Bolzonello Angela, Morbiato Laura, Tundo Silvio, Sella Luca, Baccelli Ivan, Echeverrigaray Sergio, Musetti Rita, De Zotti Marta, Favaron Francesco
Department of Land, Environment, Agriculture, and Forestry (TESAF), University of Padova, Legnaro I-35020, Italy.
Department of Chemistry, University of Padova, Padova I-35131, Italy.
Plant Dis. 2023 Sep;107(9):2643-2652. doi: 10.1094/PDIS-09-22-2064-RE. Epub 2023 Sep 11.
, the agent of grapevine downy mildew, causes enormous economic damage, and its control is primarily based on the use of synthetic fungicides. The European Union policies promote reducing reliance on synthetic plant protection products. Biocontrol agents such as spp. constitute a resource for the development of biopesticides. spp. produce secondary metabolites such as peptaibols, but the poor water solubility of peptaibols limits their practical use as agrochemicals. To identify new potential bio-inspired molecules effective against , various water-soluble peptide analogs of the peptaibol trichogin were synthesized. In grapevine leaf disk assays, the peptides analogs at a concentration of 50 μM completely prevented infection after zoosporangia inoculation. Microscopic observations of one of the most effective peptides showed that it causes membrane lysis and cytoplasmic granulation in both zoosporangia and zoospores. Among the effective peptides, 4r was selected for a 2-year field trial experiment. In the vineyard, the peptide administered at 100 μM (equivalent to 129.3 g/ha) significantly reduced the disease incidence and severity on both leaves and bunches, with protection levels similar to those obtained using a cupric fungicide. In the second-year field trial, reduced dosages of the peptide were also tested, and even at the peptide concentration reduced by 50 or 75%, a significant decrease in the disease incidence and severity was obtained at the end of the trial. The peptide did not show any phytotoxic effect. Previously, peptide 4r had been demonstrated to be active against other fungal pathogens, including the grapevine fungus . Thus, this peptide may be a candidate for a broad-spectrum fungicide whose biological properties deserve further investigation.
葡萄霜霉病菌会造成巨大的经济损失，其防治主要依赖合成杀菌剂。欧盟政策推动减少对合成植物保护产品的依赖。诸如某些种的生物防治剂是生物农药开发的资源。某些种会产生诸如肽抗生素等次生代谢产物，但肽抗生素的水溶性差限制了它们作为农用化学品的实际应用。为了鉴定对葡萄霜霉病菌有效的新型潜在仿生分子，合成了肽抗生素trichogin的各种水溶性肽类似物。在葡萄叶盘试验中，浓度为50μM的肽类似物在接种游动孢子囊后完全阻止了葡萄霜霉病菌的感染。对其中一种最有效的肽进行显微镜观察表明，它会导致游动孢子囊和游动孢子的膜裂解和细胞质颗粒化。在有效的肽中，选择了4r进行为期两年的田间试验。在葡萄园里，以100μM（相当于129.3 g/ha）施用该肽可显著降低叶片和果串上的发病率和病情严重程度，其保护水平与使用铜基杀菌剂所获得的保护水平相似。在第二年的田间试验中，也测试了降低剂量的该肽，即使肽浓度降低50%或75%，在试验结束时发病率和病情严重程度仍显著降低。该肽未表现出任何植物毒性作用。此前，已证明肽4r对包括葡萄真菌在内的其他真菌病原体具有活性。因此，这种肽可能是一种广谱杀菌剂的候选物，其生物学特性值得进一步研究。
