scholarly journals Testing of selected Pinus pinaster half-sib families for tolerance to pinewood nematode (Bursaphelenchus xylophilus)

2017 ◽  
Vol 91 (1) ◽  
pp. 38-48 ◽  
Author(s):  
María Menéndez-Gutiérrez ◽  
Margarita Alonso ◽  
Gabriel Toval ◽  
Raquel Díaz
Keyword(s):  
Pinus Pinaster ◽  
Bursaphelenchus Xylophilus ◽  
Pinewood Nematode ◽  
Sib Families

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 Insights Into the Mechanisms Implicated in Pinus pinaster Resistance to Pinewood Nematode

2021 ◽  
Vol 12 ◽  
Author(s):  
Inês Modesto ◽  
Lieven Sterck ◽  
Vicent Arbona ◽  
Aurelio Gómez-Cadenas ◽  
Isabel Carrasquinho ◽  
...  
Keyword(s):  
Cell Wall ◽  
Pinus Pinaster ◽  
Pine Wilt Disease ◽  
Bursaphelenchus Xylophilus ◽  
Pinewood Nematode ◽  
Acetyl Bromide ◽  
Resistance Response ◽  
Transcriptional Changes ◽  
Disease Impact ◽  
Cell Wall Reinforcement

Pine wilt disease (PWD), caused by the plant–parasitic nematode Bursaphelenchus xylophilus, has become a severe environmental problem in the Iberian Peninsula with devastating effects in Pinus pinaster forests. Despite the high levels of this species' susceptibility, previous studies reported heritable resistance in P. pinaster trees. Understanding the basis of this resistance can be of extreme relevance for future programs aiming at reducing the disease impact on P. pinaster forests. In this study, we highlighted the mechanisms possibly involved in P. pinaster resistance to PWD, by comparing the transcriptional changes between resistant and susceptible plants after infection. Our analysis revealed a higher number of differentially expressed genes (DEGs) in resistant plants (1,916) when compared with susceptible plants (1,226). Resistance to PWN is mediated by the induction of the jasmonic acid (JA) defense pathway, secondary metabolism pathways, lignin synthesis, oxidative stress response genes, and resistance genes. Quantification of the acetyl bromide-soluble lignin confirmed a significant increase of cell wall lignification of stem tissues around the inoculation zone in resistant plants. In addition to less lignified cell walls, susceptibility to the pine wood nematode seems associated with the activation of the salicylic acid (SA) defense pathway at 72 hpi, as revealed by the higher SA levels in the tissues of susceptible plants. Cell wall reinforcement and hormone signaling mechanisms seem therefore essential for a resistance response.

scholarly journals Intraspecific variation of anatomical and chemical defensive traits in Maritime pine (Pinus pinaster) as factors in susceptibility to the pinewood nematode (Bursaphelenchus xylophilus)

Trees ◽  
2014 ◽  
Vol 29 (3) ◽  
pp. 663-673 ◽  
Author(s):  
Rafael Zas ◽  
Xoaquín Moreira ◽  
Miguel Ramos ◽  
Marta R. M. Lima ◽  
Marta Nunes da Silva ◽  
...  
Keyword(s):  
Intraspecific Variation ◽  
Pinus Pinaster ◽  
Bursaphelenchus Xylophilus ◽  
Maritime Pine ◽  
Pinewood Nematode

scholarly journals Pinus pinaster Early Hormonal Defence Responses to Pinewood Nematode (Bursaphelenchus xylophilus) Infection

Metabolites ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 227
Author(s):  
Ana M. Rodrigues ◽  
Swen Langer ◽  
Isabel Carrasquinho ◽  
Ed Bergström ◽  
Tony Larson ◽  
...  
Keyword(s):  
Pinus Pinaster ◽  
Current Knowledge ◽  
Acid Methyl Ester ◽  
Pine Wilt Disease ◽  
Bursaphelenchus Xylophilus ◽  
Pinewood Nematode ◽  
Crop Species ◽  
Jasmonic Acid Methyl Ester ◽  
Defence Responses ◽  
Pinus Spp

