Werrie Pierre-Yves, Burgeon Clément, Le Goff Guillaume Jean, Hance Thierry, Fauconnier Marie-Laure
Laboratory of Chemistry of Natural Molecules, Gembloux Agro-Bio Tech, University of Liège, Gembloux, Belgium.
Biodiversity Research Center, Earth and Life Institute, Université catholique de Louvain, Louvain-la-Neuve, Belgium.
Front Plant Sci. 2021 Apr 9;12:650132. doi: 10.3389/fpls.2021.650132. eCollection 2021.
The use of conventional pesticides is debated because of their multiple potential adverse effects on non-target organisms, human health, pest resistance development and environmental contaminations. In this setting, this study focused on developing alternatives, such as trunk-injected essential oil (EO)-based biopesticides. We analysed the ecophysiology of apple trees () following the injection of and nanoemulsions in the tree's vascular system. Targeted and untargeted volatile organic compounds (VOCs) analyses were performed on leaf-contained and leaf-emitted VOCs and analysed through dynamic headspace-gas chromatography-mass spectrometry (DHS-GC-MS) and thermal desorption unit (TDU)-GC-MS. Our results showed that carvone, as a major constituent of the EO, was contained in the leaves (mean concentrations ranging from 3.39 to 19.7 ng g ) and emitted at a constant rate of approximately 0.2 ng g h. -cinnamaldehyde, 's major component, accumulated in the leaves (mean concentrations of 83.46 and 350.54 ng g ) without being emitted. Furthermore, our results highlighted the increase in various VOCs following EO injection, both in terms of leaf-contained VOCs, such as methyl salicylate, and in terms of leaf-emitted VOCs, such as caryophyllene. Principal component analysis (PCA) highlighted differences in terms of VOC profiles. In addition, an analysis of similarity (ANOSIM) and permutational multivariate analysis of variance (PERMANOVA) revealed that the VOC profiles were significantly impacted by the treatment. Maximum yields of photosystem II (Fv/Fm) were within the range of 0.80-0.85, indicating that the trees remained healthy throughout the experiment. Our targeted analysis demonstrated the systemic translocation of EOs through the plant's vascular system. The untargeted analysis, on the other hand, highlighted the potential systemic acquired resistance (SAR) induction by these EOs. Lastly, and EOs did not appear phytotoxic to the treated trees, as demonstrated through chlorophyll fluorescence measurements. Hence, this work can be seen as a proof of concept for the use of trunk-injected EOs given the systemic translocation, increased production and release of biogenic VOCs (BVOCs) and absence of phytotoxicity. Further works should focus on the ecological impact of such treatments in orchards, as well as apple quality and production yields.
由于传统农药对非靶标生物、人类健康、害虫抗药性发展及环境污染具有多种潜在不利影响，其使用存在争议。在此背景下，本研究致力于开发替代方案，如基于树干注射香精油（EO）的生物农药。我们分析了在苹果树（）的维管系统中注射 和 纳米乳液后苹果树的生态生理学。对叶片中所含及释放的挥发性有机化合物（VOC）进行了靶向和非靶向分析，并通过动态顶空 - 气相色谱 - 质谱联用仪（DHS - GC - MS）和热脱附仪（TDU） - GC - MS进行分析。我们的结果表明，香芹酮作为 香精油的主要成分，存在于叶片中（平均浓度范围为3.39至19.7 ng g ），并以约0.2 ng g h的恒定速率释放。 的主要成分 - 肉桂醛在叶片中积累（平均浓度为83.46和350.54 ng g ）但未释放。此外，我们的结果突出了注射香精油后各种VOC的增加情况，无论是在叶片所含的VOC方面，如水杨酸甲酯，还是在叶片释放的VOC方面，如石竹烯。主成分分析（PCA）突出了VOC谱的差异。此外，相似性分析（ANOSIM）和置换多元方差分析（PERMANOVA）表明，VOC谱受到处理的显著影响。光系统II的最大产量（Fv/Fm）在0.80 - 0.85范围内，表明树木在整个实验过程中保持健康。我们的靶向分析证明了香精油通过植物维管系统的系统性转运。另一方面，非靶向分析突出了这些香精油潜在的系统性获得性抗性（SAR）诱导作用。最后，通过叶绿素荧光测量表明， 和 香精油对处理过的树木未表现出植物毒性。因此，鉴于系统性转运、生物源挥发性有机化合物（BVOC）产量增加和释放以及无植物毒性，这项工作可被视为使用树干注射香精油的概念验证。进一步的工作应侧重于此类处理在果园中的生态影响，以及苹果的品质和产量。
