Seasonal change in susceptibility of Pinus densiflora to Bursaphelenchus xylophilus infection, determined from the number of nematodes passing through branch sections

Nematology ◽  
2009 ◽  
Vol 11 (3) ◽  
pp. 409-418 ◽  
Author(s):  
Koji Matsunaga ◽  
Katsumi Togashi
Keyword(s):  
Seasonal Change ◽  
Developmental Stages ◽  
Pinus Densiflora ◽  
Pine Wilt Disease ◽  
Bursaphelenchus Xylophilus ◽  
Control Measures ◽  
Effective Control ◽  
Dispersal Ability ◽  
Second Stage ◽  
Individual Branch

AbstractPine wilt disease by Bursaphelenchus xylophilus has been causing devastating damage to Pinus densiflora and P. thunbergii forests in Japan. Reforestation using resistant trees is one of the most effective control measures. In this study we examined the seasonal change in the number of nematodes passing through 5 cm long P. densiflora branch sections during 24 h, to determine the season of greatest susceptibility when resistant candidates can be identified easily. We inoculated 200 nematodes of each of four B. xylophilus and one B. mucronatus isolate on the cut end of individual branch sections. The overall seasonal change in the number of nematodes passing was similar among the five isolates. Peaks occurred in August and between December and February for four isolates. A virulent isolate, T-4, exhibited remarkable fluctuations, with the highest peak in August, suggesting that a test in August with T-4 is most informative. Another study showed that the passage ability, which is a measure of the dispersal ability in branches, was low for eggs and second-stage propagative juveniles and high for other developmental stages. This indicates that the composition of developmental stages in the inoculum is important when comparing the numbers of passing nematodes obtained on different occasions and in different places.

Between-isolate difference in dispersal ability of Bursaphelenchus xylophilus and vulnerability to inhibition by Pinus densiflora

Nematology ◽  
2003 ◽  
Vol 5 (4) ◽  
pp. 559-564 ◽  
Author(s):  
Katsumi Togashi ◽  
Koji Matsunaga
Keyword(s):  
Pinus Densiflora ◽  
Pine Wilt Disease ◽  
Inhibitory Effect ◽  
Bursaphelenchus Xylophilus ◽  
Wilt Disease ◽  
Dispersal Ability ◽  
Pine Wilt ◽  
Pine Species

Abstract Differences among four isolates of Bursaphelenchus xylophilus and one of B. mucronatus in vulnerability to the inhibitory effect of Pinus densiflora on nematode dispersal were investigated by inoculating boiled and living branch sections 5 cm long. The intrinsic dispersal ability and vulnerability to the inhibitory effect of living branches differed among isolates. Additionally, the degree of branch inhibition of nematode dispersal was examined by inoculating the five isolates on 2.5 and 5.0 cm long, P. densiflora living branch sections. An increase in section length induced an 80% decrease in the number of nematodes of all isolates passing through the branch. The extent to which passing nematode number decreased as branch section length increased can be used to express susceptibility of pine species to pine wilt disease. Virulence had no relation to intrinsic and realised dispersal rates in B. xylophilus.

scholarly journals Whole-organism Transcriptomic Insight Into the Effects of Cytco, A Novel Nematotoxic Protein on the Pine Wood Nematode Bursaphelenchus Xylophilus 

2021 ◽  
Author(s):  
Ye Chen ◽  
Xiang Zhou ◽  
Kai Guo ◽  
Sha-Ni Chen ◽  
Xiu Su
Keyword(s):  
Enrichment Analysis ◽  
Transcriptome Profiling ◽  
Bursaphelenchus Xylophilus ◽  
Control Measures ◽  
Effective Control ◽  
Large Set ◽  
Pine Wood Nematode ◽  
Pine Wood ◽  
Protein Toxin ◽  
Insight Into

Abstract Background: The pine wood nematode Bursaphelenchus xylophilus is a worldwide destructive pest on Pinus trees and lacks effective control measures. Screening nematotoxic protein toxins has been conducted to develop new strategies for nematode control. Results: The present study provided initial insights into the responses of B. xylophilus exposed to a nematocidal cytolytic-like protein (CytCo) based on the transcriptome profiling. A large set of differentially expressed genes (1266 DEGs) were found related to nematode development, reproduction, metabolism, motion, and immune system. In response to the toxic protein, B. xylophilus upregulated DEGs encoding cuticle collagens, transporters, and cytochrome P450. In addition, many DEGs related to cell death, lipid metabolism, major sperm proteins, proteinases/peptidases, phosphatases, kinases, virulence factors, and transthyretin-like proteins were downregulated. And Gene Ontology enrichment analysis showed that CytCo treatment significantly affecting DEGs functioning in muscle contraction, lipid localization, MAPK cascade. The pathway richness of Kyoto Encyclopedia of Genes and Genomes showed that the DEGs were concentrated in lysosome and fatty acid degradation. The weight co-expression network analysis indicated that the hub genes affected by CytCo were associated with the nematode cuticular collagen. Conclusions: These results showed that the CytCo protein toxin could interference gene expression to produce multiple nematotoxic effects, providing initial insight into its control potential of pine wood nematode.

