Phylogenetic characterization of bacterial endophytes from four Pinus species and their nematicidal activity against the pine wood nematode

Abstract

Recently, bacterial endophytes (BEs) have gained importance in the agricultural sector for their use as biocontrol agents to manage plant pathogens. Outbreak of the pine wilt disease (PWD) in Korea has led researchers to test the feasibility of BEs in controlling the pine wood nematode (PWN) Bursaphelenchus xylophilus . In this study, we have reported the diversity and biocontrol activity of BEs against the PWN. By employing a culture-dependent approach, 1,622 BEs were isolated from the needle, stem, and root tissues of P . densiflora , P . rigida , P . thunbergii , and P . koraiensis across 18 sampling sites in Korea. We classified 389 members based on 16S rDNA analysis and taxonomic binning, of which, 215 operational taxonomic units (OTUs) were determined. Using Shannon’s indices, diversity across the Pinus species and tissues was estimated to reveal the composition of BEs and their tissue-specific preferences. When their ethyl acetate crude extracts were analysed for biocontrol activity, 44 candidates with nematicidal activity were obtained. Among these, Stenotrophomonas and Bacillus sp. exhibited significant inhibitory activity against PWN during their developmental stages. Altogether, our study furnishes a basic comprehension of bacterial communities found in the Pinus species and highlights the potential of BEs as biocontrol agents to combat PWD.

Nematicidal Evaluation and Active Compounds Isolation of Aspergillus japonicus ZW1 against Root-Knot Nematodes Meloidogyne incognita

“…Biological options are gaining attention as promising new tools due to their environmentally-friendly and non-toxic characteristics. The potential for using microbes in controlling plant-parasitic nematodes has been documented [38] and effective microbes have been obtained from soil, plants, and the surface of nematodes [39][40][41]. Aspergillus spp.…”

High-Throughput Volatilome Fingerprint Using PTR–ToF–MS Shows Species-Specific Patterns in Mortierella and Closely Related Genera

“…as ethyl acetate (m/z 89.060, C 4 H 8 O 2 H + ) in all our Mortierella s. l. species. Ethyl acetate is generally known as a substance with antibacterial properties against grampositive bacteria [47] and was also reported to have a nematicidal effect [48,49].…”

Wheat Growth Dependent Succession of Culturable Endophytic Bacteria and Their Plant Growth Promoting Traits

“…The maximum number of bacteria was isolated from one month old plant followed by second, third, and seed in descending order. All the genera isolated in this work have been previously reported as endophytic bacteria in various crop systems [1,[41][42][43][44][45][46].…”