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Resistance to Dutch elm disease reduces presence of xylem endophytic fungi in Elms (Ulmus spp.).

Martín JA, Witzell J, Blumenstein K, Rozpedowska E, Helander M, Sieber TN, Gil L - PLoS ONE (2013)

Bottom Line: Efforts to introduce pathogen resistance into landscape tree species by breeding may have unintended consequences for fungal diversity.The resistant and susceptible genotypes could be discriminated on the basis of the phenolic profile of the xylem, but not on basis of phenolics in the leaves or bark.We discuss a potential trade-off between the benefits of breeding resistance into tree species, versus concomitant losses of fungal endophytes and the ecosystem services they provide.

View Article: PubMed Central - PubMed

Affiliation: Departamento de Silvopascicultura, Escuela Técnica Superior de Ingenieros de Montes, Universidad Politécnica de Madrid, Madrid, Spain.

ABSTRACT
Efforts to introduce pathogen resistance into landscape tree species by breeding may have unintended consequences for fungal diversity. To address this issue, we compared the frequency and diversity of endophytic fungi and defensive phenolic metabolites in elm (Ulmus spp.) trees with genotypes known to differ in resistance to Dutch elm disease. Our results indicate that resistant U. minor and U. pumila genotypes exhibit a lower frequency and diversity of fungal endophytes in the xylem than susceptible U. minor genotypes. However, resistant and susceptible genotypes showed a similar frequency and diversity of endophytes in the leaves and bark. The resistant and susceptible genotypes could be discriminated on the basis of the phenolic profile of the xylem, but not on basis of phenolics in the leaves or bark. As the Dutch elm disease pathogen develops within xylem tissues, the defensive chemistry of resistant elm genotypes thus appears to be one of the factors that may limit colonization by both the pathogen and endophytes. We discuss a potential trade-off between the benefits of breeding resistance into tree species, versus concomitant losses of fungal endophytes and the ecosystem services they provide.

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Location of the two study areas in central Spain.
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pone-0056987-g001: Location of the two study areas in central Spain.

Mentions: Elms from two sites in the vicinity of Madrid, Spain were studied (Fig. 1). The first site is located at the Forest Breeding Centre in Puerta de Hierro (40°27′N, 3°46′W), and comprises 205 elm clones randomly planted with a spacing of 4×4 m in a conservation plot (152×36 m) with uniform microclimatic conditions. Each clone was represented by a single 14-year-old ramet. The distance between the selected clones ranged from 16 to 100 m, without any spatial grouping among resistant and susceptible clones. For our study, four U. minor and two U. pumila clones with low susceptibility to DED were selected (hereafter referred to as resistant clones), along with four U. minor clones that are highly susceptible to DED (susceptible clones; Table 1). The number of clones selected for study was determined by the availability of resistant trees (U. minor and U. pumila) of the same age and information of their different genetic background [31], [32]. The soil has a sandy loam texture and was amended annually with organic matter to enhance moisture retention. The plot was irrigated by sprinklers during spring and summer to avoid water stress.


Resistance to Dutch elm disease reduces presence of xylem endophytic fungi in Elms (Ulmus spp.).

Martín JA, Witzell J, Blumenstein K, Rozpedowska E, Helander M, Sieber TN, Gil L - PLoS ONE (2013)

Location of the two study areas in central Spain.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3585289&req=5

pone-0056987-g001: Location of the two study areas in central Spain.
Mentions: Elms from two sites in the vicinity of Madrid, Spain were studied (Fig. 1). The first site is located at the Forest Breeding Centre in Puerta de Hierro (40°27′N, 3°46′W), and comprises 205 elm clones randomly planted with a spacing of 4×4 m in a conservation plot (152×36 m) with uniform microclimatic conditions. Each clone was represented by a single 14-year-old ramet. The distance between the selected clones ranged from 16 to 100 m, without any spatial grouping among resistant and susceptible clones. For our study, four U. minor and two U. pumila clones with low susceptibility to DED were selected (hereafter referred to as resistant clones), along with four U. minor clones that are highly susceptible to DED (susceptible clones; Table 1). The number of clones selected for study was determined by the availability of resistant trees (U. minor and U. pumila) of the same age and information of their different genetic background [31], [32]. The soil has a sandy loam texture and was amended annually with organic matter to enhance moisture retention. The plot was irrigated by sprinklers during spring and summer to avoid water stress.

Bottom Line: Efforts to introduce pathogen resistance into landscape tree species by breeding may have unintended consequences for fungal diversity.The resistant and susceptible genotypes could be discriminated on the basis of the phenolic profile of the xylem, but not on basis of phenolics in the leaves or bark.We discuss a potential trade-off between the benefits of breeding resistance into tree species, versus concomitant losses of fungal endophytes and the ecosystem services they provide.

View Article: PubMed Central - PubMed

Affiliation: Departamento de Silvopascicultura, Escuela Técnica Superior de Ingenieros de Montes, Universidad Politécnica de Madrid, Madrid, Spain.

ABSTRACT
Efforts to introduce pathogen resistance into landscape tree species by breeding may have unintended consequences for fungal diversity. To address this issue, we compared the frequency and diversity of endophytic fungi and defensive phenolic metabolites in elm (Ulmus spp.) trees with genotypes known to differ in resistance to Dutch elm disease. Our results indicate that resistant U. minor and U. pumila genotypes exhibit a lower frequency and diversity of fungal endophytes in the xylem than susceptible U. minor genotypes. However, resistant and susceptible genotypes showed a similar frequency and diversity of endophytes in the leaves and bark. The resistant and susceptible genotypes could be discriminated on the basis of the phenolic profile of the xylem, but not on basis of phenolics in the leaves or bark. As the Dutch elm disease pathogen develops within xylem tissues, the defensive chemistry of resistant elm genotypes thus appears to be one of the factors that may limit colonization by both the pathogen and endophytes. We discuss a potential trade-off between the benefits of breeding resistance into tree species, versus concomitant losses of fungal endophytes and the ecosystem services they provide.

Show MeSH
Related in: MedlinePlus