scholarly journals Migration and Multiplication of Pathogenic Bursaphelenchus xylophilus Isolates of Diverse Geographic Origins

2020 ◽  
Vol 3 (1) ◽  
pp. 84
Author(s):  
María Menéndez-Gutiérrez ◽  
Lucía Villar ◽  
Raquel Díaz
Keyword(s):  
Geographic Origin ◽  
Pine Wilt Disease ◽  
Bursaphelenchus Xylophilus ◽  
Fungal Culture ◽  
Multiplication Rate ◽  
Differential Host ◽  
Geographic Origins ◽  
Seedling Inoculation ◽  
The Usa ◽  
Supplementary Material

Unfavorable pine wilt disease expansion predictions require a rapid advance in genetic breeding against the causative agent of this disease, Bursaphelenchus xylophilus. The main strategy for breeding more resistant trees to B. xylophilus, is the use of highly virulent isolates in inoculation experiments. Different inoculation assays were conducted on Botrytis cinerea cultures, in addition to P. pinaster and P. radiata branch sections and seedlings. Seven virulent isolates of different geographic origin (The Japanese nematode isolates S10 and Ka4, the Portuguese Pt72CH and Pt72T, the Spanish SpSA1 and SpPO1, and the American USA745.) were used in the experiments. The main aim of this work is to investigate differences among the seven isolates. The experiments determined that the studied isolates are significantly different. On fungal culture, the isolate from the USA showed the highest multiplication rate. Both seedling inoculation and branch sections experiments pointed to the Portuguese isolate Pt52T and the Spanish SpPo1 as the most virulent to P. pinaster. Conversely, higher numbers of the Pt72CH isolate passed through P. pinaster branch sections. The most virulent isolate for P. radiata was the Japanese S10, though it only showed significant differences in mortality when compared to the Spanish SpSA1. These results suggest that B. xylophilus have differential host specificities. The supplementary material depicts the methodology used in the inoculation assays, as well as shows figures of the most relevant results.

scholarly journals Virulence of Bursaphelenchus xylophilus Isolated from Naturally Infested Pine Forests to Five Resistant Families of Pinus thunbergii

Plant Disease ◽  
2012 ◽  
Vol 96 (2) ◽  
pp. 249-252 ◽  
Author(s):  
Mitsuteru Akiba ◽  
Makoto Ishihara ◽  
Norio Sahashi ◽  
Katsunori Nakamura ◽  
Mineko Ohira ◽  
...  
Keyword(s):  
Disease Incidence ◽  
Pine Wilt Disease ◽  
Bursaphelenchus Xylophilus ◽  
Pinus Thunbergii ◽  
Breeding Program ◽  
Pinewood Nematode ◽  
Differential Host ◽  
Pine Trees ◽  
Efficient Breeding ◽  
Highly Virulent

Pine wilt disease is one of the most serious epidemic tree diseases in Japan, and resistant pine trees have been developed through a breeding program. To evaluate resistance of resistant families of Japanese black pine, Pinus thunbergii, to the pinewood nematode, Bursaphelenchus xylophilus, isolated from the field, and to determine whether differentiation of pathogenicity to resistant pine families appears in the nematode isolates, seedlings of five resistant pine families were inoculated with 25 nematode isolates. Disease incidence 18 weeks after inoculation was significantly different among nematode isolates and among pine families but there was no interaction effect between nematode isolate and pine family. This indicates that nematode isolates did not have differential host specificity to resistant families of P. thunbergii. Isolate Shimabara, a test isolate of the breeding program, showed the same degree of virulence as the highly virulent isolates frequently used in experiments. However, more virulent isolates than Shimabara were found among the isolates collected from natural pine forest. This indicated that B. xylophilus populations with higher virulence than Shimabara exist in the natural population. These findings are important in development of more efficient breeding procedures for resistant pine trees.

scholarly journals Effects of cavitation on the development of pine wilt disease caused by Bursaphelenchus xylophilus.

