scholarly journals Histological Changes in Stems of Pinus sylvestris Seedlings Infected with a Virulent Isolate of the Pinewood Nematode Bursaphelenchus xylophilus

2015 ◽  
Vol 21 (S5) ◽  
pp. 97-98
Author(s):  
Inês Vieira da Silva ◽  
Pedro Barbosa ◽  
Manuel Mota ◽  
Lia Ascensão
Keyword(s):  
Pinus Sylvestris ◽  
Bursaphelenchus Xylophilus ◽  
Pinewood Nematode ◽  
Histological Changes ◽  
Virulent Isolate

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.

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.

scholarly journals Pathogenicity of selected isolates of the quarantine pinewood nematode Bursaphelenchus xylophilus to Scots pine (Pinus sylvestris L.)

2015 ◽  
Vol 55 (4) ◽  
pp. 378-382 ◽  
Author(s):  
Anna Filipiak
Keyword(s):  
Pinus Sylvestris ◽  
Control Plant ◽  
Pine Wilt Disease ◽  
Bursaphelenchus Xylophilus ◽  
Pinewood Nematode ◽  
Plant Mortality ◽  
Disease Symptoms ◽  
Pine Seedlings ◽  
Nematode Virulence ◽  
Different Parts

Abstract The pinewood nematode (PWN), Bursaphelenchus xylophilus, is the causal agent of pine wilt disease (PWD). This nematode is considered to be an indigenous to North America and was introduced to Japan in the late 19th century. Subsequently, it has spread throughout Japan and in many other countries, China, Taiwan, and South Korea. In 1999, B. xylophilus was discovered in Portugal, and in 2008 in Spain. So far the studies have revealed that the pathogenicity of B. xylophilus varies between different isolates. The conducted study compared the pathogenicity of five isolates of B. xylophilus, originating from different parts of Japan, to 3-year-old Pinus sylvestris, and their ability to reproduce in the seedlings. The results revealed diverse virulence of B. xylophilus resulting in plant mortality. Three isolates S10, Ka4, and T4 caused 100% mortality of plants within three months while at the same time, the other two isolates, C14-5 and OKD-1 did not cause any disease symptoms on plants. After seven months, some dieback occurred on two seedlings, but similar symptoms were also found on the control plant. Moreover, a significant positive correlation was found between nematode virulence and the number of nematodes reproducing on pine seedlings.

scholarly journals Bxy‐fuca encoding α‐L‐fucosidase plays crucial roles in development and reproduction of the pathogenic pinewood nematode, Bursaphelenchus xylophilus

2019 ◽  
Vol 76 (1) ◽  
pp. 205-214 ◽  
Author(s):  
Jia Tang ◽  
Ruoqing Ma ◽  
Najie Zhu ◽  
Kai Guo ◽  
Yiqing Guo ◽  
...  
Keyword(s):  
Bursaphelenchus Xylophilus ◽  
Pinewood Nematode

scholarly journals Genetic characteristics of Bursaphelenchus xylophilus third-stage dispersal juveniles

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Qiaoli Chen ◽  
Ruizhi Zhang ◽  
Danlei Li ◽  
Feng Wang
Keyword(s):  
Fat Metabolism ◽  
Bursaphelenchus Xylophilus ◽  
Pinewood Nematode ◽  
Genetic Characteristics ◽  
Highest Weight ◽  
Homologous Genes ◽  
Third Stage ◽  
Highly Correlated ◽  
Oil Red O Staining ◽  
Oil Red O

AbstractThe third-stage dispersal juvenile (DJ3) of pinewood nematode (PWN) is highly associated with low-temperature survival and spread of the nematode. Oil-Red-O staining showed that its lipid content was significantly higher compared with other PWN stages. Weighted gene coexpression network analysis identified that genes in the pink module were highly related to DJ3 induced in the laboratory (DJ3-lab). These genes were arranged according to their gene significance (GS) to DJ3-lab. Of the top 30 genes with the highest GS, seven were found to be highly homologous to the cysteine protease family cathepsin 1 (CATH1). The top 30 genes with the highest weight value to each of the seven genes in the pink module were selected, and finally 35 genes were obtained. Between these seven CATH1 homologous genes and their 35 highly related genes, 15 were related to fat metabolism or autophagy. These autophagy-related genes were also found to be highly correlated with other genes in the pink module, suggesting that autophagy might be involved in the mechanism of longevity in DJ3 and the formation of DJ3 by regulating genes related to fat metabolism.

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.

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