scholarly journals Understanding pine wilt disease: roles of the pine endophytic bacteria and of the bacteria carried by the disease-causing pinewood nematode

2016 ◽  
Vol 6 (2) ◽  
pp. e00415 ◽  
Author(s):  
Diogo N. Proença ◽  
Gregor Grass ◽  
Paula V. Morais
Keyword(s):  
Endophytic Bacteria ◽  
Pine Wilt Disease ◽  
Wilt Disease ◽  
Pinewood Nematode ◽  
Pine Wilt

scholarly journals Spatiotemporal Pattern of Pine Wilt Disease in the Yangtze River Basin

Forests ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 731
Author(s):  
Zhuoqing Hao ◽  
Jixia Huang ◽  
Yantao Zhou ◽  
Guofei Fang
Keyword(s):  
River Basin ◽  
Yangtze River ◽  
Yangtze River Basin ◽  
Pine Wilt Disease ◽  
Wilt Disease ◽  
Spatiotemporal Pattern ◽  
Pinewood Nematode ◽  
The Yangtze River ◽  
Pine Wilt ◽  
The Yangtze River Basin

The Yangtze River Basin is among the river basins with the strongest strategic support and developmental power in China. As an invasive species, the pinewood nematode (PWN) Bursaphelenchus xylophilus has introduced a serious obstacle to the high-quality development of the economic and ecological synchronization of the Yangtze River Basin. This study analyses the occurrence and spread of pine wilt disease (PWD) with the aim of effectively managing and controlling the spread of PWD in the Yangtze River Basin. In this study, statistical data of PWD-affected areas in the Yangtze River Basin are used to analyse the occurrence and spread of PWD in the study area using spatiotemporal visualization analysis and spatiotemporal scanning statistics technology. From 2000 to 2018, PWD in the study area showed an “increasing-decreasing-increasing” trend, and PWD increased explosively in 2018. The spatial spread of PWD showed a “jumping propagation-multi-point outbreak-point to surface spread” pattern, moving west along the river. Important clusters were concentrated in the Jiangsu-Zhejiang area from 2000 to 2015, forming a cluster including Jiangsu and Zhejiang. Then, from 2015–2018, important clusters were concentrated in Chongqing. According to the spatiotemporal scanning results, PWD showed high aggregation in the four regions of Zhejiang, Chongqing, Hubei, and Jiangxi from 2000 to 2018. In the future, management systems for the prevention and treatment of PWD, including ecological restoration programs, will require more attention.

Spatiotemporal analysis of pine wilt disease: Relationship between pinewood nematode distribution and defence response in Pinus thunbergii seedlings

2019 ◽  
Vol 49 (4) ◽  
pp. e12518 ◽  
Author(s):  
Rimi Yamaguchi ◽  
Koji Matsunaga ◽  
Tomonori Hirao ◽  
Miho Tamura ◽  
Atsushi Watanabe
Keyword(s):  
Pine Wilt Disease ◽  
Spatiotemporal Analysis ◽  
Wilt Disease ◽  
Pinus Thunbergii ◽  
Defence Response ◽  
Pinewood Nematode ◽  
Pine Wilt

Endogenous bacterial community structure of Pinus massoniana with differing resistance to pine wilt disease

Nematology ◽  
2021 ◽  
pp. 1-17
Author(s):  
Wei Lu ◽  
Xiao-Jia Zhao ◽  
Jia-Jin Tan
Keyword(s):  
Disease Resistance ◽  
Bacterial Community ◽  
Endophytic Bacteria ◽  
Pine Wilt Disease ◽  
Illumina Miseq ◽  
Pinus Massoniana ◽  
Wilt Disease ◽  
Pine Wilt ◽  
Disease Resistant ◽  
Endophytic Bacterial Community

Summary Pine wilt disease (PWD) is a devastating pine disease caused by Bursaphelenchus xylophilus and its main host in China is Pinus massoniana. The relationship between endophytic bacteria and disease resistance in P. massoniana remains unclear. In this paper, the leaves, roots, stems and treetops of different disease-resistant P. massoniana were studied as the research objective and Illumina MiSeq sequencing was used to analyse whether there were significant differences in the composition and diversity of endophytic bacterial communities between different disease-resistant P. massoniana. The results showed that at the genus level there were no obvious differences in the composition of the endophytic bacterial community of different disease-resistant P. massoniana in the leaves, but there were obvious differences in the roots, stems and treetops. The richness and diversity of endophytic bacteria in P. massoniana had no significant impact on its disease resistance, whilst the structure of endophytic bacterial community in stems and treetops may be related to its disease resistance.

