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=10

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=<p>Microbial bactericides have been a research hotspot in recent years. In order to find new microbial fungicides for preventing and treating rice bacterial diseases, <italic>Paenibacillus polymyxa</italic> Y-1 (<italic>P. polymyxa</italic> Y-1) was isolated from <italic>Dendrobium nobile</italic> in this study, and the optimal medium was selected by a single-factor experiment, and then eight metabolites were isolated from <italic>P. polymyxa</italic> Y-1 fermentation broth by bioactivity tracking separation. The bioassay results showed that 2,4-di-tert-butylphenol, N-acetyl-5-methoxytryptamine, and P-hydroxybenzoic acid have good antibacterial activity against <italic>Xanthomonas oryzae</italic> pv. <italic>Oryzicola</italic> (<italic>Xoo</italic>) and <italic>Xanthomonas oryzae</italic> pv. <italic>oryzae</italic> (<italic>Xoc</italic>), with 50% effective concentration values of 49.45 μg/ml, 64.22 μg/ml, and 16.32 μg/ml to <italic>Xoo</italic>, and 34.33 μg/ml, 71.17 μg/ml, and 15.58 μg/ml to <italic>Xoc</italic>, respectively, compared with zhongshengmycin (0.42 and 0.82 μg/ml, respectively) and bismerthiazol (85.64 and 92.49 μg/ml, respectively). <italic>In vivo</italic> 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) demonstrated excellent protective and curative activity against rice bacterial leaf blight, which were better than 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 under 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.</p>