Specific and Functional Diversity of Endophytic Bacteria from Pine Wood Nematode Bursaphelenchus Xylophilus with Different Virulence

Wu, Xiaoqin; Yuan, Weimin; Tian, Xiaojing; Fan, Bin; Fang, Xin; Ye, Jian‐Ren; Ding, Xiaolei

doi:10.7150/ijbs.5071

Cited by 56 publications

(57 citation statements)

References 29 publications

(29 reference statements)

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“…We compared our result with the result of a recent study, in which bacteria were obtained from strains of B. xylophilus isolated from naturally wilted pine trees in China48. We found that the composition of bacterial genera and the dominant species are similar, suggesting that the bacterial strains acquired in our study can represent the current microbiomes of PWN.…”

Section: Discussionmentioning

confidence: 52%

Metagenomic analysis of the pinewood nematode microbiome reveals a symbiotic relationship critical for xenobiotics degradation

Cheng

Tian

Wang

et al. 2013

Sci Rep

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Our recent research revealed that pinewood nematode (PWN) possesses few genes encoding enzymes for degrading α-pinene, which is the main compound in pine resin. In this study, we examined the role of PWN microbiome in xenobiotics detoxification by metagenomic and bacteria culture analyses. Functional annotation of metagenomes illustrated that benzoate degradation and its related metabolisms may provide the main metabolic pathways for xenobiotics detoxification in the microbiome, which is obviously different from that in PWN that uses cytochrome P450 metabolism as the main pathway for detoxification. The metabolic pathway of degrading α-pinene is complete in microbiome, but incomplete in PWN genome. Experimental analysis demonstrated that most of tested cultivable bacteria can not only survive the stress of 0.4% α-pinene, but also utilize α-pinene as carbon source for their growth. Our results indicate that PWN and its microbiome have established a potentially mutualistic symbiotic relationship with complementary pathways in detoxification metabolism.

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Section: Discussionmentioning

confidence: 52%

Metagenomic analysis of the pinewood nematode microbiome reveals a symbiotic relationship critical for xenobiotics degradation

Cheng

Tian

Wang

et al. 2013

Sci Rep

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“…xylophilus, commonly known as pine wilt nematode (PWN) and likened to "pine cancer," is a species of nematode that infects pine trees and causes the diseased pines to wilt. Once a pine tree is infected with PWN, there is no effective control measure (22). TVM is more active against B. xylophilus than AVM, IVM, and MBM and might be a potential candidate for PWN control.…”

Section: Resultsmentioning

confidence: 99%

Gene Replacement for the Generation of Designed Novel Avermectin Derivatives with Enhanced Acaricidal and Nematicidal Activities

