Host ancestry and morphology differentially influence bacterial and fungal community structure of Rhododendron leaves, roots, and soil

Botany ◽  
2021 ◽  
Author(s):  
Juliana S Medeiros ◽  
Michael A Mann ◽  
Jean H. Burns ◽  
Sarah Kyker ◽  
David Burke

Rhododendron are popular ornamental plants which are well-known for forming mycorrhizal associations with ericoid fungi, but little is known about how host traits influence their microbiome more broadly. This study investigated leaf, root, rhizosphere soil, and bulk soil bacterial and fungal community structure for 12 Rhododendron species, representing four taxonomic clades with different leaf habits. Samples were collected when ephemeral hair roots colonized by ericoid mycorrhizae were absent, and microbial community structure was compared to leaf and root morphology for the same plants. Root morphology and the fungal communities of roots and rhizosphere soil were primarily structured by host ancestry. Leaf bacterial and fungal communities were even more distinct across clades than for roots or rhizosphere, and microbial communities of leaves and bulk soil were similarly structured by clade-wise differences in leaf morphology, suggesting a role for Rhododendron leaf litter in belowground microbial community structure. This work sheds new light on host traits influencing microbial community structure of ericaceous plants, showing a strong influence of ancestry, but also that different host traits drive bacterial and fungal communities across different plant compartments, suggesting future work on factors that drive similarity among close relatives in the non-ericoid microbes associating with Rhododendron.

2020 ◽  
Author(s):  
Ruth Schmidt ◽  
Xiao-Bo Wang ◽  
Paolina Garbeva ◽  
Étienne Yergeau

AbstractNitrapyrin is one of the most common nitrification inhibitors that are used to retain N in the ammonia form in soil to improve crop yields and quality. Whereas the inhibitory effect of nitrapyrin is supposedly specific to ammonia oxidizers, in view of the keystone role of this group in soils, nitrapyrin could have far-reaching impacts. Here, we tested the hypothesis that nitrapyrin leads to large shifts in soil microbial community structure, composition, diversity and functions, beyond its effect on ammonia-oxidizers. To test this hypothesis, we set-up a field experiment where wheat (Triticum aestivum cv. AC Walton) was fertilized with ammonium nitrate (NH4NO3) and supplemented or not with nitrapyrin. Rhizosphere and bulk soils were sampled twice, DNA was extracted, the 16S rRNA gene and ITS region were amplified and sequenced to follow shifts in archaeal, bacterial and fungal community structure, composition and diversity. To assess microbial functions, several genes involved in the nitrogen cycle were quantified by real-time qPCR and volatile organic compounds (VOCs) were trapped in the rhizosphere at the moment of sampling. As expected, sampling date and plant compartment had overwhelming effects on the microbial communities. However, within these strong effects, we found statistically significant effects of nitrapyrin on the relative abundance of Thaumarchaeota, Proteobacteria, Nitrospirae and Basidiomycota, and on several genera. Nitrapyrin also significantly affected bacterial and fungal community structure, and the abundance of all the N-cycle gene tested, but always in interaction with sampling date. In contrast, nitrapyrin had no significant effect on the emission of VOCs, where only sampling date significantly influenced the profiles observed. Our results point out far-reaching effects of nitrapyrin on soil and plant associated microbial communities, well beyond its predicted direct effect on ammonia-oxidizers. In the longer term, these shifts might counteract the positive effect of nitrapyrin on crop nutrition and greenhouse gas emissions.


2021 ◽  
Vol 12 ◽  
Author(s):  
Chao Ji ◽  
Xiaohui Wang ◽  
Xin Song ◽  
Qisheng Zhou ◽  
Chaohui Li ◽  
...  

