Dahal Shilu, Alvarez Sophie, Balboa Samantha J, Hicks Leslie M, Rojas Clemencia M
Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, NE 68583-0722, U.S.A.
Center for Biotechnology, University of Nebraska-Lincoln, Lincoln, NE 68588-06653, U.S.A.
Phytopathology. 2024 Dec;114(12):2481-2490. doi: 10.1094/PHYTO-04-24-0140-R. Epub 2024 Dec 11.
Rice production worldwide is threatened by the disease bacterial panicle blight (BPB) caused by . Despite the threat, resources to control this disease, such as completely resistant cultivars or effective chemical methods, are still lacking. However, the need to control this disease has paved the way to explore biologically based approaches harnessing the antimicrobial activities of environmental bacteria. Previously, the bacterium PBL3 was identified as a potential biological control agent against due to its antimicrobial activity against Such antimicrobial activity in vitro and in planta was associated with the PBL3 bacteria-free secreted fraction (secretome), although the specific molecules responsible for this activity have remained elusive. In this work, we advance the characterization of the PBL3 secretome by evaluating the antimicrobial activity in vitro of selected secondary metabolites predicted by the PBL3 genomic sequence against . In addition, using reversed-phase liquid chromatography tandem mass spectrometry of the PBL3 secretome enabled us to successfully detect and quantify pyoluteorin, 2,4-diacetylphloroglucinol, and pyochelin. Among those, pyoluteorin and 2,4-diacetylphloroglucinol reduced the growth of in vitro, along with reducing the symptoms of BPB and bacterial growth in planta, suggesting that these compounds could be effective as biopesticides to mitigate BPB.
全球水稻生产受到由[病原菌名称未给出]引起的细菌性穗枯病（BPB）的威胁。尽管存在这种威胁，但控制该病害的资源，如完全抗性品种或有效的化学方法，仍然匮乏。然而，控制这种病害的需求为探索利用环境细菌抗菌活性的基于生物学的方法铺平了道路。此前，PBL3细菌因其对[病原菌名称未给出]的抗菌活性而被鉴定为一种潜在的生物防治剂。尽管负责这种活性的具体分子仍然难以捉摸，但这种体外和植物体内的抗菌活性与PBL3细菌的无细胞分泌组分（分泌组）有关。在这项工作中，我们通过评估PBL3基因组序列预测的选定次生代谢产物对[病原菌名称未给出]的体外抗菌活性，推进了对PBL3分泌组的表征。此外，利用PBL3分泌组的反相液相色谱串联质谱分析，我们成功地检测并定量了绿脓菌素、2,4 - 二乙酰基间苯三酚和绿脓杆菌素。其中，绿脓菌素和2,4 - 二乙酰基间苯三酚在体外抑制了[病原菌名称未给出]的生长，同时减轻了植物体内BPB的症状和细菌生长，这表明这些化合物作为生物农药减轻BPB可能是有效的。