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.

Inhibition response of Pinus densiflora clones to Bursaphelenchus xylophilus systemic dispersal and their resistance to pine wilt disease

Nematology ◽  
2011 ◽  
Vol 13 (6) ◽  
pp. 653-659 ◽  
Author(s):  
Katsumi Togashi ◽  
Hiroko Maezono ◽  
Koji Matsunaga ◽  
Satoshi Tamaki
Keyword(s):  
Pinus Densiflora ◽  
Resistance Mechanism ◽  
Pine Wilt Disease ◽  
Bursaphelenchus Xylophilus ◽  
Wilt Disease ◽  
Pine Wilt ◽  
Inhibition Response ◽  
The Mean ◽  
The Relationship ◽  
Clone Group

AbstractTo determine the relationship between resistance to pine wilt disease and the inhibition of nematode systemic dispersal in Pinus densiflora, a suspension of 200 Bursaphelenchus xylophilus was placed on the upper cut end of 5-cm-long, living or boiled branch sections of 17 clones of pine that had different resistance levels. Significantly more nematodes passed through boiled sections than living sections during 24 h. Living branches of the resistant P. densiflora clone group significantly suppressed the dispersal of B. xylophilus compared with those of the susceptible group, suggesting that the inhibition of nematode systemic dispersal was involved in the resistance mechanism of selected disease-resistant pine clones. However, there was no significant correlation between the resistance class and the mean number of nematodes passing through live branch sections within the resistant clone group. The reason for the lack of correlation is discussed in relation with the resistance mechanism.

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 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.

Resistance of an indigenous biological system against expansion of the invasive nematode, Bursaphelenchus xylophilus, in cool areas of Japan

Nematology ◽  
2008 ◽  
Vol 10 (5) ◽  
pp. 679-687 ◽  
Author(s):  
Shota Jikumaru ◽  
Katsumi Togashi
Keyword(s):  
Air Temperature ◽  
Pinus Densiflora ◽  
Pine Wilt Disease ◽  
Bursaphelenchus Xylophilus ◽  
Vector System ◽  
Insect Vector ◽  
Disease Development ◽  
Biotic Factors ◽  
Pine Tree ◽  
Pine Trees

Abstract Bursaphelenchus xylophilus is the pathogen associated with pine wilt disease (PWD), an infectious disease of pine trees transmitted by cerambycid beetles of the genus Monochamus. Bursaphelenchus xylophilus is an invasive species, whilst B. mucronatus is a native congener and non-pathogenic to pine trees in Japan. To provide experiment evidence of the biotic and/or abiotic resistance to PWD expansion in a cool area of Japan, we inoculated B. xylophilus into healthy pine trees in a Japanese red pine (Pinus densiflora) stand with the indigenous pine tree-B. mucronatus-insect vector system before invasion of B. xylophilus in 1993 and 1994. Extremely cool air temperature with high precipitation and extremely high air temperature with low precipitation were observed in the summers of the 2 years of inoculation, respectively. The cool summer induced a low incidence of PWD and delayed disease development, resulting in the replacement of B. xylophilus by B. mucronatus within diseased trees and the emergence of Monochamus saltuarius beetles carrying B. mucronatus from the trees 2 years after the inoculation. The hot summer induced disease development in trees in the year of inoculation, but such diseased trees did not become infection sources because of the lack of M. alternatus, whose oviposition was synchronised with the period of disease development in pine trees. This study indicated that biotic factors were important in the inhibitory mechanism in a pine forest against the spread of PWD in the stand. Relevant biotic factors were the lack of M. alternatus and the presence of M. saltuarius carrying B. mucronatus.

scholarly journals Molecular Cloning and Expression Analysis of the Endogenous Cellulase Gene MaCel1 in Monochamus alternatus

Forests ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1372
Author(s):  
Yachao Li ◽  
Hao Chen ◽  
Xu Chu ◽  
Qiuyu Ma ◽  
Guanghong Liang ◽  
...  
Keyword(s):  
Amino Acids ◽  
Developmental Stages ◽  
Sequence Similarity ◽  
Pupal Stage ◽  
Pine Wilt Disease ◽  
Bursaphelenchus Xylophilus ◽  
Cloning And Expression ◽  
Cellulase Gene ◽  
Monochamus Alternatus ◽  
Real Time Quantitative Pcr

