DNA-barcoding identification of Dothistroma septosporum on Pinus contorta var. latifolia, P. banksiana and their hybrid in northern Alberta, Canada

Seedlings from three conifer species (Pinus contorta Doug. ex Loud. var. latifolia Englem., Picea glauca (Moench) Voss, and Picea mariana (Mill.) BSP) were planted on two clear-cut sites in Alberta, Canada, after inoculation in the nursery with strains of six different ectomycorrhizal species (Hebeloma longicaudum, Laccaria bicolor,Paxillus involutus,Pisolithus tinctorius,Rhizopogon vinicolor, and Suillus tomentosus). Five and 6 years after planting, morphological characterization and molecular typing techniques (internal transcribed spacer restriction fragment length polymorphism (ITS-RFLP) and simple sequence repeat (SSR) markers) were used to identify the ectomycorrhizal fungal communities and to assess the occurrence of the inoculated ectomycorrhizal fungi on host roots. Ectomy corrhi zae recovered from the roots of the planted trees on each of the two sites showed little diversity, with a total of 16 and 19 ITS-RFLP patterns corresponding to 11 and 13 ectomycorrhizal taxa, respectively. The most abundant ectomycorrhizal fungi found on colonized roots were ascomycetes and the widespread basidiomycete Amphinema byssoides. Amongst the six introduced fungal strains, only L. bicolor UAMH 8232 was detected on one site after 5 and 6 years, as determined using six SSR markers. Although not detected after 5 years, some of the introduced strains might have had a positive effect on the early growth of the trees before their replacement by competing species, because significant differences in plot volume index were detected between inoculation and control treatments.

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Comparative Gene Expression Analysis Reveals Mechanism of Pinus contorta Response to the Fungal Pathogen Dothistroma septosporum

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi-10-20-0282-r ◽

2020 ◽

Author(s):

Mengmeng Lu ◽

Nicolas Feau ◽

Dragana Obreht Vidakovic ◽

Nicholas Ukrainetz ◽

Barbara Wong ◽

...

Keyword(s):

Gene Expression ◽

Fungal Pathogen ◽

Pinus Contorta ◽

Lodgepole Pine ◽

Selective Constraint ◽

Transcriptomic Response ◽

Gene Expression Response ◽

Gene Modules ◽

Expression Response ◽

Dothistroma Septosporum

Many conifers have distributions that span wide ranges in both biotic and abiotic conditions, but the basis of response to biotic stress has received much less attention than response to abiotic stress. In this study, we investigated the gene expression response of lodgepole pine (Pinus contorta) to attack by the fungal pathogen Dothistroma septosporum, which causes Dothistroma needle blight (DNB), a disease that has caused severe climate-related outbreaks in northwestern British Columbia. We inoculated tolerant and susceptible pines with two D. septosporum isolates and analyzed the differentially expressed genes, differential exon usage, and co-expressed gene modules using RNA-seq data. We found a rapid and strong transcriptomic response in tolerant lodgepole pine samples inoculated with one D. septosporum isolate, and a late and weak response in susceptible samples inoculated with another isolate. We mapped 43 of the DEG- or gene-module-identified genes to the reference plant-pathogen interaction pathway deposited in KEGG database. These genes are present in PAMP-triggered and effector-triggered immunity pathways. Genes comprising pathways and gene modules had signatures of strong selective constraint, while the highly expressed genes in tolerant samples appear to have been favored by selection to counterattack the pathogen. We identified candidate resistance genes that may respond to D. septosporum effectors. Taken together, our results show that gene expression response to D. septosporum infection in lodgepole pine varies both among tree genotypes and pathogen strains, and involves both known candidate genes and a number of genes with previously unknown functions.

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Warmer and wetter might not be better

Journal of Forest Science ◽

10.17221/18/2014-jfs ◽

2014 ◽

Vol 60 (No. 11) ◽

pp. 484-486 ◽

Cited By ~ 2

Author(s):

A.J. Woods

Keyword(s):

Native Species ◽

Pinus Contorta ◽

Forest Health ◽

Blister Rust ◽

Host Trees ◽

Host Pathogen ◽

Primary Driver ◽

Dothistroma Needle Blight ◽

Dothistroma Septosporum ◽

Needle Blight

As the climate continues to change, gaps in our understanding of how the altered environment will affect forest hosts and their pathogens widen. In some areas pathogens thought to be present for centuries are changing their behaviour. Dothistroma needle blight caused by the fungus Dothistroma septosporum in northwest British Columbia (BC), Canada, is a good example. In this area both the pathogen and the host, lodgepole pine (Pinus contorta var. latifolia), are considered native species, but here Dothistroma has been responsible for killing mature host trees, which is unprecedented. A plausible link between warmer, wetter summers and directional climate change has been suggested as the primary driver. Those environmental conditions appear to be affecting the host/pathogen relationship for other diseases in the neighbouring central interior of BC including comandra blister rust (Cronartium comandrae). Disrupted host/pathogen relationships tend to favour the short-lived more adaptable pathogens rather than their long-lived hosts. These changes in forest health have not been well accounted for in fields of forest science that have been built on stability and predictability.    

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Rapid detection of several endangered agarwood-producing Aquilaria species and their potential adulterants using plant DNA barcodes coupled with high-resolution melting (Bar-HRM) analysis

Holzforschung ◽

10.1515/hf-2018-0149 ◽

2019 ◽

Vol 73 (5) ◽

pp. 435-444 ◽

Cited By ~ 2

Author(s):

Shiou Yih Lee ◽

Dhilia Udie Lamasudin ◽

Rozi Mohamed

Keyword(s):

High Resolution ◽

Dna Barcoding ◽

Pinus Contorta ◽

High Resolution Melting ◽

Cocos Nucifera ◽

Santalum Album ◽

Species Origin ◽

Illegal Harvesting ◽

Counterfeit Products ◽

Species Specific

Abstract Aquilaria is an endangered agarwood-producing genus that is currently protected by international laws. The agarwood trade is strictly monitored to prevent illegal harvesting, which has caused high demand for this natural product. Other plant sources of similar appearance or fragrance as agarwood are used as adulterant species in counterfeit products. To promote species identification via the DNA barcoding technique, the existing DNA barcoding database in our laboratory was enriched with seven plant barcoding sequences from a commercially important Aquilaria species (Aquilaria beccariana) and seven adulterant species (Cocos nucifera, Dalbergia latifolia, Pinus contorta var. latifolia, Santalum album, Strychnos ignatii, Thuja sp. and Terminalia catappa). DNA barcoding with high-resolution melting analysis (Bar-HRM) showed that the mini-barcode internal transcribed spacer 1 (ITS1) was an effective gene locus that allows for a rapid and species-specific detection of Aquilaria and their adulterants, while four other mini-barcodes (rbcL, trnL intron, ITS2 and 5.8s) functioned as a support and a crosscheck for the barcoding results. The accuracy of the Bar-HRM technique in species origin identification was further assessed with seven agarwood blind specimens. The Bar-HRM technique is a potential tool for validating agarwood-species origin and detecting products with adulterant species.

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