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 The specialization of Esteya vermicola hyphae in infection to Bursaphelenchus xylophilus and its colonization of pine tree

2020 ◽  
Author(s):  
Hai-Hua Wang ◽  
Can Yin ◽  
Jie Gao ◽  
Ran Tao ◽  
Piao-Piao Dai ◽  
...  
Keyword(s):  
Pine Wilt Disease ◽  
Bursaphelenchus Xylophilus ◽  
Wilt Disease ◽  
Fungal Colonization ◽  
Pinewood Nematode ◽  
Pine Tree ◽  
Pine Wilt ◽  
Pine Trees ◽  
Colonization Patterns ◽  
Esteya Vermicola

AbstractPine wilt disease (PWD) caused by the nematode Bursaphelenchus xylophilus is a serious problem on pines, and there is currently no effective control strategy for this disease. Although the endoparasitic fungus Esteya vermicola showed great effectiveness in controlling pine wilt disease, the colonization patterns of the host pine tree xylem by this fungus are unknown. To investigate the colonization patterns of pine xylem by this fungus, the species Pinus koraiensis grown in a greenhouse was used as an experimental host tree. The fungal colonization of healthy and wilting pine trees by E. vermicola was quantified using PCR with a TaqMan probe, and a green fluorescence protein (GFP) transformant was used for visualization. The results reported a specific infection approach used by E. vermicola to infect B. xylophilus and specialized fungal parasitic cells in PWN infection. In addition, the inoculated blastospores of E. vermicola germinated and grew inside of healthy pine xylem, although the growth rate was slow. Moreover, E. vermicola extended into the pine xylem following spray inoculation of wounded pine seedling stems, and a significant increase in fungal quantity was observed in response to B. xylophilus invasion. An accelerated extension of E. vermicola colonization was shown in PWN-infected wilting pine trees, due to the immigration of fungal-infected PWNs. Our results provide helpful knowledge about the extension rate of this fungus in healthy and wilting PWN-susceptible pine trees in the biological control of PWD and will contribute to the development of a management method for PWD control in the field.Author summaryPine wilt disease, caused by Bursaphelenchus xylophilus, has infected most pine forests in Asian and European forests and led to enormous losses of forest ecosystem and economy. Esteya vermicola is a bio-control fungus against pinewood nematode, showed excellent control efficient to pine wilt disease in both of greenhouse experiments and field tests. Although this bio-control agent was well known for the management of pine wilt disease, the infection mechanism of fungal infection and colonization of host pine tree are less understand. Here, we use GFP-tagged mutant to investigate the fungal infection to pinewood nematode; additionally, the temporal and spatial dynamics of E. vermicola colonize to pine tree were determined by the TaqMan real-time PCR quantification, as well as the response to pinewood nematode invasion. We found a specific infection approach used by E. vermicola to infect B. xylophilus and specialized fungal parasitic cells in PWN infection. In addition, the fungal germination and extension inside of pine tree xylem after inoculation were revealed. In addition, the quantity of E. vermicola increased as response to pinewood nematode invasion was reported. Our study provides two novel technologies for the visualization and detection of E. vermicola for the future investigations of fungal colonization and its parasitism against pinewood nematode, and the mechanisms of the bio-control process.

scholarly journals Characterization of bacterial communities associated with the pinewood nematode insect vector Monochamus alternatus Hope and the host tree Pinus massoniana

2020 ◽  
Author(s):  
Yajie Guo ◽  
Qiannan Lin ◽  
lvyi Chen ◽  
Carballar-Lejarazú Rebeca ◽  
Aishan Zhang ◽  
...  
Keyword(s):  
Pine Wilt Disease ◽  
Wilt Disease ◽  
Insect Vector ◽  
Insect Vectors ◽  
Pinewood Nematode ◽  
Monochamus Alternatus ◽  
Form Complex ◽  
Pine Wilt ◽  
Bacterial Microbiota ◽  
Habitat Niche

