Inhibitory effects of phenazine compounds and VOCs produced by Pseudomonas aurantiaca ST-TJ4 against Phytophthora cinnamomi

• Published in: Phytopathology 2022-03
• Main Authors: Zhang, Yu, Kong, Wei-Liang, Wu, Xiao-Qin, Li, Pu-Sheng
• Format: Article
• Language: English
• ISSN: 0031-949X

Phytophthora cinnamomi is an important plant pathogen that is widely distributed worldwide and has caused serious ecological damage and significant economic losses in forests and plantations in many countries. The use of plant growth-promoting rhizobacteria (PGPR) is an effective and environmentally friendly strategy for controlling diseases caused by P. cinnamomi. In this study, we investigated the antagonistic mechanism of P. aurantiaca ST-TJ4 against P. cinnamomi through different antagonism approaches, observations of mycelial morphology, study of mycelial metabolism and identification of antagonistic substances. The results showed that P. aurantiaca ST-TJ4 was able to significantly inhibit mycelial growth, causing mycelial deformation and disrupting the internal cell structure. Additionally, the pathogen cell membrane was damaged by ST-TJ4, and mycelial cell content synthesis was disrupted. Ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) and gas chromatography-mass spectrometry (GC-MS) analysis showed that phenazine compounds and 2-undecanone were the main antibacterial compounds. The ammonia produced by the ST-TJ4 strain also contributed to the inhibition of the growth of P. cinnamomi. In conclusion, our results confirm that P. aurantiaca ST-TJ4 can inhibit P. cinnamomi through multiple mechanisms and can be used as a biological control agent for various plant diseases caused by P. cinnamomi.