1988 ◽  
Vol 54 (5) ◽  
pp. 606-615 ◽  
Author(s):  
Keiko KURODA ◽  
Toshihiro YAMADA ◽  
Kazuhiko MINEO ◽  
Hirotada TAMURA
Keyword(s):  
Pine Wilt Disease ◽  
Bursaphelenchus Xylophilus ◽  
Wilt Disease ◽  
Pine Wilt

Enhanced accumulation of pinosylvin stilbenes and related gene expression in Pinus strobus after infection of pine wood nematode

2021 ◽  
Author(s):  
Hwan-Su Hwang ◽  
Jung Yeon Han ◽  
Yong Eui Choi
Keyword(s):  
Transcription Factors ◽  
Defense Mechanisms ◽  
De Novo ◽  
Pinus Strobus ◽  
Pine Wilt Disease ◽  
Monomethyl Ether ◽  
Bursaphelenchus Xylophilus ◽  
Nematicidal Activity ◽  
Dependent Manner ◽  
Pine Wood

Abstract Pine wood nematodes (PWNs: Bursaphelenchus xylophilus) infect pine trees and cause serious pine wilt disease. Eastern white pine (Pinus strobus) has resistance to PWN. However, the detailed defense mechanisms of P. strobus against PWN are not well known. When P. strobus plants were infected with PWNs, the accumulation of stilbenoids, dihydropinosylvin monomethyl ether (DPME) and pinosylvin monomethyl ether (PME), were increased remarkably. DPME and PME had the high nematicidal activity. Interestingly, the nematicidal activity of the two compounds was resulted in a developmental stage-dependent manner. PME was more toxic to adult PWNs than juveniles, whereas DPME was found more toxic to juvenile PWNs than the adults. The genes involved in PME and DPME biosynthesis such as phenylalanine ammonia-lyase (PAL), 4-coumarate-CoA ligase (4CL), pinosylvin synthase (STS), and pinosylvin O-methyltransferase (PMT) were isolated using de novo sequencing of the transcriptome in P. strobus. In addition, transcription factors (bHLH, MYB and WRKY) related to stilbene biosynthesis were isolated. qPCR analyses of the selected genes (PAL, 4CL, STS, and PMT) including transcription factors (bHLH, MYB and WRKY) revealed that the expression level of the selected genes highly enhanced after PWN infection. Our results suggest that pinosylvin-type stilbenoid biosynthesis is highly responsive to PWN infection and plays an important role in PWN resistance of P. strobus trees.

scholarly journals Chitosan increases Pinus pinaster tolerance to the pinewood nematode (Bursaphelenchus xylophilus) by promoting plant antioxidative metabolism

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Marta Nunes da Silva ◽  
Carla S. Santos ◽  
Ana Cruz ◽  
Adrián López-Villamor ◽  
Marta W. Vasconcelos
Keyword(s):  
Phenolic Compounds ◽  
Pinus Pinaster ◽  
Plant Defence ◽  
Pine Wilt Disease ◽  
Bursaphelenchus Xylophilus ◽  
Nematode Population ◽  
Post Inoculation ◽  
Pinewood Nematode ◽  
Plant Tolerance ◽  
The Moment

AbstractThe pine wilt disease (PWD), for which no effective treatment is available at the moment, is a constant threat to Pinus spp. plantations worldwide, being responsible for significant economic and environmental losses every year. It has been demonstrated that elicitation with chitosan increases plant tolerance to the pinewood nematode (PWN) Bursaphelenchus xylophilus, the causal agent of the PWD, but the biochemical and genetic aspects underlying this response have not been explored. To understand the influence of chitosan in Pinus pinaster tolerance against PWN, a low-molecular-weight (327 kDa) chitosan was applied to mock- and PWN-inoculated plants. Nematode population, malondialdehyde (MDA), catalase, carotenoids, anthocyanins, phenolic compounds, lignin and gene expression related to oxidative stress (thioredoxin 1, TRX) and plant defence (defensin, DEF, and a-farnesene synthase, AFS), were analysed at 1, 7, 14, 21 and 28 days post-inoculation (dpi). At 28 dpi, PWN-infected plants elicited with chitosan showed a sixfold lower nematode population when compared to non-elicited plants. Higher levels of MDA, catalase, carotenoids, anthocyanins, phenolic compounds, and lignin were detected in chitosan-elicited plants following infection. The expression levels of DEF gene were higher in elicited plants, while TRX and AFS expression was lower, possibly due to the disease containment-effect of chitosan. Combined, we conclude that chitosan induces pine defences against PWD via modulation of metabolic and transcriptomic mechanisms related with plant antioxidant system.

scholarly journals In Silico Screening of Agonist and Antagonist Natural Compounds from Reported Essential Oils against Bursaphelenchus xylophilus

2020 ◽  
Vol 3 (1) ◽  
pp. 31
Author(s):  
Jorge M. S. Faria ◽  
Ana Margarida Rodrigues ◽  
Pedro Barbosa ◽  
Manuel Mota
Keyword(s):  
Essential Oils ◽  
Pine Wilt Disease ◽  
Natural Compounds ◽  
Bursaphelenchus Xylophilus ◽  
Pinewood Nematode ◽  
Highly Active ◽  
Bibliographic Data ◽  
Agonist And Antagonist ◽  
Containment Strategy ◽  
Detailed Chemical

