AUTHOR=Yi Wenshi , Chen Chao , Gan Xiuhai 

TITLE=Active Metabolites From the Endophyte Paenibacillus polymyxa Y-1 of Dendrobium nobile for the Control of Rice Bacterial Diseases

JOURNAL=Frontiers in Chemistry

VOLUME=Volume 10 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2022.879724

DOI=10.3389/fchem.2022.879724

ISSN=2296-2646

ABSTRACT=Microbial fungicides have been a research hotspot in recent years. In order to find new microbial fungicides for preventing and treating rice bacterial diseases, Paenibacillus polymyxa Y-1 (P. polymyxa Y-1) was isolated from Dendrobium nobile in this study, and the optimal medium was selected by single-factor experiment, and then ten metabolites were isolated from P. polymyxa Y-1 by bioactivity tracking separation. When the concentrations were 200 μg/mL and 100 μg/mL, respectively, the bioassay results showed that polymyxin B1 (100%), polymyxin E2 (100%), 2,4-di-tert-butylphenol (82.5 and 72.3 %, 80.1 and 75.2 %, respectively), N-acetyl-5- methoxytryptamine (51.8 and 32.4 %, 50.1 and 40.3 %), P-hydroxybenzoic acid (96.7 and 95.4 %, 98.3 and 96.4 %, respectively) had good antibacterial activity against Xanthomonas oryzae pv. Oryzicola and Xanthomonas oryzae pv. oryzae, which were comparable to those of Zhongshengmycin (100%) and Bismerthiazol (76.4 and 60.2 %, 79.2 and 59.1 %, respectively), the activities were better or equivalent. In vivo experiments found that 2,4-di-tert-butylphenol (35.9% and 35.4%, respectively), N-acetyl-5- methoxytryptamine (42.9% and 36.7%, respectively), and P-hydroxybenzoic acid (40.6% and 36.8%, respectively) had good protective and curative activity against rice bacterial leaf blight, which was equivalent to that of Zhongshengmycin (38.4% and 34.4%, respectively). In addition, after 2,4-di-tert-butylphenol, N-acetyl-5- methoxytryptamine, and P-hydroxybenzoic acid acted on rice, SOD, POD, and CAD defense enzymes increased in the same condition. In conclusion, these results indicated that the activity and mechanism research of new microbial pesticides were helpful for the prevention and control of rice bacterial diseases.