A Parasite’s Paradise: Biotrophic Species Prevail Oomycete Community Composition in Tree Canopies

Oomycetes (Stramenopiles, protists) are among the most severe plant pathogens,
comprising species with a high economic and ecologic impact on forest ecosystems.
Their diversity and community structures are well studied in terrestrial habitats, but
tree canopies as huge and diverse habitats have been widely neglected. A recent
study highlighted distinct oomycete communities in the canopy stratum compared to
the ground region of three temperate deciduous trees (Quercus robur, Tilia cordata,
Fraxinus excelsior). While the communities from the two strata were distinct when
taking oomycete abundances into account, they were rather similar when only OTU
presence/absence was considered. It remains, however, unknown if this homogeneity
in the OTU presence also leads to a functional homogenisation among microhabitats
within the two strata ground and canopy. In this study, we supplemented functional
traits to oomycete communities in the tree microhabitats, which were determined
over a time period of 2 years with a metabarcoding approach. Our results showed
that even though most oomycetes occurred in all microhabitats, a strong discrepancy
between the strata and correspondingly the distribution of oomycete lifestyles could
be observed. This pattern was constant over several seasons. Obligate biotrophic
species, exclusively feeding on living host tissue, dominated the canopy region,
implying tree canopies to be a hitherto neglected reservoir for parasitic protists. OTUs
assigned to the genus Hyaloperonospora—parasites highly specialised on hosts that
were not sampled—could be determined in high abundances in the canopy and the
surrounding air, challenging the strict host dependencies ruled for some oomycetes.
Our findings further contribute to the understanding of oomycete ecosystem functioning
in forest ecosystems

Identiferoai:union.ndltd.org:DRESDEN/oai:qucosa:de:qucosa:88566
Date11 December 2023
CreatorsJauss, Robin-Tobias, Walden, Susanne, Fiore-Donno, Anna Maria, Schaffer, Stefan, Wolf, Ronny, Feng, Kai, Bonkowski, Michael, Schlegel, Martin
PublisherFrontiers Media S.A.
Source SetsHochschulschriftenserver (HSSS) der SLUB Dresden
LanguageEnglish
Detected LanguageEnglish
Typeinfo:eu-repo/semantics/publishedVersion, doc-type:article, info:eu-repo/semantics/article, doc-type:Text
Rightsinfo:eu-repo/semantics/openAccess
Relation2624-893X, 10.3389/ffgc.2021.668895

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