The purpose of this study was to characterize the endogenous cellulase gene MaCel1 of Monochamus alternatus, which is an important vector of Bursaphelenchus xylophilus, a pine wood nematode, which causes pine wilt disease (PWD). In this study, MaCel1 was cloned by rapid amplification of cDNA end (RACE), and its expression analyzed by RT-qPCR (real-time quantitative PCR detecting). A total of 1778 bp of cDNA was obtained. The encoding region of this gene was 1509 bp in length, encoding a protein containing 502 amino acids with a molecular weight of 58.66 kDa, and the isoelectric point of 5.46. Sequence similarity analysis showed that the amino acids sequence of MaCel1 had high similarity with the β-Glucosinolate of Anoplophoraglabripennis and slightly lower similarity with other insect cellulase genes (GH1). The β-D-Glucosidase activity of MaCel1 was 256.02 ± 43.14 U/L with no β-Glucosinolate activity. MaCel1 gene was widely expressed in the intestine of M. alternatus. The expression level of MaCel1 gene in male (3.46) and female (3.51) adults was significantly higher than that in other developmental stages, and the lowest was in pupal stage (0.15). The results will help reveal the digestive mechanism of M. alternatus and lay the foundation for controlling PWD by controlling M. alternatus.

Is Bursaphelenchus mucronatus a weak pathogen to the Japanese red pine?

Nematology ◽  
2006 ◽  
Vol 8 (4) ◽  
pp. 485-489 ◽  
Author(s):  
Kazuyoshi Futai ◽  
Natsumi Kanzaki
Keyword(s):  
Pinus Densiflora ◽  
Pine Wilt Disease ◽  
Bursaphelenchus Xylophilus ◽  
Transmission Efficiency ◽  
Monochamus Alternatus ◽  
Disease Symptoms ◽  
Host Trees ◽  
Bursaphelenchus Mucronatus ◽  
Pine Trees ◽  
Mutualistic Relationship

AbstractThe pine wood nematode, Bursaphelenchus xylophilus, is the causal agent of pine wilt disease. It can invade healthy pine trees through the feeding wound of its vector beetle, Monochamus alternatus, and can enter a dead or dying tree through the vector's oviposition mark. By contrast, B. mucronatus, which is closely related to B. xylophilus but has been considered to have no pathogenicity to pine species, also invades living host trees through the same process as B. xylophilus, although the transmission efficiency is lower than that of B. xylophilus. In order to clarify the reason why Bursaphelenchus mucronatus invades a living host, we inoculated shaded and unshaded host seedlings of Pinus densiflora with B. mucronatus. Bursaphelenchus mucronatus displayed pathogenicity in the host seedlings but only with those that were shaded. In addition, B. mucronatus was recovered from the seedlings that had survived until the end of the experiment. Bursaphelenchus mucronatus seems to survive in the living healthy host tree without causing disease symptoms. These results suggest a mutualistic relationship between B. mucronatus and its vector beetle.

The effect of endobacteria on the development and virulence of the pine wood nematode, Bursaphelenchus xylophilus

Nematology ◽  
2015 ◽  
Vol 17 (5) ◽  
pp. 581-589 ◽  
Author(s):  
Xiao-Jing Tian ◽  
Xiao-Qin Wu ◽  
Yang Xiang ◽  
Xin Fang ◽  
Jian-Ren Ye
Keyword(s):  
Stenotrophomonas Maltophilia ◽  
Pinus Densiflora ◽  
Pine Wilt Disease ◽  
Bursaphelenchus Xylophilus ◽  
Wilt Disease ◽  
Achromobacter Xylosoxidans ◽  
Pine Wood Nematode ◽  
Pine Wood ◽  
Forest Disease ◽  
High Virulence

Pine wilt disease (PWD) caused by the pine wood nematode (PWN), Bursaphelenchus xylophilus, is a destructive forest disease. Recent studies showed that bacteria associated with PWN might play important roles in PWD. In this study, the effects of endobacteria isolated from PWN on the development and virulence of PWN were evaluated. The results revealed that endobacteria isolated from high virulence PWN could partially promote the development of the nematode, while endobacteria from PWN with low virulence could inhibit the development of nematode. Both bacteria-free and non-sterilised nematodes were able to infect microcuttings of Pinus densiflora. The endobacterial isolates, Stenotrophomonas maltophilia NSBx.14 and Achromobacter xylosoxidans ssp. xylosoxidans NSBx.22, enhanced the virulence of low virulence PWN but reduced the virulence of high virulence PWN. The results suggest the pathogenicity of PWN is not affected by loss of bacteria and endobacteria might play a role in the development and virulence of PWN.

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