scholarly journals Comparative Transcriptomic Response of Two Pinus Species to Infection with the Pine Wood Nematode Bursaphelenchus xylophilus

Forests ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 204
Author(s):  
Gaspar ◽  
Trindade ◽  
Usié ◽  
Meireles ◽  
Fortes ◽  
...  
Keyword(s):  
Differentially Expressed Genes ◽  
Transcriptional Profiling ◽  
Pine Wilt Disease ◽  
Bursaphelenchus Xylophilus ◽  
Differentially Expressed ◽  
Pine Wood Nematode ◽  
Transcriptomic Response ◽  
Pine Wood ◽  
Potential Impact ◽  
Pinus Spp

Pine wilt disease (PWD) caused by pine wood nematode (PWN), Bursaphelenchus xylophilus, is a serious threat to global forest populations of conifers, in particular Pinus spp. Recently, the presence of PWN was reported in dead Yunnan pine (Pinus yunnanensis) trees under natural conditions. To further understand the potential impact caused by PWN in Yunnan pine populations, a transcriptional profiling analysis was performed over different time points (0 hours (h), 6 h, 24 h, 48 h, and 7 days) after PWN inoculation. A total of 9961 differentially expressed genes were identified after inoculation, which suggested a dynamic response against the pathogen, with a more intense pattern at 48 h after inoculation. The results also highlighted a set of biological mechanisms triggered after inoculation that provide valuable information regarding the response of Yunnan pine to PWN infection. When compared with maritime pine (Pinus pinaster), the Yunnan pine response was less complex and involved a smaller number of differentially expressed genes, which may be associated with the increased degree of resistance to PWN displayed by Yunnan pine. These results revealed different strategies to cope with PWN infection by these two pine species, which display contrasting degrees of susceptibility, especially in the timely perception of the infection and response magnitude.

A nested PCR-based method for detecting the pine wood nematode, Bursaphelenchus xylophilus, from pine wood

Nematology ◽  
2005 ◽  
Vol 7 (5) ◽  
pp. 775-782 ◽  
Author(s):  
Kazuyoshi Futai ◽  
Yuko Takeuchi ◽  
Natsumi Kanzaki
Keyword(s):  
Nested Pcr ◽  
Pine Wilt Disease ◽  
Its Region ◽  
Bursaphelenchus Xylophilus ◽  
Pine Wood Nematode ◽  
Pine Wood ◽  
Specific Pcr ◽  
Wide Range ◽  
Ctab Method ◽  
Pinus Spp

AbstractSeveral methods were examined for extracting DNA from the woody tissues of Japanese black pine, including the general CTAB method which proved to be the most successful. To detect the pine wood nematode, the causal agent of pine wilt disease (PWD) in pine wood tissues, PWN-specific PCR was done using a DNA mixture obtained from 80 mg of pine wood tissues and a single pine wood nematode as the DNA template. The results showed that nested PCR could amplify the ITS region specific to the PWN, even though the amount of nematode DNA was extremely small. Also, the PWN could be detected in diseased tissues of several Pinus spp. which had been inoculated with nematodes. The method described here can also be used as a simple and quick detection method for a wide range of wood-inhabiting pathogens.

scholarly journals Cathepsin L-like Cysteine Proteinase Genes Are Associated with the Development and Pathogenicity of Pine Wood Nematode, Bursaphelenchus xylophilus

2019 ◽  
Vol 20 (1) ◽  
pp. 215 ◽  
Author(s):  
Qi Xue ◽  
Xiao-Qin Wu ◽  
Wan-Jun Zhang ◽  
Li-Na Deng ◽  
Miao-Miao Wu
Keyword(s):  
Developmental Stages ◽  
Cysteine Proteinase ◽  
Cathepsin L ◽  
Pine Wilt Disease ◽  
Bursaphelenchus Xylophilus ◽  
Parasitic Nematodes ◽  
Pine Wood Nematode ◽  
Pine Wood ◽  
Real Time Quantitative Pcr ◽  
Rapid Amplification