Plant growth-promoting bacteria (PGPB) can effectively reduce salt damage in plants. Currently, there are many studies on the effects of PGPB on the microbial community structure of rhizosphere soil under salt stress, but fewer studies on the community structure of endophytic bacteria and fungi. We propose that inoculation of endophytic bacteria into the rhizosphere of plants can significantly affect the microbial community structure of the plant’s above-ground and underground parts, which may be the cause of the plant’s “Induced Systemic Tolerance.” The isolated endophytes were re-inoculated into the rhizosphere under salinity stress. We found that, compared with the control group, inoculation with endophytic Bacillus velezensis JC-K3 not only increased the accumulation of wheat biomass, but also increased the content of soluble sugar and chlorophyll in wheat, and reduced the absorption of Na in wheat shoots and leaves. The abundance of bacterial communities in shoots and leaves increased and the abundance of fungal communities decreased after inoculation with JC-K3. The fungal community richness of wheat rhizosphere soil was significantly increased. The diversity of bacterial communities in shoots and leaves increased, and the richness of fungal communities decreased. JC-K3 strain improved wheat’s biomass accumulation ability, osmotic adjustment ability, and ion selective absorption ability. In addition, JC-K3 significantly altered the diversity and abundance of endophytic and rhizosphere microorganisms in wheat. PGPB can effectively reduce plant salt damage. At present, there are many studies on the effect of PGPB on the microbial community structure in rhizosphere soil under salt stress, but there are few studies on the community structure changes of endophytic bacteria and fungi in plants.


2021 ◽  
Vol 12 ◽  
Author(s):  
Jie Cai ◽  
Jie Zhang ◽  
Yun Ding ◽  
Shan Yu ◽  
Hongxin Lin ◽  
...  

Soil microbes play an important role in the ecosystem and have a relationship with plant growth, development, and production. There are only a few reports on the effects of planting patterns of cassava on the microbial community structure in the rhizospheric soil. Here, we investigated the effects of different fertilization on the microbial community structure in the cassava rhizospheric soil. SC205 cultivar was used in this study as the experimental material. Compound fertilizer (CF) and reduced fertilizer (RF) were applied to the soil prior to planting. Soil samples were collected before harvest, and fungi were analyzed using IonS5TMXL sequencing platform. Results showed that CF and RF treatments significantly increased cassava yield. Amplicon sequencing result indicated that the fungi richness in rhizospheric soil of cassava was increased after CF was applied, and the diversity was decreased. However, the fungal diversity and richness were decreased in rhizospheric soil after RF was applied. The most dominant fungal phylum was Ascomycota, which increased after fertilization. In addition, the abundance of beneficial fungi such as Chaetomium increased after fertilization, while that of pathogenic fungi such as Fusarium solani was decreased. The composition of the fungal community in rhizospheric soil with CF and RF applied was similar, but the richness and diversity of fungi were different. Canonical correspondence analysis (CCA) indicates there was a positive correlation between soil nutrition and fungal community structure. Overall, our results indicate that fertilization alters the fungal community structure of cassava rhizospheric soil, such that the abundance of potentially beneficial fungi increased, while that of potentially pathogenic fungi decreased, thereby significantly promoting plant growth and yield of cassava. Thus, during actual production, attention should be paid to maintain the stability of cassava rhizospheric soil micro-ecology.


Agriculture ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1113
Author(s):  
Xiaolong Lin ◽  
Zongmu Yao ◽  
Xinguang Wang ◽  
Shangqi Xu ◽  
Chunjie Tian ◽  
...  

Rice is a staple food for the world’s population. However, the straw produced by rice cultivation is not used sufficiently. Returning rice straw to the field is an effective way to help reduce labor and protect the soil. This study focused on the effect of water-covered depth with the freeze–thaw cycle on rice straw decomposition and the soil fungal community structure in a field in Northeast China. The field and controlled experiments were designed, and the fungal ITS1 region was tested by high-throughput sequencing for analyzing the fungal communities in this study. The results showed that water coverage with the freeze–thaw cycle promoted the decomposition of rice straw and influenced the fungal community structure; by analyzing the network of the fungal communities, it was found that the potential keystone taxa were Penicillium, Talaromyces, Fusarium, and Aspergillus in straw decomposition; and the strains with high beta-glucosidase, carboxymethyl cellulase, laccase, lignin peroxidase, and manganese peroxidase could also be isolated in the treated experiment. Furthermore, plant pathogenic fungi were found to decrease in the water-covered treatment. We hope that our results can help in rice production and straw return in practice.


