Impacts of endophyte infection of ryegrass on rhizosphere metabolome and microbial community

2015 ◽  
Vol 66 (10) ◽  
pp. 1049 ◽  
Author(s):  
S. Wakelin ◽  
S. Harrison ◽  
C. Mander ◽  
B. Dignam ◽  
S. Rasmussen ◽  
...  

The use of grasses such as ryegrass and fescues infected with endophytic fungi of the Epichloë genus is widespread in New Zealand’s pastoral systems. Each endophyte–cultivar combination represents a distinctive genome–genome association, resulting in unique biological outcomes. The wider influence of these interactions on rhizosphere microbiology are not well characterised. This is important, because there may be opportunities or risks associated with selective disruption of the rhizosphere microbiota. We explored the interaction of two commercially used endophyte fungi, E. festucae var. lolii strains AR1 and AR37, within a genetically uniform breeding line of perennial ryegrass (Lolium perenne cv. Samson 11104) on the rhizosphere metabolome and the composition of the fungal, bacterial, and Pseudomonas communities. There were strong differences in the rhizosphere metabolomes between infested and non-infested ryegrass strains (P = 0.06). These were attributed to shifts in various n-alkane hydrocarbon compounds. The endophyte-associated alteration in rhizosphere metabolome was linked to changes in the total bacterial (P < 0.01) and fungal (P < 0.05) rhizosphere communities. Furthermore, there was varying levels of support for endophyte-specific (AR1 v. AR37) impacts on the bacterial and fungal communities. Pseudomonas bacterial communities were not influenced by endophyte infection of ryegrass (P = 0.834).

2021 ◽  
Vol 11 ◽  
Author(s):  
Yanru Chen ◽  
Kaimin Li ◽  
Ting Liu ◽  
Ruyi Li ◽  
Guiming Fu ◽  
...  

Special-flavor Baijiu is a unique Baijiu in Jiangxi Province, China, whose uniqueness mainly depends on the unique production process of special-flavor Baijiu Daqu. However, the microbial structure and physicochemical indices of different parts of the special-flavor Baijiu Daqu are still unknown. This greatly reduces the actual value of Daqu in the production of special-flavor Baijiu. Therefore, culture-dependent and Illumina MiSeq sequencing methods were used to analyze the microbial structure of special-flavor Baijiu Daqu. The results indicated that there was a complicated microbial diversity in Chinese special-flavor Baijiu Daqu. The predominant bacterial communities were Bacillales, Lactobacillales, and Rhodospirillales, while Saccharomycetales and Eurotiales were the predominant fungal communities. Significant differences in microbial community and distribution were shown between the surface and central parts of Daqu. Acetobacter and Pichia genera were the predominant microorganisms in the surface part of Daqu, whereas Aspergillus, Kroppenstedtia, Oceanobacillus, and Bacillus genera were the predominant microorganisms in the central part of Daqu. Meantime, the different microbial distributions between the surface and central parts of Daqu caused the significant differences in the physicochemical indices. These results can provide an important theoretical basis for improving the brewing process and the quality of special-flavor Baijiu.


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.


2020 ◽  
Author(s):  
Huaying Wang ◽  
Xiaoxue Fang ◽  
Hao Wu ◽  
Xinyu Cai ◽  
Hongxing Xiao

Abstract Background There is a growing awareness of the importance of root-associated bacteria and fungi to plant growth. At present, little is known about whether different ginseng cultivars affect the soil rhizosphere microbial community. Results Here, we examined the changes in the microorganismal diversity and composition of the rhizospheres of different ginseng cultivars. We found that fungal communities were more influenced by the cultivars than bacterial communities and revealed differences in the microbial community composition and diversity among the different ginseng cultivars. We found that fungal diversity was negatively correlated with bacterial diversity in CBGL, JYSH and SZSZ; however, TSBT had the lowest bacterial and fungal diversity. We also discovered certain rhizosphere microorganisms that may be associated with pathogenicity and the lifespan of ginseng cultivars, including Bacillus, Alternaria alternata and Cladosporium spp. Conclusions Our results showed that the microbial diversity and community structures under different ginseng cultivars are significantly different and are related to the host cultivar. This result is helpful in providing information that could be used for the breeding of Panax ginseng.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Polina Galitskaya ◽  
Liliya Biktasheva ◽  
Sergey Blagodatsky ◽  
Svetlana Selivanovskaya