Chemical control has been the most effective and reliable containment strategy in integrated pest management of pine wilt disease (PWD), caused by the pinewood nematode (PWN), Bursaphelenchus xylophilus. Yet, large spectrum nematicides can be dangerous to human health and the environment. Essential oils (EOs) are safer sustainable alternatives, being composed of highly active natural compounds. A survey of bibliographic data on the detailed chemical composition and activity of the EOs used against the PWN allowed pinpointing monoterpenes as the main source of structures with agonist or antagonist properties. Transversal EO data treatment can identify potential highly active anti-PWN compounds.

scholarly journals Constitutive Chemical Compounds in Different Tissues of Seven Pine Species and Their Relationship with Susceptibility to Pine Wood Nematode (Bursaphelenchus xylophilus)

2020 ◽  
Vol 3 (1) ◽  
pp. 68
Author(s):  
Margarita Alonso Santos ◽  
María Menéndez-Gutiérrez ◽  
Raquel Díaz Vazquez
Keyword(s):  
Condensed Tannin ◽  
Pine Wilt Disease ◽  
Interspecific Variation ◽  
Bursaphelenchus Xylophilus ◽  
Soluble Carbohydrates ◽  
Total Polyphenols ◽  
North West ◽  
Calcium Iron ◽  
Susceptible Group ◽  
Pine Species

Pine wilt disease was detected in Galicia (North West of Spain) in 2010. Two-year-old seedlings of seven pine species were inoculated with B. xylophilus, and three different groups were stablished: non-susceptible (P. canariensis, P. taeda, P. halepensis, and P. pinea); susceptible (P. pinaster, P. radiata), and highly-susceptible (P. sylvestris). We aimed to determine the interspecific variation of constitutive compounds levels, groups and species, and their relationships with nematode multiplication and mortality. Needles of the non-susceptible group had significantly less water and more nitrogen, potassium, iron, and starch than the others groups; the cortex and phloem of the non-susceptible group had more nitrogen, phosphorus, manganese, and starch, and less potassium, calcium, iron, total polyphenols, condensed tannins and liposoluble substances than the highly susceptible group. The xylem of the non-susceptible group had more N, P, Mg, Mn, total polyphenols, and starch than the other groups. Higher levels of constitutive N and/or starch in any tissue was related with less mortality and nematode multiplication; higher P in the three tissues was also correlated with less nematode multiplication. Moreover, liposoluble substances, soluble carbohydrates and condensed tannin concentration in the needles were negatively correlated with nematode multiplication. On the contrary, in the needles, water content and K were positively correlated with mortality and nematode invasion.

scholarly journals Mitogenome Analysis of Four Lamiinae Species (Coleoptera: Cerambycidae) and Gene Expression Responses by Monochamus alternatus When Infected with the Parasitic Nematode, Bursaphelenchus mucronatus

Insects ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 453
Author(s):  
Zi-Yi Zhang ◽  
Jia-Yin Guan ◽  
Yu-Rou Cao ◽  
Xin-Yi Dai ◽  
Kenneth B. Storey ◽  
...  
Keyword(s):  
Gene Expression ◽  
Phylogenetic Trees ◽  
Mitochondrial Gene ◽  
Mitochondrial Protein ◽  
Pine Wilt Disease ◽  
Bursaphelenchus Xylophilus ◽  
Monochamus Alternatus ◽  
Genome Database ◽  
Protein Coding ◽  
Nd5 Gene

We determined the mitochondrial gene sequence of Monochamus alternatus and three other mitogenomes of Lamiinae (Insect: Coleoptera: Cerambycidae) belonging to three genera (Aulaconotus, Apriona and Paraglenea) to enrich the mitochondrial genome database of Lamiinae and further explore the phylogenetic relationships within the subfamily. Phylogenetic trees of the Lamiinae were built using the Bayesian inference (BI) and maximum likelihood (ML) methods and the monophyly of Monochamus, Anoplophora, and Batocera genera was supported. Anoplophora chinensis, An. glabripennis and Aristobia reticulator were closely related, suggesting they may also be potential vectors for the transmission of the pine wood pathogenic nematode (Bursaphelenchus xylophilus) in addition to M. alternatus, a well-known vector of pine wilt disease. There is a special symbiotic relationship between M. alternatus and Bursaphelenchus xylophilus. As the native sympatric sibling species of B. xylophilus, B. mucronatus also has a specific relationship that is often overlooked. The analysis of mitochondrial gene expression aimed to explore the effect of B. mucronatus on the energy metabolism of the respiratory chain of M. alternatus adults. Using RT-qPCR, we determined and analyzed the expression of eight mitochondrial protein-coding genes (COI, COII, COIII, ND1, ND4, ND5, ATP6, and Cty b) between M. alternatus infected by B. mucronatus and M. alternatus without the nematode. Expression of all the eight mitochondrial genes were up-regulated, particularly the ND4 and ND5 gene, which were up-regulated by 4–5-fold (p < 0.01). Since longicorn beetles have immune responses to nematodes, we believe that their relationship should not be viewed as symbiotic, but classed as parasitic.

