Interaction between the ectomycorrhizal fungus Paxillus involutus and Pinus resinosa induces resistance to Fusarium oxysporum

1988 ◽  
Vol 66 (3) ◽  
pp. 558-562 ◽  
Author(s):  
Luc C. Duchesne ◽  
R. L. Peterson ◽  
Brian E. Ellis
Keyword(s):  
Fusarium Oxysporum ◽  
Seedling Survival ◽  
Pathogenic Fungus ◽  
Pinus Resinosa ◽  
Ectomycorrhizal Fungus ◽  
Antibiotic Activity ◽  
Disease Suppression ◽  
Paxillus Involutus ◽  
Subsequent Infection ◽  
Fivefold Increase

Inoculation of Pinus resinosa Ait. seedlings with the ectomycorrhizal fungus Paxillus involutus Fr. resulted in a 47% increase in resistance to subsequent infection by the root pathogenic fungus Fusarium oxysporum f.sp. pini as compared with control seedlings. This increase in seedling survival was associated with a sixfold decrease in the sporulation of F. oxysporum in the rhizosphere of seedlings inoculated with Pax. involutus when compared with the rhizosphere of control seedlings. Extraction and bioassay of the seedling rhizosphere and seedling tissues indicated that inoculation with Pax. involutus led to a fivefold increase in antibiotic activity in the rhizosphere of the seedlings treated with Pax. involutus. Most or all of the fungitoxicity was localized in the rhizosphere. Disease suppression by Pax. involutus in P. resinosa is, therefore, associated with an increase of fungitoxic chemicals in the rhizosphere of seedlings.

Disease suppression by the ectomycorrhizal fungus Paxillus involutus: contribution of oxalic acid

1989 ◽  
Vol 67 (9) ◽  
pp. 2726-2730 ◽  
Author(s):  
Luc C. Duchesne ◽  
Brian E. Ellis ◽  
R. L. Peterson
Keyword(s):  
Oxalic Acid ◽  
Root Rot ◽  
High Performance ◽  
Root Exudate ◽  
Gel Filtration ◽  
Pinus Resinosa ◽  
Fold Increase ◽  
Ectomycorrhizal Fungus ◽  
Disease Suppression ◽  
Paxillus Involutus

Seedlings of Pinus resinosa Ait. grown in test tubes were inoculated with the ectomycorrhizal fungus Paxillus involutus Fr. Oxalic acid was identified as one of the ethanol-soluble fungistatic and (or) fungitoxic components of the rhizosphere after fractionation by high performance liquid chromatography, paper chromatography, and gel filtration. Simultaneous inoculation of P. resinosa seedlings with authentic oxalic acid and a spore suspension of Fusarium oxysporum f.sp. pini protected the seedlings against Fusarium root rot and decreased the sporulation of F. oxysporum in the rhizosphere when compared with controls lacking oxalic acid. Quantitation of oxalic acid showed a five fold increase in production by Pax. involutus in tubes containing P. resinosa seedlings when compared with tubes lacking seedlings. The synthesis of oxalic acid by Pax. involutus is, therefore, stimulated by P. resinosa root exudate.

Early effects of the ectomycorrhizal fungus Paxillus involutus on the root rot organism Fusarium associated with Pinus resinosa

1990 ◽  
Vol 68 (7) ◽  
pp. 1589-1596 ◽  
Author(s):  
M. L. Farquhar ◽  
R. L. Peterson
Keyword(s):  
Pinus Resinosa ◽  
Ectomycorrhizal Fungus ◽  
Test Tube ◽  
Disease Suppression ◽  
Wall Material ◽  
Paxillus Involutus ◽  
Calcofluor White ◽  
Cytoplasmic Inclusions ◽  
Early Effects ◽  
Root Tissues