The pine wood nematode (PWN), Bursaphelenchus xylophilus, is the pathogen of pine wilt disease (PWD), resulting in huge losses in pine forests. However, its pathogenic mechanism remains unclear. The cathepsin L-like cysteine proteinase (CPL) genes are multifunctional genes related to the parasitic abilities of plant-parasitic nematodes, but their functions in PWN remain unclear. We cloned three cpl genes of PWN (Bx-cpls) by rapid amplification of cDNA ends (RACE) and analyzed their characteristics using bioinformatic methods. The tissue specificity of cpl gene of PWN (Bx-cpl) was studied using in situ mRNA hybridization (ISH). The functions of Bx-cpls in development and pathogenicity were investigated using real-time quantitative PCR (qPCR) and RNA interference (RNAi). The results showed that the full-length cDNAs of Bx-cpl-1, Bx-cpl-2, and Bx-cpl-3 were 1163 bp, 1305 bp, and 1302 bp, respectively. Bx-cpls could accumulate specifically in the egg, intestine, and genital system of PWN. During different developmental stages of PWN, the expression of Bx-cpls in the egg stage was highest. After infection, the expression levels of Bx-cpls increased and reached their highest at the initial stage of PWD, then declined gradually. The silencing of Bx-cpl could reduce the feeding, reproduction, and pathogenicity of PWN. These results revealed that Bx-cpls play multiple roles in the development and pathogenic processes of PWN.

Identification of a novel effector BxSapB3 that enhances the virulence of pine wood nematode Bursaphelenchus xylophilus

2019 ◽  
Vol 51 (10) ◽  
pp. 1071-1078
Author(s):  
Xin Huang ◽  
Longjiao Hu ◽  
Xiaoqin Wu
Keyword(s):  
Virulent Strain ◽  
Pine Wilt Disease ◽  
Bursaphelenchus Xylophilus ◽  
Wilt Disease ◽  
Pcr Analysis ◽  
Pine Wood Nematode ◽  
Pine Wood ◽  
Early Stages ◽  
Pine Wilt ◽  
Weakly Virulent

Abstract Pine wilt disease, caused by the pine wood nematode Bursaphelenchus xylophilus, leads to severe damage to pine forests in China. In our previous study, effectors secreted by this pathogen were shown to play roles in the different infection stages of pine wilt disease, and a series of candidate effectors were predicted by transcriptome sequencing. This study identified and characterized a novel effector, BxSapB3, which was among these candidate effectors. Agrobacterium-mediated transient expression was used to identify BxSapB3. BxSapB3 was secreted by B. xylophilus and found to be capable of inducing cell death in Nicotiana benthamiana. Quantitative real-time PCR (qRT-PCR) analysis revealed that BxSapB3 was upregulated in a highly virulent strain of B. xylophilus and expressed at lower levels in a weakly virulent strain at the early stages of infection. When BxSapB3 was silenced in B. xylophilus, the process of infection was delayed. These results indicate that BxSapB3 acts as an effector and contributes to virulence at the early stages of B. xylophilus infection.

scholarly journals Sampling design for efficient detection of pine wood nematode, Bursaphelenchus xylophilus, in diseased trees using a DNA detection kit: variation across branch, trunk and tree

Nematology ◽  
2018 ◽  
Vol 20 (7) ◽  
pp. 641-652 ◽  
Author(s):  
Yuuki Nakabayashi ◽  
Takuya Aikawa ◽  
Michinari Matsushita ◽  
Kazuhiko Hoshizaki
Keyword(s):  
Sampling Design ◽  
Dna Detection ◽  
Pine Wilt Disease ◽  
Bursaphelenchus Xylophilus ◽  
Molecular Techniques ◽  
Effective Control ◽  
Pine Wood Nematode ◽  
Pine Wood ◽  
Efficient Detection ◽  
Minimum Number