AbstractPetroleum pollution of soils is a major environmental problem. Soil microorganisms can decompose a significant fraction of petroleum hydrocarbons in soil at low concentrations (1–5%). This characteristic can be used for soil remediation after oil pollution. Microbial community dynamics and functions are well studied in cases of moderate petroleum pollution, while cases with heavy soil pollution have received much less attention. We studied bacterial and fungal successions in three different soils with high petroleum contents (6 and 25%) in a laboratory experiment. The proportion of aliphatic and aromatic compounds decreased by 4–7% in samples with 6% pollution after 120 days of incubation but remained unchanged in samples with 25% hydrocarbons. The composition of the microbial community changed significantly in all cases. Oil pollution led to an increase in the relative abundance of bacteria such as Actinobacteria and the candidate TM7 phylum (Saccaribacteria) and to a decrease in that of Bacteroidetes. The gene abundance (number of OTUs) of oil-degrading bacteria (Rhodococcus sp., candidate class TM7-3 representative) became dominant in all soil samples, irrespective of the petroleum pollution level and soil type. The fungal communities in unpolluted soil samples differed more significantly than the bacterial communities. Nonmetric multidimensional scaling revealed that in the polluted soil, successions of fungal communities differed between soils, in contrast to bacterial communities. However, these successions showed similar trends: fungi capable of lignin and cellulose decomposition, e.g., from the genera Fusarium and Mortierella, were dominant during the incubation period.


Author(s):  
Ze Ren ◽  
Hongkai Gao

Bacterial and fungal communities in biofilms are important components in driving biogeochemical processes in stream ecosystems. Previous studies have well documented the patterns of bacterial alpha diversity in stream biofilms in glacier-fed streams, where, however, beta diversity of the microbial communities has received much less attention especially considering both bacterial and fungal communities. A focus on beta diversity can provide insights into the mechanisms driving community changes associated to large environmental fluctuations and disturbances, such as in glacier-fed streams. Moreover, modularity of co-occurrence networks can reveal more ecological and evolutionary properties of microbial communities beyond taxonomic groups. Here, integrating beta diversity and co-occurrence approach, we explored the network topology and modularity of the bacterial and fungal communities with consideration of environmental variation in glacier-fed streams in Central Asia. Combining results from hydrological modeling and normalized difference of vegetation index, this study highlighted that hydrological variables and vegetation status are major variables determining the environmental heterogeneity of glacier-fed streams. Bacterial communities formed a more complex and connected network, while the fungal communities formed a more clustered network. Moreover, the strong interrelations among the taxonomic dissimilarities of bacterial community and modules suggest they had common processes in driving diversity and taxonomic compositions across the heterogeneous environment. In contrast, fungal community and modules generally showed distinct driving processes to each other. Moreover, bacterial and fungal communities also had different driving processes. Furthermore, the variation of bacterial community and modules were strongly correlated with hydrological properties and vegetation status but not with nutrients, while fungal community and modules (except one module) were not associated with environmental variation. Our results suggest that bacterial and fungal communities had distinct mechanisms in structuring microbial networks, and environmental variation had strong influences on bacterial communities but not on fungal communities. The fungal communities have unique assembly mechanisms and physiological properties which might lead to their insensitive responses to environmental variations compared to bacterial communities. Overall, beyond alpha diversity in previous studies, these results add our knowledge that bacterial and fungal communities have contrasting assembly mechanisms and respond differently to environmental variation in glacier-fed streams.


