Impact of Introduction of Arbuscular Mycorrhizal Fungi on the Root Microbial Community in Agricultural Fields

Abstract

Arbuscular mycorrhizal (AM) fungi are important members of the root microbiome and may be used as biofertilizers for sustainable agriculture. To elucidate the impact of AM fungal inoculation on indigenous root microbial communities, we used high-throughput sequencing and an analytical pipeline providing fixed operational taxonomic units (OTUs) as an output to investigate the bacterial and fungal communities of roots treated with a commercial AM fungal inoculum in six agricultural fields. AM fungal inoculation significantly influenced the root microbial community structure in all fields. Inoculation changed the abundance of indigenous AM fungi and other fungal members in a field-dependent manner. Inoculation consistently enriched several bacterial OTUs by changing the abundance of indigenous bacteria and introducing new bacteria. Some inoculum-associated bacteria closely interacted with the introduced AM fungi, some of which belonged to the genera Burkholderia , Cellulomonas , Microbacterium , Sphingomonas , and Streptomyces and may be candidate mycorrhizospheric bacteria that contribute to the establishment and/or function of the introduced AM fungi. Inoculated AM fungi also co-occurred with several indigenous bacteria with putative beneficial traits, suggesting that inoculated AM fungi may recruit specific taxa to confer better plant performance. The bacterial families Methylobacteriaceae , Acetobacteraceae , Armatimonadaceae , and Alicyclobacillaceae were consistently reduced by the inoculation, possibly due to changes in the host plant status caused by the inoculum. To the best of our knowledge, this is the first large-scale study to investigate interactions between AM fungal inoculation and indigenous root microbial communities in agricultural fields.

Soil Quality Indicators Associated With The Application Of Mycorrhizal Fungi In Coffee Plantations

“…Similarly, the results that have been reported indicate that phosphate-solubilizing microorganisms increased significantly in soils with mycorrhizal application; the same results were found by those who claim that phosphate-solubilizing bacteria and mycorrhizae can act synergistically, as phosphate-solubilizing bacteria can increase the amount of phosphorus that is available in the soil, meaning that mycorrhizal inoculation leads to changes in the bacterial composition of the root, as evidenced in this study [33]. Certainly, although the spores that were inoculated in the plot of the mycorrhizae native to the area were lower than those of the solid and liquid application, the behavior of quality parameters of the soil in the study area was significantly higher in the plot with native mycorrhizae, coinciding with the research that reports the efficiency in the inoculation of bacterial consortia with native mycorrhizae, in which the spores, being resistant structures typical of the place, can remain in the soil for a longer period of time compared to the remains of external mycorrhized vegetables, such as in the case of solid and liquid mycorrhizae [37].…”

The Aromatic Plant Clary Sage Shaped Bacterial Communities in the Roots and in the Trace Element-Contaminated Soil More Than Mycorrhizal Inoculation – A Two-Year Monitoring Field Trial

“…The present study focused on the rhizosphere bacterial community, given its contribution in ecosystem functioning and services (Delgado-Baquerizo et al, 2016;Foulon et al, 2016b;Dagher et al, 2019). It is in particular well known that the rhizosphere microbial communities are an important factor influencing plant growth and subsequently biomass and EO production (Wang X. et al, 2018;Akyol et al, 2019;Berlanas et al, 2019).…”

“…In fact, it was previously demonstrated in the case of Eucalyptus or grapevine, that distinct bacterial communities were observed at different plantation ages (Berlanas et al, 2019;Qu et al, 2020). In particular, changes in exudation profiles are susceptible to occur with plant age, at distinct growth stages (Akyol et al, 2019). Similarly, in the case of aromatic plant species, such as M. arvensis or A. annua, the longterm mono-cultivation was brought forward as an explaining factor of bacterial communities' diversity and evenness (Misra et al, 2019).…”

“…It is believed that the distinctive microbiome around aromatic plants is highly specific and dependant on the plant species and on the related nature and abundance of secondary metabolites, present in the root exudates (Köberl et al, 2013;Adamovic et al, 2015;Misra et al, 2019). Apart from the effects of plant's driven changes on microbial communities, it has been previously reported that mycorrhizal inoculation can also influence the microbial community structure (Lioussanne et al, 2010;Akyol et al, 2019;Monokrousos et al, 2019;Dagher et al, 2020a). Soil bacteria may obtain carbon from AMF hyphae exudates or use the hyphae themselves as substrate (Qin et al, 2016;Gui et al, 2017), creating a niche for the growth of specific bacteria (Toljander et al, 2006;Gui et al, 2017).…”

Growth Stage-dependent Bacterial Communities in Soybean Plant Tissues: <i>Methylorubrum</i> Transiently Dominated in the Flowering Stage of the Soybean Shoot

“…However, microbiome research on field-grown plants is also essential for sustainable agriculture (40). These field studies often dealt with snapshots of microbial communities in terms of the plant growth stage because they focused on environmental factors such as fertilizer levels, crop variety/genotype, and location (1, 5, 11, 22, 23). The physiology and morphology of field-grown plants are reported to markedly change during plant growth stages from seedlings to mature plants for harvesting (6, 46, 47).…”