Infection of Pinus resinosa Ait. seedlings in a sterile test tube culture system by Fusarium oxysporum f.sp. pini Schlecht. emend. Snyd. & Hans., which was determined microscopically by the presence of the fungus within root tissues, was significantly reduced within the first 6 days of infection after prior inoculation with the ectomycorrhizal fungus Paxillus involutus (Batsch) Fr. Hyphae and conidia of the pathogen were swollen and filled with osmiophilic material when P. involutus was also present in the rhizosphere of P. resinosa seedlings. Germination of F. oxysporum conidia was suppressed when they were placed in holes in P. involutus cultures on modified Melin Norkrans medium in Petri plates but was restored with removal of conidia from plates. Suppressed, ungerminated conidia had thick cell walls and large cytoplasmic inclusions. Staining using Calcofluor White M2R New revealed changes in the binding properties of septal wall material. Key words: Paxillus, Fusarium, ectomycorrhiza, disease suppression, anatomy.

Later events in suppression of Fusarium root rot of red pine seedlings by the ectomycorrhizal fungus Paxillus involutus

1991 ◽  
Vol 69 (6) ◽  
pp. 1372-1383 ◽  
Author(s):  
M. L. Farquhar ◽  
R. L. Peterson
Keyword(s):  
Pinus Resinosa ◽  
Ectomycorrhizal Fungus ◽  
Red Pine ◽  
Disease Suppression ◽  
Host Cells ◽  
Paxillus Involutus ◽  
Free System ◽  
Primary Roots ◽  
Pine Seedlings ◽  
Rooting Medium

Colonization of primary roots of red pine (Pinus resinosa Ait.) seedlings by two isolates of the fungal pathogen Fusarium oxysporum Schlecht. emend Snyd. & Hans. f.sp. pini in a sterile, soil-free system and a nonsterile rooting medium was suppressed for 2 months if the roots were exposed to the ectomycorrhizal fungus Paxillus involutus (Batsch.) Fr. for 1 week before being inoculated with the pathogen. Roots of protected seedlings harboured only a few hyphae of the pathogen. These were either vacuolated or filled with slightly electron-dense substances and did not penetrate host cells. In contrast, roots of seedlings not inoculated by P. involutus were extensively colonized by F. oxysporum, and host tissue vacuolation and disorganization occurred. Papillae, consisting of either small protuberances or elongate projections, were infrequently formed in response to infection. Chlamydospores of F. oxysporum that formed in the sterile system had numerous lipid deposits and amorphous thick walls but few mitochondria and little endoplasmic reticulum. Key words: biological control, ectomycorrhiza, Fusarium, Pinus resinosa, disease suppression.

scholarly journals The sss Colonization Gene of the Tomato-Fusarium oxysporum f. sp. radicis-lycopersici Biocontrol Strain Pseudomonas fluorescens WCS365 Can Improve Root Colonization of Other Wild-type Pseudomonas spp. Bacteria

2000 ◽  
Vol 13 (11) ◽  
pp. 1177-1183 ◽  
Author(s):  
Linda C. Dekkers ◽  
Ine H. M. Mulders ◽  
Claartje C. Phoelich ◽  
Thomas F. C. Chin-A-Woeng ◽  
André H. M. Wijfjes ◽  
...  
Keyword(s):  
Fusarium Oxysporum ◽  
Pseudomonas Fluorescens ◽  
Pathogenic Fungus ◽  
Cell Types ◽  
Disease Suppression ◽  
Systemic Resistance ◽  
Root Tip ◽  
Wild Type ◽  
Tomato Root ◽  
Colonization Ability

