Endophytic fungal communities of Polygonum acuminatum and Aeschynomene fluminensis are influenced by soil mercury contamination

Abstract

The endophytic fungal communities of Polygonum acuminatum and Aeschynomene fluminensis were examined with respect to soil mercury (Hg) contamination. Plants were collected in places with and without Hg +2 for isolation and identification of their endophytic root fungi. We evaluated frequency of colonization, number of isolates and richness, indices of diversity and similarity, functional traits (hydrolytic enzymes, siderophores, indoleacetic acid, antibiosis and metal tolerance) and growth promotion of Aeschynomene fluminensis inoculated with endophytic fungi on soil with mercury. The frequency of colonization, structure and community function, as well as the abundant distribution of taxa of endophytic fungi were influenced by mercury contamination, with higher endophytic fungi in hosts in soil with mercury. The presence or absence of mercury in the soil changes the profile of the functional characteristics of the endophytic fungal community. On the other hand, tolerance of lineages to multiple metals is not associated with contamination. A. fluminensis depends on its endophytic fungi, since plants free of endophytic fungi grew less than expected due to mercury toxicity. In contrast plants containing certain endophytic fungi showed good growth in soil containing mercury, even exceeding growth of plants cultivated in soil without mercury. The data obtained confirm the hypothesis that soil contamination by mercury alters community structure of root endophytic fungi in terms of composition, abundance and species richness. The inoculation of A. fluminensis with certain strains of stress tolerant endophytic fungi contribute to colonization and establishment of the host and may be used in processes that aim to improve phytoremediation of soils with toxic concentrations of mercury.

Sustainability Agenda for the Pantanal Wetland: Perspectives on a Collaborative Interface for Science, Policy, and Decision-Making

“…In tropical wetlands, the rate of biomagnification of the mercury in the trophic web is high (Da Silva & Estanislau, 2015;Oliveira, Hylander, & e Silva, 2004;Vieira et al, 1995). Signs of this process have been already found in the Pantanal (e.g., Callil & Junk, 2009;Ceccatto et al, 2016;Del Lama, Rocha, Jardim, Tsai, & Frederick, 2011;Fonseca, Malm, & Waldemarin, 2005;Hylander et al, 2000;May Junior et al, 2017;Pietro-Souza et al, 2017;Vieira et al, 2011).…”

Bioprospecting and Structure of Fungal Endophyte Communities Found in the Brazilian Biomes, Pantanal, and Cerrado

“…Diaporthe was the dominant genus in both plants (Figure 3 ; Table S1 ). This genus has also been described as dominant in S. adstringens by Carvalho et al ( 2012 ) and is widely distributed in different plants of several biomes, such as the Pantanal (Hokama et al, 2017 ; Pietro-Souza et al, 2017 ), Mangrove forest (de Souza Sebastianes et al, 2013 ), Atlantic Rainforest (Correia et al, 2017 ), Cerrado and Caatinga (Ferreira et al, 2012 ; Lisboa et al, 2013 ). The ability of Diaporthe species to colonize different plants may result from the produced metabolites that bypass the plants defenses, or even by acting on host development and defense against plant pathogens (Nicoletti and Fiorentino, 2015 ; Santos et al, 2016 ; Tahir et al, 2017 ).…”

Isolation and characterization of mercury-resistant microbes from gold mine area in Mount Pongkor, Bogor District, Indonesia

“…These compounds may bind to metal ions in the soil in certain circumstances (Hamayun et al 2009;Li et al 2020). Even though mercury resistance mechanisms in fungi have not yet been fully elucidated, resistance fungi with the ability to degrade mercury have been reported, such as Cladosporium cladosporioides, which resistant towards Hg +2 because of bio-volatilization as the primary mechanism (Pietro-Souza et al 2017).…”