Laboratory of Natural Products Pesticides, College of Plant Protection, Southwest University, Chongqing, 400715, China.
Laboratory of Natural Products Pesticides, College of Plant Protection, Southwest University, Chongqing, 400715, China.
Microbiol Res. 2018 Oct;215:15-21. doi: 10.1016/j.micres.2018.05.011. Epub 2018 May 17.
Plant wilt disease caused by the soilborne bacterial pathogen Ralstonia pseudosolanacearum is one of the most devastating plant diseases; however, no effective protection against this disease has been developed. Coumarins are important natural plant-derived compounds with a wide range of bioactivities and extensive applications in medicine and agriculture. In the present study, three hydroxycoumarins (Hycs), umbelliferone (UM), esculetin (ES) and daphnetin (DA) significantly inhibited the growth of R. pseudosolanacearum on solid medium in a concentration-dependent manner, and the minimum inhibitory concentration (MICs) of these compounds was 325 mg L, 125 mg L and 75 mg L, respectively. The percentage of live cells of R. pseudosolanacearum when supplemented with UM, ES, and DA was 63.61%, 17.81% and 7.23%, respectively, which were significantly lower than the DMSO treatment with 92%. Furthermore, irrigating roots with hydroxycoumarins (Hycs) 24 h before inoculation with R. pseudosolanacearum significantly delayed the occurrence of tobacco bacterial wilt, with the control efficiency of the DA treatment (the most efficient of Hycs treatment) 80.03%, 69.83%, 59.19%, 45.49%, 44.12%, 38.27% at 6, 8, 10, 12, 14, and 16 days after inoculation, respectively. Compared with the DMSO treatment, the pathogen populations of tobacco stems supplemented with 100 mg L DA were the lowest, with population significantly reduced by 22.46%, 27.34%, and 18.06% at 4, 7, and 10 days after inoculation, respectively. Based on this study, these Hycs could be applied as potential protective agents in the management of tobacco bacterial wilt.
由土壤细菌病原体雷尔氏菌引起的植物萎蔫病是最具破坏性的植物病害之一；然而，目前尚未开发出有效的防治方法。香豆素是一类重要的天然植物衍生化合物，具有广泛的生物活性，在医学和农业领域有广泛的应用。在本研究中，三种羟基香豆素（Hycs），伞形酮（UM）、七叶内酯（ES）和瑞香素（DA）在浓度依赖性方式下显著抑制了固体培养基中雷尔氏菌的生长，这些化合物的最小抑菌浓度（MICs）分别为 325mg/L、125mg/L 和 75mg/L。当用 UM、ES 和 DA 补充时，雷尔氏菌活细胞的百分比分别为 63.61%、17.81%和 7.23%，明显低于 DMSO 处理的 92%。此外，在接种雷尔氏菌之前 24 小时用羟基香豆素（Hycs）灌根可显著延迟烟草细菌性萎蔫的发生，DA 处理（Hycs 处理中最有效的）的防治效果分别为 80.03%、69.83%、59.19%、45.49%、44.12%、38.27%，在接种后 6、8、10、12、14 和 16 天。与 DMSO 处理相比，补充 100mg/L DA 的烟茎病原体数量最低，在接种后 4、7 和 10 天，分别显著减少了 22.46%、27.34%和 18.06%。基于这项研究，这些 Hycs 可以作为防治烟草细菌性萎蔫病的潜在保护剂。