Huang

Chen²,

Zhang

et al. 2015

Appl Environ Microbiol

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c Avermectin (AVM) and ivermectin (IVM) are potent pesticides and acaricides which have been widely used during the past 30 years. As insect resistance to AVM and IVM is greatly increasing, alternatives are urgently needed. Here, we report two novel AVM derivatives, tenvermectin A (TVM A) and TVM B, which are considered a potential new generation of agricultural and veterinary drugs. The molecules of the TVMs were designed based on structure and pharmacological property comparisons among AVM, IVM, and milbemycin (MBM). To produce TVMs, a genetically engineered strain, MHJ1011, was constructed from Streptomyces avermitilis G8-17, an AVM industrial strain. In MHJ1011, the native aveA1 gene was seamlessly replaced with milA1 from Streptomyces hygroscopicus. The total titer of the two TVMs produced by MHJ1011 reached 3,400 mg/liter. Insecticidal tests proved that TVM had enhanced activities against Tetranychus cinnabarinus and Bursaphelenchus xylophilus, as desired. This study provides a typical example of exploration for novel active compounds through a new method of polyketide synthase (PKS) reassembly for gene replacement. The results of the insecticidal tests may be of use in elucidating the structure-activity relationship of AVMs and MBMs.A vermectins (AVMs) are a series of 16-membered macrocyclic lactone derivatives with potent anthelmintic and insecticidal properties (1, 2). Ivermectin (IVM), a hydrogenated product of AVM B1, has been one of the best-selling antiparasitics since 1981 (3). However, as insect resistance to AVM (4) and IVM (5-7) is on the rise, alternatives or new products with enhanced potency and expanded spectra of activity are urgently needed.Milbemycins (MBMs) are another group of 16-membered macrolides that share similar structures with AVMs. The insecticidal activity of milbemectin (a mixture of MBMs A3 and A4) against some parasites is higher than those of AVM and IVM, while the toxicity is significantly lower (8).The structural differences among AVM, IVM, and MBM are in C-25, C-22-23, and C-13 ( Fig. 1) (9). IVM differs from AVM in C-22-23 (the former has a saturated bond, whereas the latter has a double bond in that position), but its toxicity is lower than that of AVM (10), implying that the single bond in C-22-23 should be the better structure in terms of safety. The major structural difference between IVM and MBM is a bisoleandrosyloxy substituent attached at C-13 of IVM, whereas that position is unsubstituted in MBM. Also, there are different alkyl substituents at C-25: in IVM, the substituent can be isopropyl or secondary butyl, while in MBM, it can be methyl or ethyl. However, MBM is more potent against some parasites and is safer than IVM, suggesting that one or both of the moieties in C-25 and C-13 of MBM is (are) the better structure(s) in these ways than that (those) of IVM. Another conclusion is that the two oleandroses in C-13 are important to the antiparasitic activity of IVM, since their removal will reduce the activity significantly, about 30-fold (10). Based on the curr...

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“…A total of 98 sequences were found: 60 from Portugal in 2010 [8]; 21 from Portugal in 2011 [26]; 2 from China in 2012 [29] and 15 from China in 2013 [12]. The sequences were aligned and the dendrograms were constructed as mentioned above.…”

Section: Methodsmentioning

confidence: 99%

Diversity of Bacteria Carried by Pinewood Nematode in USA and Phylogenetic Comparison with Isolates from Other Countries

et al. 2014

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Pine wilt disease (PWD) is native to North America and has spread to Asia and Europe. Lately, mutualistic relationship has been suggested between the pinewood nematode (PWN), Bursaphelenchus xylophilus the causal nematode agent of PWD, and bacteria. In countries where PWN occurs, nematodes from diseased trees were reported to carry bacteria from several genera. However no data exists for the United States. The objective of this study was to evaluate the diversity of the bacterial community carried by B. xylophilus, isolated from different Pinus spp. with PWD in Nebraska, United States. The bacteria carried by PWN belonged to Gammaproteobacteria (79.9%), Betaproteobacteria (11.7%), Bacilli (5.0%), Alphaproteobacteria (1.7%) and Flavobacteriia (1.7%). Strains from the genera Chryseobacterium and Pigmentiphaga were found associated with the nematode for the first time. These results were compared to results from similar studies conducted from other countries of three continents in order to assess the diversity of bacteria with associated with PWN. The isolates from the United States, Portugal and China belonged to 25 different genera and only strains from the genus Pseudomonas were found in nematodes from all countries. The strains from China were closely related to P. fluorescens and the strains isolated from Portugal and USA were phylogenetically related to P. mohnii and P. lutea. Nematodes from the different countries are associated with bacteria of different species, not supporting a relationship between PWN with a particular bacterial species. Moreover, the diversity of the bacteria carried by the pinewood nematode seems to be related to the geographic area and the Pinus species. The roles these bacteria play within the pine trees or when associated with the nematodes, might be independent of the presence of the nematode in the tree and only related on the bacteria's relationship with the tree.

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Specific and Functional Diversity of Endophytic Bacteria from Pine Wood Nematode Bursaphelenchus Xylophilus with Different Virulence

Cited by 56 publications

References 29 publications

Metagenomic analysis of the pinewood nematode microbiome reveals a symbiotic relationship critical for xenobiotics degradation

Metagenomic analysis of the pinewood nematode microbiome reveals a symbiotic relationship critical for xenobiotics degradation

Gene Replacement for the Generation of Designed Novel Avermectin Derivatives with Enhanced Acaricidal and Nematicidal Activities

Diversity of Bacteria Carried by Pinewood Nematode in USA and Phylogenetic Comparison with Isolates from Other Countries

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