Department of Forest Sciences, College of Agriculture and Life Sciences, Seoul National University, Seoul 08826, Republic of Korea; Forest Insect Pests and Diseases Division, National Institute of Forest Science, Seoul 02455, Republic of Korea.
Department of Forest Sciences, College of Agriculture and Life Sciences, Seoul National University, Seoul 08826, Republic of Korea; Bioinformatics Group, R&D Center, Insilicogen, Inc., Yongin-si, Gyeonggi-do 16954, Republic of Korea.
Pestic Biochem Physiol. 2020 May;165:104546. doi: 10.1016/j.pestbp.2020.02.012. Epub 2020 Feb 19.
The fumigant antibacterial activities of 50 plant essential oils belonging to 10 families were investigated against Agrobacterium tumefaciens. Among the test plant essential oils, Cinnamomum verum (cinnamon bark) essential oil showed the most potent fumigant antibacterial activity. When we investigated the antibacterial activities of compounds identified from cinnamon bark essential oil and 9 congeners of trans-cinnamaldehyde, lengths of inhibition zone of trans-cinnamaldehyde, salicylaldehyde and hydrocinnamaldehyde were 1.28, 1.73, and 1.24 cm at 0.625 mg/paper disc concentration, respectively. To determine the mode of action of trans-cinnamaldehyde and salicylaldehyde, intercellular reactive oxygen species (ROS) generation and cell membrane integrity were determined using a confocal laser scanning microscopy. Furthermore, we compared the up- and down-regulated gene expression of A. tumefaciens treated with trans-cinnamaldehyde and salicylaldehyde with that of untreated A. tumefaciens. With cutoffs of |log2FC| > 1 and FDR < 0.05, 29 and 43 down-regulated genes and 27 and 117 up-regulated genes were found in the treatment of trans-cinnamaldehyde and salicylaldehyde, respectively. Based on the ROS generation results, cell membrane integrity assay, and gene expression, we conclude that the antibacterial mode of action of trans-cinnamaldehyde and salicylaldehyde is ROS generation by the Fenton reaction caused by the down-regulation of an ATP synthesis-related gene cluster, corrupted iron ion homeostasis, and a corrupted ROS defense mechanism. The high concentration of ROS damaged the A. tumefaciens cell membrane, which caused cell death.
研究了 10 个科的 50 种植物精油对根癌农杆菌的熏气抗菌活性。在测试的植物精油中，肉桂（肉桂皮）精油表现出最强的熏气抗菌活性。当我们研究肉桂皮精油中的化合物和反式肉桂醛的 9 种同系物的抗菌活性时，反式肉桂醛、水杨醛和氢化肉桂醛在 0.625mg/纸片浓度下的抑菌圈长度分别为 1.28、1.73 和 1.24cm。为了确定反式肉桂醛和水杨醛的作用方式，使用共聚焦激光扫描显微镜测定细胞间活性氧（ROS）的产生和细胞膜完整性。此外，我们比较了用反式肉桂醛和水杨醛处理的根癌农杆菌与未经处理的根癌农杆菌的基因表达上调和下调。用 |log2FC|>1 和 FDR<0.05 的截止值，在反式肉桂醛和水杨醛处理中分别发现了 29 个和 43 个下调基因，以及 27 个和 117 个上调基因。基于 ROS 产生结果、细胞膜完整性测定和基因表达，我们得出结论，反式肉桂醛和水杨醛的抗菌作用模式是由与 ATP 合成相关的基因簇下调引起的 Fenton 反应产生 ROS，破坏铁离子稳态和破坏 ROS 防御机制。高浓度的 ROS 破坏了根癌农杆菌的细胞膜，导致细胞死亡。