Abstract Background: Monochamus alternatus Hope is one of the insect vectors of pinewood nematode (Bursaphelenchus xylophilus), which causes the destructive pine wilt disease. The microorganisms within the ecosystem, comprising plants, their environment, and insect vectors, form complex networks. This study presents a systematic analysis of the bacterial microbiota in the M. alternatus midgut and its habitat niche.Methods: Total DNA was extracted from 20 types of samples (with three replicates each) from M. alternatus and various tissues of healthy and infected P. massoniana (pines). 16S rDNA amplicon sequencing was conducted to determine the composition and diversity of the bacterial microbiota in each sample. Moreover, the relative abundances of bacteria in the midgut of M. alternatus larvae were verified by counting the colony-forming units.Results: Pinewood nematode infection increased the microbial diversity in pines. Bradyrhizobium, Burkholderia, Dyella, Mycobacterium, and Mucilaginibacter were the dominant bacterial genera in the soil and infected pines. These results indicate that the bacterial community in infected pines may be associated with the soil microbiota. Interestingly, the abundance of the genus Gryllotalpicola was highest in the bark of infected pines. The genus Cellulomonas was not found in the midgut of M. alternatus, but it peaked in the phloem of infected pines, followed by the phloem of heathy pines. Moreover, the genus Serratia was not only present in the habitat niche, but it was also enriched in the M. alternatus midgut. The colony-forming unit assays showed that the relative abundance of Serratia sp. peaked in the midgut of instar II larvae (81%).Conclusions: Overall, the results indicate that the bacterial microbiota in the soil and in infected pines are correlated. The Gryllotalpicola sp. and Cellulomonas sp. are potential microbial markers of pine wilt disease. Additionally, Serratia sp. could be an ideal agent for expressing insecticidal protein in the insect midgut by genetic engineering, which represents a new use of microbes to control M. alternatus.

scholarly journals Systemic Acquired Resistance-Mediated Control of Pine Wilt Disease by Foliar Application With Methyl Salicylate

2022 ◽  
Vol 12 ◽  
Author(s):  
Hee Won Jeon ◽  
Ae Ran Park ◽  
Minjeong Sung ◽  
Namgyu Kim ◽  
Mohamed Mannaa ◽  
...  
Keyword(s):  
Methyl Salicylate ◽  
Systemic Acquired Resistance ◽  
Foliar Application ◽  
Acquired Resistance ◽  
Pine Wilt Disease ◽  
Wilt Disease ◽  
Pcr Analysis ◽  
Pinewood Nematode ◽  
Pine Wilt ◽  
Pine Seedlings

Pine wilt disease (PWD), caused by the pinewood nematode, is the most destructive disease in pine forest ecosystems worldwide. Extensive research has been done on PWD, but effective disease management is yet to be devised. Generally, plants can resist pathogen attack via a combination of constitutive and inducible defenses. Systemic acquired resistance (SAR) is an inducible defense that occurs by the localized infection of pathogens or treatment with elicitors. To manage PWD by SAR in pine trees, we tested previously known 12 SAR elicitors. Among them, methyl salicylate (MeSA) was found to induce resistance against PWD in Pinus densiflora seedlings. In addition, the foliar applications of the dispersible concentrate-type formulation of MeSA (MeSA 20 DC) and the emulsifiable concentrate-type formulation of MeSA (MeSA 20 EC) resulted in significantly reduced PWD in pine seedlings. In the field test using 10-year-old P. densiflora trees, MeSA 20 DC showed a 60% decrease in the development of PWD. Also, MeSA 20 EC gave the best results when applied at 0.1 mM concentration 2 and 1 weeks before pinewood nematode (PWN) inoculation in pine seedlings. qRT-PCR analysis confirmed that MeSA induced the expression of defense-related genes, indicating that MeSA can inhibit and delay the migration and reproduction of PWN in pine seedlings by modulating gene expression. These results suggest that foliar application of MeSA could reduce PWD incidence by inducing resistance and provide an economically feasible alternative to trunk-injection agents for PWD management.

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