We show that the disease tomato foot and root rot caused by the pathogenic fungus Fusarium oxysporum f. sp. radicis-lycopersici can be controlled by inoculation of seeds with cells of the efficient root colonizer Pseudomonas fluorescens WCS365, indicating that strain WCS365 is a bio-control strain. The mechanism for disease suppression most likely is induced systemic resistance. P. fluorescens strain WCS365 and P. chlororaphis strain PCL1391, which acts through the production of the antibiotic phenazine-1-carboxamide, were differentially labeled using genes encoding autofluorescent proteins. Inoculation of seeds with a 1:1 mixture of these strains showed that, at the upper part of the root, the two cell types were present as microcolonies of either one or both cell types. Microcolonies at the lower root part were predominantly of one cell type. Mixed inoculation tended to improve biocontrol in comparison with single inoculations. In contrast to what was observed previously for strain PCL1391, mutations in various colonization genes, including sss, did not consistently decrease the biocontrol ability of strain WCS365. Multiple copies of the sss colonization gene in WCS365 improved neither colonization nor biocontrol by this strain. However, introduction of the sss-containing DNA fragment into the poor colonizer P. fluorescens WCS307 and into the good colonizer P. fluorescens F113 increased the competitive tomato root tip colonization ability of the latter strains 16- to 40-fold and 8- to 16-fold, respectively. These results show that improvement of the colonization ability of wild-type Pseudomonas strains by genetic engineering is a realistic goal.

Effects of Hebeloma arenosa on growth and survival of container-grown red pine seedlings (Pinus resinosa)

1991 ◽  
Vol 21 (10) ◽  
pp. 1459-1465 ◽  
Author(s):  
J. S. MacFall ◽  
S. A. Slack
Keyword(s):  
Seedling Survival ◽  
Pinus Resinosa ◽  
Ectomycorrhizal Fungus ◽  
Commercial Production ◽  
Red Pine ◽  
Shoot Height ◽  
Growth And Survival ◽  
Fungal Inoculum ◽  
Pine Seedlings ◽  
Production Conditions

The ability of the ectomycorrhizal fungus Hebelomaarenosa Burdsall, MacFall & Albers to enhance growth and survival of container-grown red pine seedlings (Pinusresinosa Ait.) was investigated. Shoot height of H. arenosa inoculated seedlings was 28% greater than noninoculated seedlings when grown without fertilizer applications. Eight-week-old seedlings transplanted into a Ball mix (a mixture of peat, bark, and perlite) containing up to a 1:64 dilution of fungal inoculum had significantly greater root dry weights and root/shoot ratios than noninoculated seedlings when grown for an additional 14 weeks. Under experimental greenhouse conditions, root and shoot dry weights of container-grown red pine seedlings that had been directly seeded into Ball mix containing up to a 1:256 dilution of fungal inoculum were significantly greater than weights measured for noninoculated seedlings. Root and shoot dry weights of container-grown seedlings seeded directly into a 1:5 dilution of H. arenosa inoculum and Ball mix and then grown under commercial production conditions were greater than comparable weights of noninoculated seedlings. Hebelomaarenosa inoculation significantly increased seedling survival following outplanting, but did not increase seedling growth. Hebelomaarenosa did not colonize roots growing from the root plug into the surrounding soil.

scholarly journals Development of specific primers for Fusarium oxysporum causing damping off of Lilium formolongi

2020 ◽  
Vol 18 (1) ◽  
Author(s):  
Takeshi Toda ◽  
Shun Hanesaka ◽  
Kuniaki Shishido ◽  
Shin-ichi Fuji ◽  
Hiromitsu Furuya
Keyword(s):  
Fusarium Oxysporum ◽  
Pathogenic Fungus ◽  
Primer Design ◽  
Damping Off ◽  
Specific Primers ◽  
Forma Specialis

AbstractPrimers specific for the hypothetical forma specialis of Fusarium oxysporum were designed to amplify DNA from this pathogenic fungus that infects plants including lilies. The F. oxysporum sequence between the transposal elements han and hop was used for primer design. Three primer pairs designed from this region were confirmed as specific for 24 isolates of F. oxysporum pathogenic to lilies, except for one pathogenic isolates as extraordinary. No amplification was observed from F. oxysporum non-pathogenic to lily, from 12 forma specialis, and 14 fungi and oomycetes concerned with Liliaceae plants. We propose that specific primers designed from this region will be useful to detect isolates of F. oxysporum that are pathogenic to lilies.

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