Summary Detection of pine wood nematode, Bursaphelenchus xylophilus, is fundamental for effective control of pine wilt disease. Recent molecular techniques, such as DNA detection, have enhanced detectability of the nematodes whereas appropriate field sampling has received less attention. In order to elucidate a sampling design that most efficiently detects B. xylophilus using a commercially-distributed DNA detection kit, we compared detection levels of B. xylophilus using wood chips taken from various positions on dead trees. Results showed that the DNA kit had a higher detection level than the conventional method, and that trunk samples had higher levels than branch samples. Statistical model revealed that among-tree variation influenced the detectability more strongly than within-tree variation. Our results suggest that, in practice, with limited resources for control, it is more efficient to take samples from many trees with a minimum number from each tree, rather than taking many samples from a small number of trees.

scholarly journals Ophiostomatoid fungi associated with pines infected by Bursaphelenchus xylophilus and Monochamus alternatus in China, including three new species

MycoKeys ◽  
2018 ◽  
Vol 39 ◽  
pp. 1-27
Author(s):  
HuiMin Wang ◽  
YingYing Lun ◽  
Quan Lu ◽  
HuiXiang Liu ◽  
Cony Decock ◽  
...  
Keyword(s):  
Dna Sequences ◽  
Pine Wilt Disease ◽  
Molecular Data ◽  
Bursaphelenchus Xylophilus ◽  
Its2 Region ◽  
Ophiostomatoid Fungi ◽  
Pine Wood Nematode ◽  
Pine Wood ◽  
Bark And Ambrosia Beetles ◽  
Japanese Pine Sawyer

The activity of the pine wood nematodeBursaphelenchusxylophilusleads to extremely serious economic, ecological and social losses in East Asia. The nematode causes pine wilt disease, which is currently regarded as the most important forest disease in China. The pathogenic nematode feeds on dendrocola fungi to complete its cycle of infection. As the vector of the nematode, the Japanese pine sawyer (Monochamusalternatus) also carries dendrocola fungi. Pine woods, infected byB.xylophilusand tunnelled byM.alternatus, are also inhabited by ophiostomatoid fungi. These fungi are well known for their association with many bark and ambrosia beetles. They can cause sapstain and other serious tree diseases. The aims of our study were to investigate and identify the ophiostomatoid communities associated with the epidemic pine wood nematode and the pine sawyer inPinusmassonianaandP.thunbergiiforests, which are the main hosts of the pine wood nematode in China. Two hundred and forty strains of ophiostomatoid fungi were isolated from nematode and sawyer–infected trees in the coastal Shandong and Zhejiang Provinces, representing newly and historically infected areas, respectively. Six ophiostomatoid species were identified on the basis of morphological, physiological and molecular data. For the latter, DNA sequences of the internal transcribed spacer (ITS1–5.8S–ITS2) region and partial b-tubulin gene were examined. The ophiostomatoid species included one known species,Ophiostomaips, three novel species, viz.Ophiostomaalbumsp. nov.,Ophiostomamassonianasp. nov.andSporothrixzhejiangensissp. nov.and two species whose identities are still uncertain, Ophiostomacf.deltoideosporum and Graphilbumcf.rectangulosporium, due to the paucity of the materials obtained. The ophiostomatoid community was dominated byO.ips. This study revealed that a relatively high species diversity of ophiostomatoid fungi are associated with pine infected byB.xylophilusandM.alternatusin China.

scholarly journals Assessment of the PCR technique for identification of Bursaphelenchus mucronatus Mamiya & Enda 1979, B. xylophilus Steiner & Buhrer 1934 (Nickle 1970) and B. fraudulentus Rühm 1956 (Nematoda, Aphelenchoididae) in crude extract of nematodes isolated from wood

2021 ◽  
Vol 61 (4) ◽  
pp. 346-351
Keyword(s):  
Pine Wilt Disease ◽  
Bursaphelenchus Xylophilus ◽  
Wilt Disease ◽  
Coniferous Forests ◽  
Pine Wood Nematode ◽  
Direct Examination ◽  
Pine Wood ◽  
Pine Wilt ◽  
Detection And Identification ◽  
Pine Trees

