Ballmer Eliane, McNeill Kristopher, Deiner Kristy
Institute of Biogeochemistry and Pollutant Dynamics, ETH Zurich, 8092 Zurich, Switzerland.
Environ Sci Technol Lett. 2024 Nov 26;11(12):1284-1295. doi: 10.1021/acs.estlett.4c00704. eCollection 2024 Dec 10.
Given the severe loss of species richness across diverse ecosystems, there is an urgent need to assess and monitor biodiversity on a global scale. The analysis of environmental DNA (eDNA), referring to any DNA extracted from environmental samples and subsequently sequenced, is a promising method for performing such biodiversity related studies. However, a comprehensive understanding of the factors that drive distinct eDNA degradation rates under different environmental conditions is currently missing, which limits the spatiotemporal interpretations that are possible from the eDNA-based detection of species. Here, we explore what role photochemistry may play in the fate of eDNA in aquatic ecosystems. Since few eDNA photodegradation studies have been performed, we extrapolate measured photochemical degradation dynamics from dissolved organic matter (DOM) and cellular DNA to what is expected for eDNA. Our findings show that photochemistry may dominate eDNA degradation under certain environmental conditions (e.g., DOM-rich waters with no light-limitation) and that photochemical alteration of eDNA may impact microbial respiration rates and the quantitative polymerase chain reaction (qPCR)-based detection of eDNA. We therefore encourage future studies to analyze the impact of photochemistry on eDNA degradation and provide suggested research directions that could help improve the accuracy of spatiotemporal inferences from eDNA analyses.
鉴于不同生态系统中物种丰富度严重丧失，迫切需要在全球范围内评估和监测生物多样性。环境DNA（eDNA）分析是指从环境样本中提取并随后测序的任何DNA，是进行此类生物多样性相关研究的一种很有前景的方法。然而，目前尚缺乏对不同环境条件下驱动eDNA降解速率不同的因素的全面了解，这限制了基于eDNA的物种检测所能进行的时空解释。在这里，我们探讨光化学在水生生态系统中eDNA的命运中可能发挥的作用。由于很少有关于eDNA光降解的研究，我们将从溶解有机物（DOM）和细胞DNA测得的光化学降解动力学外推到eDNA的预期情况。我们的研究结果表明，在某些环境条件下（例如，富含DOM且无光照限制的水域），光化学可能主导eDNA的降解，并且eDNA的光化学改变可能影响微生物呼吸速率以及基于定量聚合酶链反应（qPCR）的eDNA检测。因此，我们鼓励未来的研究分析光化学对eDNA降解的影响，并提供有助于提高基于eDNA分析的时空推断准确性的建议研究方向。
