Assessment of differences in ascomycete communities in the rhizosphere of field-grown wheat and potato

Viebahn, Mareike; Veenman, Christiaan; Wernars, K.; Loon, L.C. van; Smit, Edith G.; Bakker, Peter A. H. M.

doi:10.1016/j.femsec.2004.12.014

Cited by 50 publications

(26 citation statements)

References 40 publications

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“…DGGE has been used to analyze fungal communities from a variety of environments (8,9,17,38,40), and here DGGE revealed that only a subset of the fungal species present in either soil were present on the buried PU (Fig. 1).…”

Section: Discussionmentioning

confidence: 93%

Fungal Communities Associated with Degradation of Polyester Polyurethane in Soil

Cosgrove

McGeechan²,

Robson

et al. 2007

Appl Environ Microbiol

156

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Soil fungal communities involved in the biodegradation of polyester polyurethane (PU) were investigated. PU coupons were buried in two sandy loam soils with different levels of organic carbon: one was acidic (pH 5.5), and the other was more neutral (pH 6.7). After 5 months of burial, the fungal communities on the surface of the PU were compared with the native soil communities using culture-based and molecular techniques. Putative PU-degrading fungi were common in both soils, as <45% of the fungal colonies cleared the colloidal PU dispersion Impranil on solid medium. Denaturing gradient gel electrophoresis showed that fungal communities on the PU were less diverse than in the soil, and only a few species in the PU communities were detectable in the soil, indicating that only a small subset of the soil fungal communities colonized the PU. Soil type influenced the composition of the PU fungal communities. Geomyces pannorum and a Phoma sp. were the dominant species recovered by culturing from the PU buried in the acidic and neutral soils, respectively. Both fungi degraded Impranil and represented >80% of cultivable colonies from each plastic. However, PU was highly susceptible to degradation in both soils, losing up to 95% of its tensile strength. Therefore, different fungi are associated with PU degradation in different soils but the physical process is independent of soil type.The worldwide production of synthetic polymers continues to rise, resulting in an increased environmental burden through the generation of plastic waste. More than 140 million tonnes of plastic was produced worldwide in 2001 (34), and the proportion of household plastic waste in the average American home increased from 3 to 5% of total waste in 1969 (15) to more than 30% in 1995 (21) and continues to rise. Many plastics are both physically and chemically robust and cause waste management problems (10). However, several families of plastics undergo biodegradation in the environment, and an understanding of how this degradation occurs may aid in the development of strategies to exploit these processes for waste management purposes.Microorganisms are responsible for the majority of plastic degradation (6), and abiotic factors such as photodegradation or hydrolysis play a very minor role (18,42). Plastics vulnerable to biodegradation include the polyhydroxyalkanoates, polycaprolactone, polylactic acid, polyvinyl chloride (31, 32), and polyester polyurethane (PU). PU is used in a variety of industrial applications, including insulating foams, fibers, and synthetic leather and rubber goods. The presence of ester and urethane linkages in the backbone of PUs makes them susceptible to hydrolysis by enzymes secreted by microorganisms, releasing breakdown products which may act as a carbon source and lead to a weakening of the tensile strength (1,13,22,26,27).Both PU-degrading fungi (5,6,12,32) and bacteria (1, 20, 23) have been isolated from PU, indicating that there are potential reservoirs of PU-degrading organisms widespread in the environment. It...

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Section: Discussionmentioning

confidence: 93%

Fungal Communities Associated with Degradation of Polyester Polyurethane in Soil

Cosgrove

McGeechan²,

Robson

et al. 2007

Appl Environ Microbiol

156

View full text Add to dashboard Cite

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“…Most characterized isolates from each crop were not observed on the other two crops, indicating that composition of Pseudomonas populations differed between these plant species. Plant genotype also affects fungal communities in the rhizosphere, as for example demonstrated by Viebahn et al (2005) for ascomycete communities in the rhizospheres of field-grown potato and wheat Plant defenses have the potential to affect bacterial populations in the rhizosphere by either recruiting beneficial bacteria or actively repressing pathogen proliferation. One of the best-studied examples is the biological control of the fungus Gaeumannomyces graminis var.…”

Section: Plants Affect Their Microbial Rhizosphere Communitymentioning

confidence: 99%

Impact of root exudates and plant defense signaling on bacterial communities in the rhizosphere. A review

Doornbos

Loon

Bakker

2011

Agron. Sustain. Dev.