The pine wood nematode, Bursaphelenchus xylophilus Steiner & Buhrer 1934 (Nickle 1970) is the major causative agent of the pine wilt disease which has become devastating to Asian and European coniferous forests. These regions are also naturally occupied by two other native but nonpathogenic species, i.e. B. mucronatus Mamiya & Enda 1979 and B. fraudulentus Rühm 1956 which are closely related to the invasive B. xylophilus. Moreover, all these three species can colonize pine trees, and potentially be extracted from the same wood samples. Due to the cosmopolitan character and wide genetic variation within- and between existing populations the taxonomic distinction of these species based exclusively on their morphology is difficult or, almost impossible. The present quarantine regulations related to B. xylophilus require the most credible and simple methods which could allow for a possibly earliest detection and precise identification of this species in wood shipments and conifer forests stands. The main objectives of the presently reported research were to simplify the presently available procedures for possibly fast and precise detection and identification of B. xylophilus examined in the background of the remaining Bursaphelenchus species of the xylophilus group and other bacterio- and mycetophagous nematodes naturally present in the pine wood samples. The developed method is based on a direct examination of the crude nematode extract from wood samples and subsequent use of PCR technique with earlier designed specific reaction starters amplifying ITS1–28S rDNA regions.

scholarly journals Could Pine Wood Nematode (Bursaphelenchus xylophilus) Cause Pine Wilt Disease or Even Establish inside Healthy Trees in Finland Now—Or Ever?

Forests ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1679
Author(s):  
Juha Tuomola ◽  
Hannah Gruffudd ◽  
Kimmo Ruosteenoja ◽  
Salla Hannunen
Keyword(s):  
Pine Wilt Disease ◽  
Bursaphelenchus Xylophilus ◽  
Wilt Disease ◽  
Pine Wood Nematode ◽  
The European Union ◽  
Climate Data ◽  
Worst Case ◽  
Pine Wood ◽  
Pine Wilt ◽  
Temperature Concept

Pine wilt disease (PWD) caused by the pine wood nematode (PWN, Bursaphelenchus xylophilus) can, in suitable conditions, lead to mass mortality of susceptible trees. In the European Union, PWN is a quarantine pest. To support PWN risk management in Finland, we assessed the suitability of the Finnish present and future climate for both PWD and PWN establishment inside susceptible healthy trees. The former was done using the mean summer temperature concept and the latter by relating annual growing degree days to the likelihoods of PWN extinction and establishment inside healthy trees. The likelihoods were derived from the previously published modelling of PWN population dynamics for 139 locations in Germany. Both assessments were conducted using 10 × 10 km resolution climate data from 2000–2019 and Finland-specific climate change projections for 2030–2080. The results indicate that the present Finnish climate is too cool for both PWD and PWN establishment inside healthy trees. Furthermore, even global warming does not appear to turn the Finnish climate suitable for PWD or PWN establishment inside healthy trees by 2080, except under the worst-case representative concentration pathway scenario (RCP8.5). Consequently, giving top priority to PWN when allocating resources for biosecurity activities in Finland might deserve reconsideration.

scholarly journals Silencing of cyp-33C9 Gene Affects the Reproduction and Pathogenicity of the Pine Wood Nematode, Bursaphelenchus xylophilus

2019 ◽  
Vol 20 (18) ◽  
pp. 4520 ◽  
Author(s):  
Xiuwen Qiu ◽  
Lili Yang ◽  
Jianren Ye ◽  
Wei Wang ◽  
Tiantian Zhao ◽  
...  
Keyword(s):  
Pine Wilt Disease ◽  
Bursaphelenchus Xylophilus ◽  
Economic Losses ◽  
Parasitic Nematodes ◽  
Pine Wood Nematode ◽  
Egg Hatch ◽  
Pine Wood ◽  
Large Numbers ◽  
Cytochrome P450 Genes ◽  
Pine Trees

