Department of Biochemistry and Biotechnology, Laboratory of Plant and Environmental Biotechnology, University of Thessaly, Larissa, Greece.
Metabolic Insights Ltd, Ness Ziona, Israel.
Pest Manag Sci. 2024 Jun;80(6):2563-2576. doi: 10.1002/ps.7961. Epub 2024 Jan 20.
Natural products present an environmentally attractive alternative to synthetic pesticides which have been implicated in the off-target effect. Currently, the assessment of pesticide toxicity on soil microorganisms relies on the OECD 216 N transformation assay (OECD stands for the Organisation Economic Co-operation and Development, which is a key international standard-setting organisation). We tested the hypotheses that (i) the OECD 216 assay fails to identify unacceptable effects of pesticides on soil microbiota compared to more advanced molecular and standardized tests, and (ii) the natural products tested (dihydrochalcone, isoflavone, aliphatic phenol, and spinosad) are less toxic to soil microbiota compared to a synthetic pesticide compound (3,5-dichloraniline). We determined the following in three different soils: (i) ammonium (NH ) and nitrate (NO ) soil concentrations, as dictated by the OECD 216 test, and (ii) the abundance of phylogenetically (bacteria and fungi) and functionally distinct microbial groups [ammonia-oxidizing archaea (AOA) and bacteria (AOB)] using quantitative polymerase chain reaction (q-PCR).
All pesticides tested exhibited limited persistence, with spinosad demonstrating the highest persistence. None of the pesticides tested showed clear dose-dependent effects on NH and NO levels and the observed effects were <25% of the control, suggesting no unacceptable impacts on soil microorganisms. In contrast, q-PCR measurements revealed (i) distinct negative effects on the abundance of total bacteria and fungi, which were though limited to one of the studied soils, and (ii) a significant reduction in the abundance of both AOA and AOB across soils. This reduction was attributed to both natural products and 3,5-dichloraniline.
Our findings strongly advocate for a revision of the current regulatory framework regarding the toxicity of pesticides to soil microbiota, which should integrate advanced and well-standardized tools. © 2024 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
与被认为具有非靶标效应的合成农药相比，天然产物为环境提供了一种有吸引力的替代选择。目前，评估农药对土壤微生物的毒性依赖于经合组织 216N 转化测定法（经合组织是一个关键的国际标准制定组织）。我们检验了以下两个假设：（i）与更先进的分子和标准化测试相比，经合组织 216 测定法未能识别出农药对土壤微生物群落的不可接受影响；（ii）与合成农药化合物（3,5-二氯苯胺）相比，测试的天然产物（二氢查尔酮、异黄酮、脂肪族酚和多杀菌素）对土壤微生物群落的毒性较低。我们在三种不同的土壤中测定了以下内容：（i）根据经合组织 216 测试，铵（NH ）和硝酸盐（NO ）的土壤浓度，以及（ii）使用定量聚合酶链反应（q-PCR）确定系统发育（细菌和真菌）和功能上不同的微生物群体[氨氧化古菌（AOA）和细菌（AOB）]的丰度。
所有测试的农药都表现出有限的持久性，其中多杀菌素表现出最高的持久性。测试的农药均未表现出明显的剂量依赖性NH 和 NO 水平效应，观察到的效应<对照的 25%，表明对土壤微生物没有不可接受的影响。相比之下，q-PCR 测量结果显示：（i）对总细菌和真菌的丰度有明显的负面影响，但仅限于研究的一种土壤，（ii）在所有土壤中，AOA 和 AOB 的丰度都显著降低。这种减少归因于天然产物和 3,5-二氯苯胺。
我们的研究结果强烈主张修订当前关于农药对土壤微生物群落毒性的监管框架，该框架应纳入先进和标准化的工具。© 2024 作者。《农药科学与管理》由 John Wiley & Sons Ltd 出版，代表化学工业协会。
