Polymyxin B1 and E2 From Paenibacillus polymyxa Y-1 for Controlling Rice Bacterial Disease

Abstract

To discover novel microbial pesticide for controlling rice bacterial disease, polymyxin B1 and E2 were firstly isolated from the supernatant of fermentation broth of Paenibacillus polymyxa Y-1 by bioactivity tracking separation. It is shown that polymyxin B1 and E2 had remarkable in vitro inhibitory activities to Xanthomonas oryzae pv. oryzae (Xoo) and Xanthomonas oryzae pv. oryzicola (Xoc) with the EC50 values of 0.19 μg/ml and 0.21 μg/ml against Xoo, and 0.32 μg/ml and 0.41 μg/ml against Xoc, respectively, which were better than those of Zhongshengmycin (0.31 μg/ml and 0.73 μg/ml) and Bismerthiazol (77.48 μg/ml and 85.30 μg/ml). Polymyxins B1 and E2 had good protection and curative activities against rice bacterial leaf blight (BLB) and rice bacterial leaf streak (BLS) in vivo. The protection and curative activities of polymyxins B1 (45.8 and 35.8%, respectively) and E2 (41.2 and 37.0%, respectively) to BLB were superior to those of Zhongshengmycin (34.8 and 29.8%, respectively) and Bismerthiazol (38.0 and 33.5%, respectively). Meanwhile, the protection and curative activities of polymyxins B1 (44.8 and 39.8%, respectively) and E2 (42.9 and 39.9%, respectively) to BLS were also superior to those of Zhongshengmycin (39.7 and 32.0%, respectively) and Bismerthiazol (41.5 and 34.3%, respectively). Polymyxin B1 exerted the anti-pesticide properties via destroying the cell integrity of Xoo, reducing its infectivity and enhancing rice resistance against pathogens through activating the phenylpropanoid biosynthesis pathway of rice. It is indicated that polymyxin B1 and E2 were potential microbial pesticides for controlling rice bacterial disease.

Abh, AbrB3, and Spo0A play distinct regulatory roles during polymyxin synthesis in Paenibacillus polymyxa SC2

“…Although the polymyxin synthase gene cluster has been identified in several strains, the mechanisms of underlying polymyxin synthesis regulation remain unclear ( 5 , 7 , 8 , 12 ). In the present study, we identified multiple candidate transcription factors that could bind to the promoter region of the pmx cluster based on DNA pull-down assays ( Table S2 ).…”

“…( 7 ). Polymyxins B 1 and E 2 of P. polymyxa Y-1 exert good biocontrol effects against rice bacterial blight and bacterial leaf streak ( 8 ). In addition, polymyxins exhibit therapeutic effects against multidrug-resistant gram-negative bacteria and are considered the last line of defense against multidrug-resistant bacteria ( 9 – 11 ).…”

Isolation and Characterization of Paenibacillus polymyxa B7 and Inhibition of Aspergillus tubingensis A1 by Its Antifungal Substances

“…The biocontrol mechanisms of Bacillus mainly involve competition between Bacillus and pathogens for nutrients and ecological niches [23][24][25], the production of antimicrobial substances [26], interaction between Bacillus and pathogens [27,28], induction of the plant's systemic resistance [29,30], and so on. One of the main antifungal mechanisms in Bacillus is producing compounds with antifungal effects, such as inhibitory proteins [31], inhibitory lipopeptides [19], and other secondary metabolites [32]. Paenibacillus-derived antimicrobials include polymyxins and fusaricides, which are non-ribosomal lipopeptides first isolated from strains of P. polymyxa.…”

Paenibacillus polymyxa YLC1: a promising antagonistic strain for biocontrol of Pseudomonas syringae pv. actinidiae, causing kiwifruit bacterial canker

“…Paenibacillus polymyxa is a plant growth‐promoting rhizobacterium (PGPR) 14 that secretes plant hormones, fixes nitrogen and recruits beneficial rhizosphere microorganisms. Notably, P. polymyxa strains can produce various secondary metabolites and antagonist proteins that inhibit the growth of plant pathogenic fungi 15 and bacteria 16 . P. polymyxa strain ALLI‐03‐01 produces ( l )‐(−)‐3‐phenyllactic acid and fusaricidins to inhibit bacteria infecting rice 17 .…”

“…Notably, P. polymyxa strains can produce various secondary metabolites and antagonist proteins that inhibit the growth of plant pathogenic fungi 15 and bacteria. 16 P. polymyxa strain ALLI-03-01 produces (L)-(−)-3-phenyllactic acid and fusaricidins to inhibit bacteria infecting rice. 17 P. polymyxa strain SCE2 produces phenazine-1-carboxylic acid to effectively inhibit growth of mycotoxinproducing fungi.…”