2019 ◽  
Author(s):  
Ze Ren ◽  
Hongkai Gao

Bacterial and fungal communities in biofilms are important components in driving biogeochemical processes in stream ecosystems. Previous studies have well documented the patterns of bacterial alpha diversity in stream biofilms in glacier-fed streams, where, however, beta diversity of the microbial communities has received much less attention especially considering both bacterial and fungal communities. A focus on beta diversity can provide insights into the mechanisms driving community changes associated to large environmental fluctuations and disturbances, such as in glacier-fed streams. Moreover, modularity of co-occurrence networks can reveal more ecological and evolutionary properties of microbial communities beyond taxonomic groups. Here, integrating beta diversity and co-occurrence approach, we explored the network topology and modularity of the bacterial and fungal communities with consideration of environmental variation in glacier-fed streams in Central Asia. Combining results from hydrological modeling and normalized difference of vegetation index, this study highlighted that hydrological variables and vegetation status are major variables determining the environmental heterogeneity of glacier-fed streams. Bacterial communities formed a more complex and connected network, while the fungal communities formed a more clustered network. Moreover, the strong interrelations among the taxonomic dissimilarities of bacterial community and modules suggest they had common processes in driving diversity and taxonomic compositions across the heterogeneous environment. In contrast, fungal community and modules generally showed distinct driving processes to each other. Moreover, bacterial and fungal communities also had different driving processes. Furthermore, the variation of bacterial community and modules were strongly correlated with hydrological properties and vegetation status but not with nutrients, while fungal community and modules (except one module) were not associated with environmental variation. Our results suggest that bacterial and fungal communities had distinct mechanisms in structuring microbial networks, and environmental variation had strong influences on bacterial communities but not on fungal communities. The fungal communities have unique assembly mechanisms and physiological properties which might lead to their insensitive responses to environmental variations compared to bacterial communities. Overall, beyond alpha diversity in previous studies, these results add our knowledge that bacterial and fungal communities have contrasting assembly mechanisms and respond differently to environmental variation in glacier-fed streams.


2020 ◽  
Author(s):  
Yingdan Yuan ◽  
Mengting Zu ◽  
Lei Liu ◽  
Xiaomei Song

Abstract Background: Dendrobium is a precious herbal belongs to Orchid and widely used as health care traditional Chinese medicine in Asia. Although orchids are mycorrhizal plants, most researches still focus on endophytes, and there is still large unknown in rhizosphere microorganisms. In order to investigate the rhizosphere microbial community of different Dendrobium species during the maturity stage, we used high-throughput sequencing to analyze microbial community in rhizosphere soil during maturity stage of three kinds of Dendrobium species.Results: In our study, a total of 240,320 sequences and 11,179 OTUs were obtained from these three Dendrobium species. According to the analysis of OTU annotation results, different Dendrobium rhizosphere soil bacteria include 2 kingdoms, 63 phyla, 72 classes, 159 orders, 309 families, 850 genera and 663 species. Among all sequences, the dominant bacterial phyla (relative abundance > 1%) were Proteobacteria, Actinobacteria, Bacteroidetes, Acidobacteria, Firmicutes, Verrucomicrobia, Planctomycetes, Chloroflexi, Gemmatimonadetes. We analyzed the environmental factors of the growth of Dendrobium and found that the environmental factor that affects the rhizosphere soil microorganisms of Dendrobium is the soil factor. Among them, soil factors most closely related to the influence of Dendrobium rhizosphere soil microorganisms include total nitrogen, available phosphorus, ammonium nitrogen and pH value.Conclusions: We found that the rhizosphere bacterial communities of the three kinds of Dendrobium have significant differences, and the main species of rhizosphere microorganisms of Dendrobium are concentrated in the Proteobacteria, Actinobacteria, Bacteroidetes. Moreover, the smaller the level of bacterial, the greater the difference among Dendrobium species. Soil is the most important environmental factor affecting the bacterial communities in the rhizosphere soil of Dendrobium. These results fill the gap in the rhizosphere microbial community of Dendrobium and provide a theoretical basis for the subsequent mining of microbial functions and the study of biological fertilizers.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Anthony Horner ◽  
Samuel S. Browett ◽  
Rachael E. Antwis

