度草甘膦的生长反应，我们发现浮游植物物种可分为五组。第Ⅰ组（Emiliania huxleyi、中肋骨条藻和三角褐指藻）可以利用草甘膦作为唯一的磷源来支持无菌培养的生长，但在DIP存在下，它们被36 μM和360 μM草甘膦抑制。第二组（米氏凯伦藻，最小原甲藻，杜氏盐藻，共生藻，赤潮异弯藻（Heterosigma akashiwo）和链状亚历山大藻（Alexandrum catenella）不能利用草甘膦作为唯一的磷源来支持生长，并且在DIP存在下，生长不受36 μM草甘膦的影响，但受360 μM草甘膦的抑制。无论DIP条件如何，甘草酸始终增强第III组（球等鞭金藻）的生长，抑制第IV组（威氏海链藻，海链藻和海洋查顿氏藻）。组V（Amphidinium carterae）对草甘膦没有表现出可测量的反应，无论DIP条件如何。这种分组是不一致的浮游植物物种的系统发育关系，表明功能分化驱动的环境压力。我们的结论是，草甘膦可以被一些物种用作磷源，而对其他物种有毒，但对其他物种没有影响。观察到的差异效应表明，草甘膦的持续使用和这种除草剂在沿海沃茨浓度的增加可能会对沿海海洋浮游植物群落结构产生重大影响。
Glyphosate is a globally popular herbicide to kill weeds and its wide applications may lead to accumulation in coastal oceans as a source of phosphorus (P) nutrient or growth inhibitor of phytoplankton. We studied the physiological effects of glyphosate on fourteen species representing five major coastal phytoplankton phyla (haptophyta, bacillariophyta, dinoflagellata, raphidophyta, and chlorophyta). Based on growth responses to different concentrations of glyphosate under contrasting dissolved inorganic phosphorus (DIP) conditions, we found that phytoplankton species could be classified into five groups. Group I (Emiliania huxleyi, Skeletonema costatum, Phaeodactylum tricornutum) could utilize glyphosate as sole P-source to support growth in axenic culture, but in the presence of DIP, they were inhibited by both 36-μM and 360-μM glyphosate. Group II (Karenia mikimotoi, Prorocentrum minimum, Dunaliella tertiolecta, Symbiodinium sp., Heterosigma akashiwo and Alexandrium catenella) could not utilize glyphosate as sole P-source to support growth, and in the presence of DIP growth was not affected by 36-μM but inhibited by 360-μM glyphosate. Glyphosate consistently enhanced growth of Group III (Isochrysis galbana) and inhibited Group IV (Thalassiosira weissflogii, Thalassiosira pseudonana and Chattonella marina) regardless of DIP condition. Group V (Amphidinium carterae) exhibited no measurable response to glyphosate regardless of DIP condition. This grouping is not congruent with the phylogenetic relationships of the phytoplankton species suggesting functional differentiation driven by environmental pressure. We conclude that glyphosate could be used as P-source by some species while is toxic to some other species and yet has no effects on others. The observed differential effects suggest that the continued use of glyphosate and increasing concentration of this herbicide in the coastal waters will likely exert significant impact on coastal marine phytoplankton community structure.