567

313

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Despite significant advances in crop protection, plant diseases cause a 20% yield loss in food and cash crops worldwide. Therefore, interactions between plants and pathogens have been studied in great detail. In contrast, the interplay between plants and non-pathogenic microorganisms has received scant attention, and differential responses of plants to pathogenic and non-pathogenic microorganisms are as yet not well understood. Plants affect their rhizosphere microbial communities that can contain beneficial, neutral and pathogenic elements. Interactions between the different elements of these communities have been studied in relation to biological control of plant pathogens. One of the mechanisms of disease control is induced systemic resistance (ISR). Studies on biological control of plant diseases have focused on ISR the last decade, because ISR is effective against a wide range of pathogens and thus offers serious potential for practical applications in crop protection. Such applications may however affect microbial communities associated with plant roots and interfere with the functioning of the root microbiota. Here, we review the possible impact of plant defense signaling on bacterial communities in the rhizosphere. To better assess implications of shifts in the rhizosphere microflora we first review effects of root exudates on soil microbial communities. Current knowledge on inducible defense signaling in plants is discussed in the context of recognition and systemic responses to pathogenic and beneficial microorganisms. Finally, the as yet limited knowledge on effects of plant defense on rhizosphere microbial communities is reviewed and we discuss future directions of research that will contribute to unravel the molecular interplay of plants and their beneficial microflora.

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“…For example, T-RFLP has been applied to investigate fungal diversity in agricultural land that was turned into fallow fields (Klamer and Hedlund 2004). DGGE has been used to analyze the effects of different cultivation factors on plant pathogenic Fusarium and arbuscular mycorrhizal fungi communities in asparagus fields (Yergeau et al 2006) or to investigate differences in ascomycetes rhizosphere communities in different crops (Viebahn et al 2005). Furthermore, TGGE and SSCP analyses have been performed to asses and compare structures of soil fungal communities in different forest soils .…”

Section: Analysis Of Community Structuresmentioning

confidence: 99%

“…Sequences may subsequently be identified by similarity searches in public data bases like GenBank or RDP. This approach has been used to describe and compare ascomycete taxa present in the rhizosphere of wheat in monoculture and wheat in rotation with potato (Viebahn et al 2005) or to identify mycorrhizal species present in the rhizoshpere of maize plants (Oliveira et al 2009). Obtained sequence information then may allow for designing primers for a strain-or species-specific PCR detection (see above) (Pesaro and Widmer 2006;Widmer et al 2006).…”

Section: Analysis Of Community Structuresmentioning

confidence: 99%

Molecular ecology of fungal entomopathogens: molecular genetic tools and their applications in population and fate studies

Enkerli

Widmer

2009

BioControl

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The power of molecular genetic techniques to address ecological research questions has opened a distinct interdisciplinary research area collectively referred to as molecular ecology. Molecular ecology combines aspects of diverse research fields like population and evolutionary genetics, as well as biodiversity, conservation biology, behavioural ecology, or species-habitat interactions. Molecular techniques detect specific DNA sequence characteristics that are used as genetic markers to discriminate individuals or taxonomic groups, for instance in analyses of population and community structures, for elucidation of phylogenetic relationships, or for the characterization and monitoring of specific strains in the environment. Here, we summarize the PCR-based molecular techniques used in molecular ecological research on fungal entomopathogens and discuss novel techniques that may have relevance to the studies of entomopathogenic fungi in the future. We discuss the flow chart of the molecular ecology approaches and we highlight some of the critical steps involved. There are still many unresolved questions in the understanding of the ecology of fungal entomopathogens. These include population characteristics and relations of genotypes and habitats as well as hostpathogen interactions. Molecular tools can provide substantial support for ecological research and offer insight into this far inaccessible systems. Application of molecular ecology approaches will stimulate and accelerate new research in the field of entomophathogen ecology.

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Assessment of differences in ascomycete communities in the rhizosphere of field-grown wheat and potato

Cited by 50 publications

References 40 publications

Fungal Communities Associated with Degradation of Polyester Polyurethane in Soil

Fungal Communities Associated with Degradation of Polyester Polyurethane in Soil

Impact of root exudates and plant defense signaling on bacterial communities in the rhizosphere. A review

Molecular ecology of fungal entomopathogens: molecular genetic tools and their applications in population and fate studies

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