The pinewood nematode (PWN) is the causal agent of pine wilt disease, a pathology that affects conifer forests, mainly Pinus spp. PWN infection can induce the expression of phytohormone-related genes; however, changes at the early phytohormone level have not yet been explored. Phytohormones are low-abundance metabolites, and thus, difficult to quantify. Moreover, most methodologies focus mainly on Arabidopsis or crop species. This work aimed to validate a fast (run time 6.6 min) liquid chromatography-triple quadrupole tandem mass spectrometry (LC-QqQ-MS/MS) analytical method to quantify 14 phytohormones in Pinus pinaster stem tissues. This method was further applied to evaluate, for the first time, early phytohormone changes in susceptible and resistant phenotypes of P. pinaster 24, 48 and 72 h after inoculation (HAI) with PWN. A significant increase in salicylic acid (SA, 48 and 72 HAI) and jasmonic acid methyl ester (JA-ME, 72 HAI) was observed in susceptible phenotypes. Results indicate that the higher susceptibility of P. pinaster to PWN infection might result from an inefficient trigger of hypersensitive responses, with the involvement of JA and SA pathways. This work provides an important update in forest research, and adds to the current knowledge of Pinus spp. defence responses to PWN infection.

scholarly journals Comparative Analysis of Bursaphelenchus xylophilus Secretome Under Pinus pinaster and P. pinea Stimuli

2021 ◽  
Vol 12 ◽  
Author(s):  
Hugo Silva ◽  
Sandra I. Anjo ◽  
Bruno Manadas ◽  
Isabel Abrantes ◽  
Luís Fonseca ◽  
...  
Keyword(s):  
Pinus Pinaster ◽  
Antioxidant Activities ◽  
Enrichment Analysis ◽  
Bursaphelenchus Xylophilus ◽  
Binding Activity ◽  
Pinewood Nematode ◽  
Susceptible Host ◽  
Proteomic Data ◽  
Theoretical Mass ◽  
Functional Analyses

The pinewood nematode (PWN), Bursaphelenchus xylophilus, the pine wilt disease’s (PWD) causal agent, is a migratory endoparasitic nematode skilled to feed on pine tissues and on fungi that colonize the trees. In order to study B. xylophilus secretomes under the stimulus of pine species with different susceptibilities to disease, nematodes were exposed to aqueous pine extracts from Pinus pinaster (high-susceptible host) and P. pinea (low-susceptible host). Sequential windowed acquisition of all theoretical mass spectra (SWATH-MS) was used to determine relative changes in protein amounts between B. xylophilus secretions, and a total of 776 secreted proteins were quantified in both secretomes. From these, 22 proteins were found increased in the B. xylophilus secretome under the P. pinaster stimulus and 501 proteins increased under the P. pinea stimulus. Functional analyses of the 22 proteins found increased in the P. pinaster stimulus showed that proteins with peptidase, hydrolase, and antioxidant activities were the most represented. On the other hand, gene ontology (GO) enrichment analysis of the 501 proteins increased under the P. pinea stimulus revealed an enrichment of proteins with binding activity. The differences detected in the secretomes highlighted the diverse responses from the nematode to overcome host defenses with different susceptibilities and provide new clues on the mechanism behind the pathogenicity of this plant-parasitic nematode. Proteomic data are available via ProteomeXchange with identifier PXD024011.

scholarly journals Primary Metabolite Adjustments Associated With Pinewood Nematode Resistance in Pinus pinaster

2021 ◽  
Vol 12 ◽  
Author(s):  
Ana M. Rodrigues ◽  
Isabel Carrasquinho ◽  
Carla António
Keyword(s):  
Pinus Pinaster ◽  
Water Status ◽  
Pine Wilt Disease ◽  
Nematode Resistance ◽  
Bursaphelenchus Xylophilus ◽  
Cellular Damage ◽  
Primary Metabolism ◽  
Pinewood Nematode ◽  
Primary Metabolite

The pinewood nematode (PWN) Bursaphelenchus xylophilus is the causal agent of the pine wilt disease (PWD) and represents one of the major threats to conifer forests. The detection of the PWN in Portugal, associated with Pinus pinaster, increased the concern of its spread to European forests. Despite its susceptibility to PWD, genetic variability found among P. pinaster populations has been associated with heritable PWD resistance. Understanding the mechanisms underlying tree resistance constitutes a valuable resource for breeding programs toward more resilient forest plantations. This study investigated changes in anatomy, chlorophyll a fluorescence (ChlF), and primary metabolism in susceptible and resistant P. pinaster half-sib plants, after PWN inoculation. Susceptible plants showed a general shutdown of central metabolism, osmolyte accumulation, photosynthetic inhibition, and a decrease in the plant water status. The ChlF transient rise (OJIP curve) revealed the appearance of L- and K-bands, indicators of environmental stress. In contrast, resistant plants revealed a regulated defense response and were able to restrict PWN migration and cellular damage. Furthermore, the accumulation of γ-aminobutyric acid (GABA) and succinate suggested a role of these metabolites in PWD resistance and the possible activation of the GABA shunt. Altogether, these results provide new insights to the role of primary metabolism in PWD resistance and in the selection of resistant phenotypes for disease mitigation.

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