Cortical responses in Japanese black pine to attack by the pine wood nematode

1993 ◽  
Vol 71 (11) ◽  
pp. 1399-1405 ◽  
Author(s):  
Kyoko Ishida ◽  
Taizo Hogetsu ◽  
Kenji Fukuda ◽  
Kazuo Suzuki
Keyword(s):  
Early Stage ◽  
Bursaphelenchus Xylophilus ◽  
Black Pine ◽  
Pine Wood Nematode ◽  
Cortical Tissue ◽  
Pine Wood ◽  
Virulent Isolate ◽  
Bursaphelenchus Mucronatus ◽  
Resin Canals ◽  
Avirulent Isolate

Anatomical and cytochemical changes in the current-year stem cuttings of Japanese black pine (Pinus thunbergii) were investigated in the early stage of infection by a virulent isolate and an avirulent isolate of pine-wood nematode (Bursaphelenchus xylophilus), and an avirulent isolate of another nematode species, Bursaphelenchus mucronatus. Accumulation of lignin- and suberin-like substances around the resin canals in the cortex was shown as a new symptom of the infection by these isolates. Experiments with girdled cuttings demonstrated that more nematodes inhabit and move in the bark than in the xylem and pith at the early stage of infection by the virulent isolate. Death of pine cells occurred first in the epithelial cells of resin canals in the cortex after inoculation with the virulent isolate and then in the cortex and periderm, pith and xylem, and finally the cambium. In branches of 5-year-old seedlings inoculated with avirulent and B. mucronatus isolates, wound periderm was formed surrounding resin canals in the cortex, and cortical cells surrounding the wound periderm were alive. Evidence indicates that nematodes first enter resin canals in the cortex and then invade the surrounding cortical tissue, and that the ability of the virulent nematodes to move into the cortical tissue may be greater than that of the other isolates, accounting for differences in virulence. Key words: Bursaphelenchus xylophilus, Bursaphelenchus mucronatus, virulence, periderm, pine wilt disease, pine-wood nematode.

Influence of fungi on multiplication and distribution of the pine wood nematode, Bursaphelenchus xylophilus, in axenized Pinus thunbergii cuttings

Nematology ◽  
2005 ◽  
Vol 7 (6) ◽  
pp. 809-817 ◽  
Author(s):  
Kazuo Suzuki ◽  
Daisuke Sakaue ◽  
Toshihiro Yamada ◽  
Yu Wang
Keyword(s):  
Population Size ◽  
Early Stage ◽  
Bursaphelenchus Xylophilus ◽  
Pinus Thunbergii ◽  
Disease Development ◽  
Pine Wood Nematode ◽  
Pine Wood ◽  
Inoculation Site ◽  
Fungal Hyphae ◽  
Close Relationship

AbstractInfluence of fungi on multiplication and distribution of the pine wood nematode (PWN), Bursaphelenchus xylophilus, was investigated in Pinus thunbergii cuttings. Axenized nematodes and/or one of two fungi isolated from healthy and PWN-killed P. thunbergii were inoculated together into autoclaved cuttings. A close relationship between the existence and distribution of fungal hyphae, and the multiplication and distribution of PWN was observed. The PWN did not multiply when only axenized nematodes were inoculated in the absence of fungi. When fungi were present, PWN population size increased markedly. The number of nematodes was high at sites where fungal hyphae were distributed. It is suggested that the restriction of a large portion of the nematode population near the inoculation site during the early stage of disease development is closely related to restricted distribution of fungal hyphae.

scholarly journals Early Symptom Development and Histological Changes Associated with Migration of Bursaphelenchus xylophilus in Seedling Tissues of Pinus thunbergii

Plant Disease ◽  
2000 ◽  
Vol 84 (6) ◽  
pp. 675-680 ◽  
Author(s):  
Y. Ichihara ◽  
K. Fukuda ◽  
K. Suzuki
Keyword(s):  
Cell Death ◽  
Bursaphelenchus Xylophilus ◽  
Pinus Thunbergii ◽  
Pinewood Nematode ◽  
Symptom Development ◽  
Cortical Tissue ◽  
Early Symptom ◽  
Disease Symptoms ◽  
Virulent Isolate ◽  
Resin Canals