scholarly journals Study of symptoms and gene expression in four Pinus species after pinewood nematode infection

2011 ◽  
Vol 9 (2) ◽  
pp. 272-275 ◽  
Author(s):  
Albina R. Franco ◽  
Carla Santos ◽  
Mariana Roriz ◽  
Rui Rodrigues ◽  
Marta R. M. Lima ◽  
...  
Keyword(s):  
Virulent Strain ◽  
Pine Wilt Disease ◽  
Bursaphelenchus Xylophilus ◽  
Wilt Disease ◽  
Pinewood Nematode ◽  
Pine Trees ◽  
Severe Infections ◽  
Genomic Results ◽  
Avirulent Isolate

Pine wilt disease, caused by the pinewood nematode Bursaphelenchus xylophilus (Steiner and Buhrer) Nickle, is originating severe infections in pine trees. The disease is detected when external symptoms appear (e.g. needle chlorosis), but trees could remain asymptomatic for long periods and serve as a long-term host. The primary goal of this study was to assess the effect of inoculation with an avirulent isolate of B. xylophilus (C14-5) on different Pinus spp. seedlings (P. sylvestris, P. nigra, P. pinea and P. pinaster). At the same time, seedlings were also inoculated with a virulent strain, HF, in order to compare the phenotypic and genomic results of the two types of inoculations. The effect of inoculation was determined in terms of expression of various Pinus genes potentially involved in the response to the disease.The results suggest that P. pinea and P. nigra are more resistant to infection by the nematode than P. sylvestris and P. pinaster. The phenotypic and genetic differences were more marked among P. pinea and P. pinaster.

scholarly journals Pseudomonas associated with Bursaphelenchus xylophilus, its insect vector and the host tree: A role in pine wilt disease?

2019 ◽  
Vol 49 (6) ◽  
pp. e12564
Author(s):  
Marta Salgueiro Alves ◽  
Anabela Pereira ◽  
Cláudia Vicente ◽  
Manuel Mota ◽  
Isabel Henriques
Keyword(s):  
Pine Wilt Disease ◽  
Bursaphelenchus Xylophilus ◽  
Wilt Disease ◽  
Host Tree ◽  
Insect Vector ◽  
Pine Wilt

scholarly journals α-l-Fucosidases from Bursaphelenchus xylophilus Secretome—Molecular Characterization and Their Possible Role in Breaking Down Plant Cell Walls

Forests ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 265
Author(s):  
Joana M.S. Cardoso ◽  
Luís Fonseca ◽  
Isabel Abrantes
Keyword(s):  
Cell Wall ◽  
Molecular Characterization ◽  
Three Dimensional ◽  
Pine Wilt Disease ◽  
Bursaphelenchus Xylophilus ◽  
Pinewood Nematode ◽  
Cell Wall Degrading Enzymes ◽  
Degrading Enzymes ◽  
Host Trees ◽  
Resin Canals

The pinewood nematode (PWN) Bursaphelenchus xylophilus, the causal agent of the pine wilt disease (PWD), enters above-ground parts of the tree, migrates through the resin canals and feeds on plant cells causing extensive damage. In order to penetrate the cell wall and establish a parasitic relationship with host trees, the PWN needs to secretea mixture of active cell wall degrading enzymes. In maritime pine, Pinus pinaster, which is high susceptible to PWN, xyloglucan is the major hemicellulosic polysaccharide in primary cells. The xyloglucan backbone is susceptible to hydrolysis by numerous endoglucanases, some of them specific to xyloglucan. However, to completely degrade xyloglucan, all substitutions on the glucan backbones must be released, and l-fucose residues in xyloglucan branches are released by α-l-fucosidases. In the present study, the molecular characterization of two α-l-fucosidases found in PWN secretome was performed. Moreover, a novel α-l-fucosidase was identified and its cDNA and gene sequence were determined. The three-dimensional structures of these α-l-fucosidases were predicted and the transcript levels were analyzed, thus providing new insights into fundamental PWN biology and the possible role of these proteins as cell wall degrading enzymes.

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