2020 ◽  
Author(s):  
Chuanbo Zhang ◽  
Chao-Hui Ren ◽  
Yan-Li Wang ◽  
Qi-Qi Wang ◽  
Yun-Sheng Wang ◽  
...  

Abstract Background The fungal communities inhabiting natural Ophiocordyceps sinensis play critical ecological roles in alpine meadow ecosystem, contribute to infect host insect, influence the occurrence of O. sinensis, and are repertoire of potential novel metabolites discovery. However, a comprehensive understanding of fungal communities of O. sinensis remain elusive. Therefore, the present study aimed to unravel fungal communities of natural O. sinensis using combination of high-throughput sequencing and culture-dependent approach. Results A total of 280,519 high-quality sequences, belonging to 5 fungal phyla, 15 classes, 41 orders, 79 families, 112 genera, and 352 putative operational taxonomic units (OTUs) were obtained from natural O. sinensis using high-throughput sequencing. Among of which, 43 genera were identified in external mycelial cortices (EMC), Ophiocordyceps, Sebacinia, Archaeorhizomyces were predominant genera with the abundance of 95.86%, 1.14%, 0.85%, respectively. Total 66 genera were identified from soil microhabitat, Inocybe, Archaeorhizomyces, Unclassified Thelephoraceae, Tomentella, Thelephora, Sebacina, Unclassified Ascomycota, Unclassified Fungi were predominant genera with an average abundance of 53.32%, 8.69%, 8.12%, 8.12%, 7.21%, 4.6%, 3.08% and 3.05%, respectively. The fungal communities in external mycelial cortices (EMC) were significantly distinct from the soil microhabitat (Soil). Meanwhile, seven culture media that benefit for the growth of O. sinensis were used to isolate culturable fungi at 16 °C, resulted in 77 fungal strains isolated for rDNA ITS sequence analysis, belonging to 33 genera, including Ophiocordyceps, Trichoderma, Cytospora, Truncatella, Dactylonectria, Isaria, Cephalosporium, Fusarium, Cosmospora, Paecilomyces, etc.. Among all culturable fungi, Mortierella and Trichoderma were predominant genera of total isolates. Conclusions The significantly distinction and overlap in fungal community structure between two approaches highlight that integration of approaches would generate more information than either of them. Our finding is the first investigation of fungal community structure of natural O. sinensis by two approachs, provide new insight into O. sinensis associated fungi, and support that microbiota of O. sinensis is an untapped source for novel bioactive metabolites discovery.


2020 ◽  
Vol 96 (7) ◽  
Author(s):  
Michael E Van Nuland ◽  
Dylan P Smith ◽  
Jennifer M Bhatnagar ◽  
Artur Stefanski ◽  
Sarah E Hobbie ◽  
...  

ABSTRACT The response to global change by soil microbes is set to affect important ecosystem processes. These impacts could be most immediate in transitional zones, such as the temperate-boreal forest ecotone, yet previous work in these forests has primarily focused on specific subsets of microbial taxa. Here, we examined how bacterial and fungal communities respond to simulated above- and below-ground warming under realistic field conditions in closed and open canopy treatments in Minnesota, USA. Our results show that warming and canopy disturbance shifted bacterial and fungal community structure as dominant bacterial and fungal groups differed in the direction and intensity of their responses. Ectomycorrhizal and saprotrophic fungal communities with greater connectivity (higher prevalence of strongly interconnected taxa based on pairwise co-occurrence relationships) were more resistant to compositional change. Warming effects on soil enzymes involved in the hydrolytic and oxidative liberation of carbon from plant cell walls and nutrients from organic matter were most strongly linked to fungal community responses, although community structure–function relationships differed between fungal guilds. Collectively, these findings indicate that warming and disturbance will influence the composition and function of microbial communities in the temperate-boreal ecotone, and fungal responses are particularly important to understand for predicting future ecosystem functioning.


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