AM fungal communities inhabiting the roots of submerged aquatic plant Lobelia dortmanna are diverse and include a high proportion of novel taxa

Abstract

While the arbuscular mycorrhizal (AM) symbiosis is known to be widespread in terrestrial ecosystems, there is growing evidence that aquatic plants also form the symbiosis. It has been suggested that symbiosis with AM fungi may represent an important adaptation for isoëtid plants growing on nutrient-poor sediments in oligotrophic lakes. In this study, we address AM fungal root colonization intensity, richness and community composition (based on small subunit (SSU) ribosomal RNA (rRNA) gene sequencing) in five populations of the isoëtid plant species Lobelia dortmanna inhabiting oligotrophic lakes in Southern Sweden. We found that the roots of L. dortmanna hosted rich AM fungal communities and about 15 % of the detected molecular taxa were previously unrecorded. AM fungal root colonization intensity and taxon richness varied along an environmental gradient, being higher in oligotrophic and lower in mesotrophic lakes. The overall phylogenetic structure of this aquatic fungal community differed from that described in terrestrial systems: The roots of L. dortmanna hosted more Archaeosporaceae and fewer Glomeraceae taxa than would be expected based on global data from terrestrial AM fungal communities.

Arbuscular mycorrhizal fungi communities from tropical Africa reveal strong ecological structure

“…Flooding affects soil fertility and imposes major constraints for germination and growth of flood-intolerant species, thus influencing the composition of plant communities (Jackson & Colmer, 2005). Intense floods may also have a significant detrimental effect on AMF richness and root colonization levels (Miller & Jastrow, 2000;Wang et al, 2011), although some AMF can grow in aquatic habitats such as freshwater lakes (Nielsen et al, 2004;Sudova et al, 2015;Moora et al, 2016), mangroves (Wang et al, 2011) and periodically flooded fields (Watanarojanaporn et al, 2013). However, the effect of periodic flooding in AMF diversity is little understood and could act as an environmental filter for AMF communities in the studied floodplains.…”

Dynamics of oxygen and carbon dioxide in rhizospheres of Lobelia dortmanna – a planar optode study of belowground gas exchange between plants and sediment

“…This may alter the rhizosphere conditions and processes relative to natural conditions in the field. For instance, the root‐associated microbial community would temporarily be disturbed, as would the interaction of roots and mycorrhizal fungi (Moora et al ., ). This may affect the magnitude of rhizosphere oxygenation and CO 2 accumulation, causing a divergence between the experimental and natural conditions.…”

Plant functional groups associate with distinct arbuscular mycorrhizal fungal communities

“…We collated 14 data sets that used similar sampling and molecular approaches to generate information on AM fungi present in the roots of plant individuals, based on 454‐sequencing of the small subunit (SSU) rRNA gene: Moora et al . (), Öpik et al (), Saks et al (), Davison et al (), Gazol et al (), Moora et al (), Koorem et al (), Pärtel et al (), Vasar et al (), Davison et al (), García de León et al (), Sepp et al (), Sepp et al () and L. Neuenkamp et al . (unpublished).…”