AbstractModern agricultural practices have vastly increased crop production but negatively affected soil health. As such, there is a call to develop sustainable, ecologically-viable approaches to food production. Mixed-cropping of plant varieties can increase yields, although impacts on plant-associated microbial communities are unclear, despite their critical role in plant health and broader ecosystem function. We investigated how mixed-cropping between two field pea (Pisum sativum L.) varieties (Winfreda and Ambassador) influenced root-associated microbial communities and yield. The two varieties supported significantly different fungal and bacterial communities when grown as mono-crops. Mixed-cropping caused changes in microbial communities but with differences between varieties. Root bacterial communities of Winfreda remained stable in response to mixed-cropping, whereas those of Ambassador became more similar to Winfreda. Conversely, root fungal communities of Ambassador remained stable under mixed-cropping, and those of Winfreda shifted towards the composition of Ambassador. Microbial co-occurrence networks of both varieties were stronger and larger under mixed-cropping, which may improve stability and resilience in agricultural soils. Both varieties produced slightly higher yields under mixed-cropping, although overall Ambassador plants produced higher yields than Winfreda plants. Our results suggest that variety diversification may increase yield and promote microbial interactions.


2019 ◽  
Vol 366 (24) ◽  
Author(s):  
Elena Bovio ◽  
Estelle Sfecci ◽  
Anna Poli ◽  
Giorgio Gnavi ◽  
Valeria Prigione ◽  
...  

ABSTRACT Marine fungi are part of the huge and understudied biodiversity hosted in the sea. To broaden the knowledge on fungi inhabiting the Mediterranean Sea and their role in sponge holobiont, three sponges namely Aplysina cavernicola, Crambe crambe and Phorbas tenacior were collected in Villefranche sur Mer, (France) at about 25 m depth. The fungal communities associated with the sponges were isolated using different techniques to increase the numbers of fungi isolated. All fungi were identified to species level giving rise to 19, 13 and 3 species for P. tenacior, A. cavernicola and C. crambe, respectively. Of note, 35.7% and 50.0% of the species detected were either reported for the first time in the marine environment or in association with sponges. The mini-satellite analysis confirmed the uniqueness of the mycobiota of each sponge, leading to think that the sponge, with its metabolome, may shape the microbial community.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Rongrong Li ◽  
Di Jiang ◽  
Mingli Zheng ◽  
Pengjiao Tian ◽  
Menghu Zheng ◽  
...  

Abstract This study was conducted to examine the effects of Lactobacillus plantarum (LP) and sucrose (S) on clostridial community dynamics and correlation between clostridia and other bacteria in alfalfa silage during ensiling. Fresh alfalfa was directly ensiled without (CK) or with additives (LP, S, LP + S) for 7, 14, 28 and 56 days. Clostridial and bacterial communities were evaluated by next-generation sequencing. Severe clostridial fermentation occurred in CK, as evidenced by the high contents of butyric acid, ammonia nitrogen, and clostridia counts, whereas all additives, particularly LP + S, decreased silage pH and restrained clostridial fermentation. Clostridium perfringens and Clostridium butyricum might act as the main initiators of clostridial fermentation, with Clostridium tyrobutyricum functioning as the promoters of fermentation until the end of ensiling. Clostridium tyrobutyricum (33.5 to 98.0%) dominated the clostridial community in CK from 14 to 56 days, whereas it was below 17.7% in LP + S. Clostridium was negatively correlated with the genus Lactobacillus, but positively correlated with the genera Enterococcus, Lactococcus and Leuconostoc. Insufficient acidification promoted the vigorous growth of C. tyrobutyricum of silage in later stages, which was mainly responsible for the clostridial fermentation of alfalfa silage.


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