Phytotoxic effects of terrestrial dissolved organic matter on a freshwater cyanobacteria and green algae species is affected by plant source and DOM chemical composition.
Phytotoxic effects of terrestrial dissolved organic matter on a freshwater cyanobacteria and green algae species is affected by plant source and DOM chemical composition.
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DOI：
10.1016/j.chemosphere.2017.06.063
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发表时间：
2017-10
期刊：
影响因子：
8.8
通讯作者：
Amanda D Neilen;D. Hawker;K. O’Brien;M. Burford
中科院分区：
文献类型：
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作者：
Amanda D Neilen;D. Hawker;K. O’Brien;M. Burford
在这里，我们将植物源系统发育与其化学特性联系起来，并确定有助于预测DOM对藻类单一培养植物毒性的参数。我们发现，利用紫外可见光谱指数和元素分析对DOM的植物来源进行表征是有用的。具体来说，利用440 nm吸光度值和光谱斜率比系数的组合值来区分裸子植物浸出的DOM和被子植物浸出的DOM。在我们的生物测定中，从4 g叶片L−1中浸出的DOM对9种被测植物中的8种蓝藻的光合产量产生了超过40%的抑制作用。预测产量抑制的重要变量是DOM暴露时间和植物来源，或者使用替代模型，暴露时间和光谱和元素测量。我们的研究提出了光谱指数，可以估计植物来源对水生DOM的贡献，可能提供对生态结果的见解，如植物对藻类的毒性。蓝藻（C. raciborskii）对DOM比绿藻（Monoraphidium spp.）更敏感，随后在五种不同DOM植物源的剂量反应实验中发现。低水平添加被子植物衍生的- dom （0.5 g L−1）对toMonoraphidium sp .具有轻微的植物毒性，可抑制产量30%；raciborskii没有受到影响。较高的DOM添加量（即2 g L−1）对产率c的抑制率为100%。而单孢单胞菌的抑制率在30%以下。藻类对DOM敏感性的差异表明，在水生系统中，来自集水区植被的DOM有可能影响藻类组合。
Here we link plant source phylogeny to its chemical characteristics and determine parameters useful for predicting DOM phytotoxicity towards algal monocultures. We found that DOM characterised using UV–visible spectroscopic indices and elemental analysis is useful for distinguishing DOM plant sources. Specifically, combined values of absorbance at 440 nm and coefficients for the spectral slope ratio, were used to distinguish between gymnosperm-leached DOM and that from angiosperms. In our bioassays, DOM leached from 4 g leaf L−1resulted in over 40% inhibition of photosynthetic yield for the cyanobacterium,Cylindrospermopsis raciborskii, for eight of the nine plants tested. Significant variables for predicting inhibition of yield were DOM exposure time and plant source, or using an alternate model, exposure time and spectroscopic and elemental measures. Our study proposes spectroscopic indices which can estimate a plant source's contribution to aquatic DOM, may provide insights into ecological outcomes, such as phytotoxicity to algae. The cyanobacterium (C. raciborskii)was more sensitive to DOM than a green algae (Monoraphidium spp.), as identified in a subsequent dose-response experiment with five different DOM plant sources. Low level additions of angiosperm derived-DOM (i.e. 0.5 g L−1) were slight phytotoxic toMonoraphidium spp. causing 30% inhibition of yield, whileC. raciborskiiwas not affected. Higher DOM additions (i.e. 2 g L−1) caused 100% inhibition of yield forC. raciborskii, whileMonoraphidium spp. inhibition remained under 30%. The divergence in algal sensitivity to DOM indicates that in aquatic systems, DOM derived from catchment vegetation has the potential to affect algal assemblages.