Cytochrome P450 genes are very important for plant-parasitic nematodes to reproduce and to metabolize xenobiotic compounds generated by their host plants. The pine wood nematode (PWN), Bursaphelenchus xylophilus, causes very high annual economic losses by killing large numbers of pine trees across Asia and into Europe. In this study, we used RNA interference (RNAi) to analyze the function of the cyp-33C9 gene of PWN. Our results showed that expression of the cyp-33C9 gene was suppressed successfully after soaking nematodes for 24 h in cyp-33C9 double-stranded RNA (dsRNA). The silencing of the cyp-33C9 gene significantly decreased the feeding, reproduction, oviposition and egg hatch of B. xylophilus. Meanwhile, the migration speed of B. xylophilus in Pinus thunbergii was reduced in the early stages when the cyp-33C9 gene was silenced in the nematodes. Moreover, knockdown of the cyp-33C9 gene in B. xylophilus caused a decrease in pathogenicity to pine trees. These results suggest that the cyp-33C9 gene plays an important role in the reproduction and pathogenicity of B. xylophilus. This discovery identified several functions of the cyp-33C9 gene in B. xylophilus and provided useful information for understanding the molecular mechanism behind pine wilt disease caused by PWN.

Distribution and pathogenicity of bacteria species carried by Bursaphelenchus xylophilus in China

Nematology ◽  
2003 ◽  
Vol 5 (6) ◽  
pp. 899-906 ◽  
Author(s):  
Bo Guang Zhao ◽  
Hu Li Wang ◽  
Su Fen Han ◽  
Zheng Ming Han
Keyword(s):  
Pine Wilt Disease ◽  
Bursaphelenchus Xylophilus ◽  
Wilt Disease ◽  
Pinus Thunbergii ◽  
Automatic Testing ◽  
Pine Wood Nematode ◽  
Field Inoculation ◽  
Pine Wood ◽  
Pine Wilt

Abstract Bacteria carried by the pine wood nematode (PWN), Bursaphelenchus xylophilus, from both healthy and diseased Pinus thunbergii and P. massoniana were studied in five main pine wilt disease epidemic provinces in P. R. China. No bacteria were found in healthy pines but were found on PWN from all samples collected from diseased trees. Twenty-four bacteria strains were isolated from the nematodes and were identified by a combination of classical and automatic testing bacteriology (ATB) expression methods. Bioassay showed that 17 of the 24 identified strains produced phytotoxins. Eleven of these 17 phytotoxin producers belonged to the genus Pseudomonas. Glasshouse and field inoculation tests using sterile techniques showed that both PWN and the toxin-producing bacteria carried were necessary to induce disease. We hypothesise that pine wilt disease is a complex, induced by both PWN and the bacteria it carries.

scholarly journals Nematicidal Activity of Benzyloxyalkanols against Pine Wood Nematode

Biomolecules ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 384
Author(s):  
Junheon Kim ◽  
Su Jin Lee ◽  
Joon Oh Park ◽  
Kyungjae Andrew Yoon
Keyword(s):  
Forest Ecosystems ◽  
Pine Wilt Disease ◽  
Bursaphelenchus Xylophilus ◽  
Nematicidal Activity ◽  
Environmental Damage ◽  
Pine Wood Nematode ◽  
Glutathione S Transferase ◽  
Pine Wood ◽  
Chemical Treatments ◽  
Continuous Use

Pine wilt disease (PWD) is caused by the pine wood nematode (PWN; Bursaphelenchus xylophilus) and causes severe environmental damage to global pine forest ecosystems. The current strategies used to control PWN are mainly chemical treatments. However, the continuous use of these reagents could result in the development of pesticide-resistant nematodes. Therefore, the present study was undertaken to find potential alternatives to the currently used PWN control agents abamectin and emamectin. Benzyloxyalkanols (BzOROH; R = C2–C9) were synthesized and the nematicidal activity of the synthetic compounds was investigated. Enzymatic inhibitory assays (acetylcholinesterase (AChE) and glutathione S-transferase (GST)) were performed with BzOC8OH and BzOC9OH to understand their mode of action. The benzyloxyalkanols showed higher nematicidal activity than did benzyl alcohol. Among the tested BzOROHs, BzC8OH and BzC9OH showed the strongest nematicidal activity. The LD50 values of BzC8OH and BzC9OH were 246.1 and 158.0 ppm, respectively. No enzyme inhibitory activity was observed for BzC8OH and BzC9OH. The results suggested that benzyloxyalcohols could be an alternative nematicidal agent.

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