In order to clarify the mechanism of pine wilt caused by the pinewood nematode (PWN), Bursaphelenchus xylophilus, nematode migration in tissues and disease symptoms in Pinus thunbergii seedlings were investigated. One-year-old seedlings were inoculated with different pathogenic isolates of PWN under two different temperatures. At an early stage of symptom development, a virulent isolate of PWN multiplied in both bark and xylem and was distributed in cortical resin canals, cortical tissue, and xylem resin canals at 30°C. Cell death and disease symptoms developed in both bark and xylem. The virulent isolate of PWN at 25°C and the avirulent isolate of PWN at 30°C were distributed mainly in cortical resin canals, but rarely in xylem resin canals and cortical tissue. Disease symptoms and cell death occurred in cortical resin canals and rarely occurred in other tissues. These results demonstrated that the virulent isolate of PWN at low temperature and avirulent nematodes could not easily migrate to xylem resin canals and cortical tissue. It was shown that cell death and early symptom development coincided with PWN migration and, therefore, PWN invasion induces cell death and early symptom development.

The process of epithelial cell death in Pinus thunbergii caused by the pine wood nematode, Bursaphelenchus xylophilus

Nematology ◽  
2014 ◽  
Vol 16 (6) ◽  
pp. 663-668 ◽  
Author(s):  
Joung A. Son ◽  
Joung A. Son ◽  
Taizo Hogetsu ◽  
Joung A. Son ◽  
Taizo Hogetsu ◽  
...  
Keyword(s):  
Epithelial Cell ◽  
Epithelial Cells ◽  
Bursaphelenchus Xylophilus ◽  
Pinus Thunbergii ◽  
Pine Wood Nematode ◽  
Stem Cuttings ◽  
Pine Wood ◽  
A New Technique ◽  
Resin Canals ◽  
Epithelial Cell Death

This study describes a new technique to investigate how the pine wood nematode (PWN), Bursaphelenchus xylophilus, kills pine epithelial cells. After inoculating PWN into 20-cm-long Pinus thunbergii stem cuttings and incubating for 1, 3 or 7 days, the cuttings were split into 2.5 cm segments. The segments were tangentially cut so that the epithelia of several cortical resin canals were exposed, and these were stained with Evans Blue for the detection of dead epithelial cells. While almost no dead epithelial cells were found in the cortical resin canals of non-PWN-inoculated control cuttings up to day 7 of the experiment, dead epithelial cells were distributed sparsely in the epithelium of cortical resin canals throughout pine cuttings inoculated with PWN 1, 3 and 7 days after inoculation. The sparse and sporadic distribution of dead pine cells in the epithelium suggested that individual PWN attacked one epithelial cell at a time with its stylet and migrated between attacks.

scholarly journals The effect of feeding behavior of Monochamus alternatus (Coleoptera: Cerambycidae) on the departure of pine wood nematode, Bursaphelenchus xylophilus (Nematoda: Aphelenchoididae)

2019 ◽  
Author(s):  
Yang Wang ◽  
Fengmao Chen ◽  
Lichao Wang ◽  
Lifeng Zhou ◽  
Juan Song
Keyword(s):  
Oxidative Phosphorylation ◽  
Feeding Behavior ◽  
Bursaphelenchus Xylophilus ◽  
Pine Wood Nematode ◽  
Monochamus Alternatus ◽  
Pine Wood ◽  
Start Date ◽  
Significant Difference ◽  
Departure Date ◽  
Effect Of Feeding

AbstractIn order to study the causes of pine wood nematode (PWN) departure from Monochamus alternatus, the effects of the feeding behavior of M. alternatus on the start date of the departure of PWN were studied. The start date of the departure of PWN carried by the directly fed M. alternatus was 5—13 d after beetle emergence, mainly concentrated within 6—10 d, with a mean (±SD) of 8.02 ± 1.96 d. The start date of the departure of PWN carried by the M. alternatus fed after starvation was 5—14 d after beetle emergence, mainly concentrated within 6—9 d, with a mean of 7.76 ± 2.28 d. The results show that there was no significant difference in the start departure date of PWN between the two treatments. This shows that the feeding behavior of M. alternatus is not the trigger for PWN departure. At the same time, it was found that the motility of the PWN carried by M. alternatus at 8 d after emergence was significantly greater than that of the PWN carried by the newly emerged M. alternatus. And the PWN carried by M. alternatus at 8 d after emergence was extracted more easily than the PWN carried by newly emerged beetles. These results show that greater motility was associated with easier departure of PWN from M. alternatus. In addition, transcriptome sequencing found that the level of oxidative phosphorylation metabolism of PWN carried by beetles at 8 d after emergence was significantly higher than that in the PWN carried by newly emerged beetle. High oxidative phosphorylation was associated with increased energy production and motility by the PWN and were the internal cause of the start of nematode departure.

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.

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