scholarly journals The Potential of Esteya spp. for the Biocontrol of the Pinewood Nematode, Bursaphelenchus xylophilus

2022 ◽  
Vol 10 (1) ◽  
pp. 168
Author(s):  
David Pires ◽  
Cláudia S. L. Vicente ◽  
Maria L. Inácio ◽  
Manuel Mota
Keyword(s):  
Sustainable Management ◽  
Management Strategies ◽  
Pine Wilt Disease ◽  
Bursaphelenchus Xylophilus ◽  
Nematophagous Fungi ◽  
Climate Change Scenarios ◽  
Pinewood Nematode ◽  
Present Climate ◽  
Future Prospects ◽  
Contingency Plans

The pinewood nematode (PWN), Bursaphelenchus xylophilus, is the causal agent of pine wilt disease (PWD) and a quarantine organism in many countries. Managing PWD involves strict regulations and heavy contingency plans, and present climate change scenarios predict a spread of the disease. The urgent need for sustainable management strategies has led to an increasing interest in promising biocontrol agents capable of suppressing the PWN, like endoparasitic nematophagous fungi of the Esteya genus. Here, we review different aspects of the biology and ecology of these nematophagous fungi and provide future prospects.

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 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 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.

Pine chemical volatiles promote dauer recovery of a pine parasitic nematode, Bursaphelenchus xylophilus

Parasitology ◽  
2019 ◽  
Vol 147 (1) ◽  
pp. 50-57 ◽  
Author(s):  
Wei Zhang ◽  
Yongxia Li ◽  
Long Pan ◽  
Xuan Wang ◽  
Yuqian Feng ◽  
...  
Keyword(s):  
Parasitic Nematode ◽  
Pine Wilt Disease ◽  
Bursaphelenchus Xylophilus ◽  
Wilt Disease ◽  
Pine Forests ◽  
Pinewood Nematode ◽  
Dispersal Stage ◽  
Pine Trees ◽  
The Common ◽  
Gradient Effects

AbstractPinewood nematode, Bursaphelenchus xylophilus, a pine parasitic nematode, poses a serious threat to its host pine forests globally. When dispersal-stage larvae 4 (dauer, DL4) of B. xylophilus enters the new pine, it moults into propagative adult (dauer recovery) and reproduces quickly to kill the host pine. Here, we found pine chemical volatiles, rather than the common dauer recovery factors of nematodes (e.g. suitable temperatures, nutrient availability or density), promote B. xylophilus dauer recovery. The results showed that volatilization of chemicals in host pines could attract DL4 and promote DL4 recovery. To identify which chemicals promote this process, we determined the stimulated activity of the main volatiles of pines including six monoterpenes and two sesquiterpenes. Results showed that all the six monoterpenes promoted dauer recovery, especially β-pinene and β-myrcene, but the two sesquiterpenes have no effect on the transformation. Furthermore, β-pinene performed gradient effects on dauer recovery. We hypothesized that when DL4 infect pine trees, the pine volatiles released from the feeding wounds are used as chemical signals for DL4 transformation to adult to reproduce and rapidly kill the pines. Our study identified the B. xylophilus dauer recovery chemical signal and may contribute to preventing pine wilt disease.

scholarly journals Diel Rhythmicity of Field Responses to Synthetic Pheromone Lures in the Pine Sawyer Monochamus saltuarius

Insects ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 441
Author(s):  
Junheon Kim ◽  
Young Hak Jung ◽  
Sang-Myeong Lee
Keyword(s):  
Forest Ecosystems ◽  
Pinus Densiflora ◽  
Management Strategies ◽  
Pine Wilt Disease ◽  
Bursaphelenchus Xylophilus ◽  
Pinus Koraiensis ◽  
Synthetic Pheromone ◽  
Electronic Timer ◽  
Time Period ◽  
And Control

The pine wood nematode (PWN), Bursaphelenchus xylophilus, causes lethal pine wilt disease (PWD) in Asia and Europe and has become a serious threat to global pine forest ecosystems. In Korea, Monochamus saltuarius transmits PWN not only to Pinus densiflora, but also to Pinus koraiensis, which is widely distributed across eastern Asia. The diel rhythmicity of M. saltuarius in response to its aggregation pheromone was studied with the aim of providing reliable data for the prevention of PWD and control of Monochamus spp. Using a spray dispenser controlled with an electronic timer, M. saltuarius pheromone and attractants (PA) were sprayed to determine the diel rhythm of the response to PA. The spraying period was divided into four time periods: 05:00–11:00 (time period A), 11:00–17:00 (time period B), 17:00–23:00 (time period C), and 23:00–05:00 (time period D). The largest number of M. saltuarius was caught in time period B, followed by A, C, and D. It could be concluded that the flight activity of M. saltuarius in response to PA was diurnal. The results of this study improve the understanding of the behavioral biology of M. saltuarius, allowing for the development of pest management strategies to prevent the spread of PWN and control its vector.

