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

Abstract

BackgroundKiwifruit bacterial canker (KBC) caused by Pseudomonas syringae pv. actinidiae (Psa) is the main limiting factor in the kiwifruit industry. This study aimed to identify bacterial strains with antagonistic activity against Psa, analyze antagonistically active substances and provide a new basis for the biological control of KBC.ResultsA total of 142 microorganisms were isolated from the rhizosphere soil of asymptomatic kiwifruit. Among them, an antagonistic bacterial strain was identified as Paenibacillus polymyxa YLC1 by 16S rRNA sequencing. KBC control by strain YLC1 (85.4%) was comparable to copper hydroxide treatment (81.8%) under laboratory conditions and field testing. Active substances of strain YLC1 were identified by genetic sequence analysis using antiSMASH. Six biosynthetic active compound gene clusters were identified as encoding ester peptide synthesis, such as polymyxins. An active fraction was purified and identified as polymyxin B1 using chromatography, hydrogen nuclear magnetic resonance (NMR), and liquid chromatography‐mass spectrometry. In addition, polymyxin B1 also was found significantly to suppress the expression of T3SS‐related genes, but did not affect the growth of Psa at low concentrations.ConclusionIn this study, a biocontrol strain P. polymyxa YLC1 obtained from kiwifruit rhizosphere soil exhibited excellent control effects on KBC in vitro and in field tests. Its active compound was identified as polymyxin B1, which inhibits a variety of pathogenic bacteria. We conclude that P. polymyxa YLC1 is a biocontrol strain with excellent prospects for development and application. © 2023 Society of Chemical Industry.

Streptothricin-F Inhibition of FtsZ Function: A Promising Approach for Controlling Pseudomonas syringae pv. actinidiae

“…Biocontrol bacteria are considered as alternatives to traditional pesticides due to their potential to protect plants from infection by plant pathogens . One way in which biocontrol bacteria achieve this is through the induction of plant resistance by creating a competitive ecological niche .…”

“…The control effect of Psa -induced leaf spot disease was determined using the methods described in the cited literature . In summary, the kiwifruit leaves underwent a disinfection process utilizing a 0.6% NaClO (sodium hypochlorite) solution for a duration of 5 min.…”

“…Finding novel compounds from structurally diverse biocontrol bacteria and identifying new targets for drug action is a meaningful and challenging task . Fortunately, researchers have shifted their focus from only studying the antagonistic effects of biocontrol bacteria against Psa to also investigating the active compounds they produce . The study of the modes of action of these structurally diverse compounds is of great significance for exploring new targets for fungicides …”

Design, Synthesis, and Antibacterial Evaluation of Novel Isoindolin-1-ones Derivatives Containing Piperidine Fragments

“…It can damage the entire orchard and cause a huge economic loss. 9,10 Currently, chemical pesticide control is the main measure to prevent and control crop diseases and pests. Traditional fungicides contain thiamethoxazole, azoxystrobin, carbendazim, carbendazim, zinc thiazole, and toxins.…”

“…It can cause leaf spots, flower rot, leaf detachment, branch ulcers, branch or trunk necrosis, bud browning and detachment, fruit drying and withering, sugar cane withering, and even the grapevine death of kiwifruits. It can damage the entire orchard and cause a huge economic loss. , Currently, chemical pesticide control is the main measure to prevent and control crop diseases and pests. Traditional fungicides contain thiamethoxazole, azoxystrobin, carbendazim, carbendazim, zinc thiazole, and toxins.…”