Growth of Esteya vermicola in media amended with nitrogen sources yields conidia with increased predacity and resistance to environmental stress

2011 ◽  
Vol 57 (10) ◽  
pp. 838-843 ◽  
Author(s):  
Zhen Wang ◽  
Chun Yan Wang ◽  
Li Juan Gu ◽  
Yun Bo Wang ◽  
Yong An Zhang ◽  
...  
Keyword(s):  
Environmental Stress ◽  
Ammonium Nitrate ◽  
Significant Influence ◽  
Pine Wilt Disease ◽  
Nitrogen Sources ◽  
Dry Mass ◽  
Bursaphelenchus Xylophilus ◽  
Pinewood Nematode ◽  
Esteya Vermicola ◽  
And Control

Esteya vermicola , an endoparasitic fungus of pinewood nematode, exhibits great potential as a biological agent against nematodes. In this study to enhance the sporulation, predacity, and environmental resistance of E. vermicola, various nitrogen sources, such as glycine, l-leucine, and ammonium nitrate, were tested. The supplement of glycine and l-leucine had a significant influence on the growth rate of the colony, enhancing colony dry mass by 5-fold more than did ammonium nitrate or the control. Of the nitrogen sources tested, ammonium nitrate and l-leucine promoted sporulation, yielding more than 6 × 106 CFU/g, while glycine enhanced the proportion of lunate spores. Meanwhile, the supplement of nitrogen sources had a significant influence on adhesive rate and mortality rate against Bursaphelenchus xylophilus . Moreover, the supplement of glycine enhanced the survival rate against heat stress by more than 3-fold that of l-leucine, ammonium nitrate, and control. The spores produced in media amended with glycine, l-leucine, and ammonium nitrate had slightly but not significantly higher UV resistance and drought resistance than spores produced without nitrogen sources. These results suggested that the addition of glycine resulted in the production of E. vermicola conidia with increased predacity and resistance to environmental stress that may be more suitable for control of pine wilt disease.

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 Prevention of Pine Wilt of Scots Pine (Pinus sylvestris) with Systemic Abamectin Injections

2006 ◽  
Vol 32 (5) ◽  
pp. 195-201
Author(s):  
Randall James ◽  
Ned Tisserat ◽  
Tim Todd
Keyword(s):  
Pinus Sylvestris ◽  
Scots Pine ◽  
Pine Wilt Disease ◽  
Bursaphelenchus Xylophilus ◽  
Wilt Disease ◽  
Pinewood Nematode ◽  
Commercial Formulation ◽  
Breast Height ◽  
Pine Wilt ◽  
Trunk Injection

We examined the efficacy of the insecticide/nematicide abamectin to prevent pine wilt disease caused by the pinewood nematode (Bursaphelenchus xylophilus) in Scots pine (Pinus sylvestris). Pinewood nematode movement was inhibited (>80% death or paralysis) following a 48 hr exposure to abamectin concentrations as low as 0.1 μL a.i. per L (100 ppb). A commercial formulation of abamectin (Avid™) was injected into Scots pine using a pressurized systemic trunk injection tube (STIT) technique. Fifteen to 30 mL (0.45 to 0.90 fl oz) of Avid per STIT could be injected into the trees in less than 1 hr. Trees were successfully injected throughout February, March, and April at temperatures above 4.4°C (40°F). Survival after 1 year of 10 cm diameter (4 in) at breast height (dbh) Scots pines injected with Avid and subsequently inoculated with pinewood nematode was higher (75%) than in pines injected with water (42%). Similarly, survival after 3 years of large Scots pines (30 to 60 cm [12 to 24 in] dbh)] injected with Avid and exposed to a natural epidemic of pine wilt was higher (96%) than in noninjected pines (33%) or those injected with water (71%). These results indicate that preventive injections of Scots pine with Avid are effective in protecting against pine wilt disease.

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