scholarly journals Fungi-Bacteria Associations in Wilt Diseased Rhizosphere and Endosphere by Interdomain Ecological Network Analysis

2021 ◽  
Vol 12 ◽  
Author(s):  
Lin Tan ◽  
Wei-ai Zeng ◽  
Yansong Xiao ◽  
Pengfei Li ◽  
Songsong Gu ◽  
...  

In the plant rhizosphere and endosphere, some fungal and bacterial species regularly co-exist, however, our knowledge about their co-existence patterns is quite limited, especially during invasion by bacterial wilt pathogens. In this study, the fungal communities from soil to endophytic compartments were surveyed during an outbreak of tobacco wilt disease caused by Ralstonia solanacearum. It was found that the stem endophytic fungal community was significantly altered by pathogen invasion in terms of community diversity, structure, and composition. The associations among fungal species in the rhizosphere and endosphere infected by R. solanacearum showed more complex network structures than those of healthy plants. By integrating the bacterial dataset, associations between fungi and bacteria were inferred by Inter-Domain Ecological Network (IDEN) approach. It also revealed that infected samples, including both the rhizosphere and endosphere, had more complex interdomain networks than the corresponding healthy samples. Additionally, the bacterial wilt pathogenic Ralstonia members were identified as the keystone genus within the IDENs of both root and stem endophytic compartments. Ralstonia members was negatively correlated with the fungal genera Phoma, Gibberella, and Alternaria in infected roots, as well as Phoma, Gibberella, and Diaporthe in infected stems. This suggested that those endophytic fungi may play an important role in resisting the invasion of R. solanacearum.

Author(s):  
Xiaoxiao Li ◽  
Qi Zhang ◽  
Jing Ma ◽  
Yongjun Yang ◽  
Yifei Wang ◽  
...  

Irrigation has been applied on a large scale for the improvement of grain yield per hectare and production stability. However, the dryland-to-paddy conversion affects the ecological environment of areas of long-term dry farming, especially soil microorganisms. Little attention has been paid to the changes in microbial communities and the interactions between their populations in this process. Therefore, in this paper, the compositions and diversity of soil bacterial and fungal communities were explored through a combination of high-throughput sequencing technology and molecular ecological network methods using bacterial 16S rRNA and fungal ITS. The results showed that: (1) both the abundance and diversity of soil bacteria and fungi decreased in a short time, and the abundance of Actinobacteria, Firmicutes and Olpidiomycota varied greatly. (2) Compared to dry land, the modular structure of interaction networks and interspecific relationships of bacterial and fungal communities in paddy soil were simpler, and the network became more unstable. A cooperative relationship dominated in the molecular ecological network of bacteria, while a competitive relationship was dominant in the network of fungi. Actinobacteria and Firmicutes were the dominant bacterial species in dry land and paddy field, respectively. Ascomycota was dominant in the fungal communities of both dry land and paddy field. (3) The change in soil environmental factors, such as pH, electrical conductivity (EC), organic matter (OM) and available potassium (AK), directly affected the soil microbial community structure, showing a significant correlation (p < 0.05). These environmental factors also influenced the dominant microbial species. Microorganisms are the most important link in the carbon and nitrogen cycles of soil, and a large-scale dryland-to-paddy conversion may reduce the ecological stability of regional soil.


2009 ◽  
Vol 55 (4) ◽  
pp. 375-387 ◽  
Author(s):  
Amy Novinscak ◽  
Nadine J. DeCoste ◽  
Céline Surette ◽  
Martin Filion

Composting is a microbial process that converts organic waste into a nutrient-rich end product used in horticultural and agricultural applications. The diversity and long-term succession of microorganisms found in composted biosolids has been less characterized than other composts. In this study, bacterial and fungal communities found in composted biosolids aging from 1 to 24 months were studied using denaturing gradient gel electrophoresis (DGGE) and sequencing. The results revealed high levels of diversity, where 53 bacterial species belonging to 10 phyla and 21 fungal species belonging to 4 phyla were identified. Significant differences were observed when comparing the bacterial DGGE patterns of young compost samples, whereas no differences were observed in samples over 8 months. For fungal patterns, no significant differences were observed during the first 4 months of composting, but the diversity then significantly shifted until 24 months. The results indicate that patterns of bacterial species vary during the first few months of composting, whereas fungal patterns generally vary throughout the whole process, except during early stages. The description of the main microbial groups found in composted biosolids could find various applications, including the discovery of biotechnologically relevant microorganisms and the development of novel markers allowing quantitative monitoring of key microorganisms.


2020 ◽  
Vol 8 (6) ◽  
pp. 806
Author(s):  
Lv Su ◽  
Lifan Zhang ◽  
Duoqian Nie ◽  
Eiko E. Kuramae ◽  
Biao Shen ◽  
...  

Soil-borne pathogen invasions can significantly change the microbial communities of the host rhizosphere. However, whether bacterial Ralstonia solanacearum pathogen invasion influences the abundance of fungal pathogens remains unclear. In this study, we combined high-throughput sequencing, qPCR, liquid chromatography and soil culture experiments to analyze the rhizosphere fungal composition, co-occurrence of fungal communities, copy numbers of functional genes, contents of phenolic acids and their associations in healthy and bacterial wilt-diseased tomato plants. We found that R. solanacearum invasion increased the abundance of the soil-borne pathogen Fusarium solani. The concentrations of three phenolic acids in the rhizosphere soil of bacterial wilt-diseased tomato plants were significantly higher than those in the rhizosphere soil of healthy tomato plants. In addition, the increased concentrations of phenolic acids significantly stimulated F. solani growth in the soil. Furthermore, a simple fungal network with fewer links, nodes and hubs (highly connected nodes) was found in the diseased tomato plant rhizosphere. These results indicate that once the symptom of bacterial wilt disease is observed in tomato, the roots of the wilt-diseased tomato plants need to be removed in a timely manner to prevent the enrichment of other fungal soil-borne pathogens. These findings provide some ecological clues for the mixed co-occurrence of bacterial wilt disease and other fungal soil-borne diseases.


2020 ◽  
Author(s):  
Ying Zhang ◽  
Anna Hu ◽  
Jianuan Zhou ◽  
Wenfei Zhang ◽  
Peng Li

Abstract BackgroundRalstonia solanacearum is one of the most notorious soil-born phytopathogen that causes a severe wilt disease with deadly effects on many economically important crops. The microbial community structure and interactions are commonly changed between bacterial wilt susceptible soil and healthy soil. Here, the bacterial community structure, correlation analysis with soil chemical properties, interaction network of healthy soil (HS, nearly no disease happened at recent three years) and diseased soil (DS, suffered heavy bacterial wilt disease) were analyzed.ResultsCompared to DS, a higher bacterial community diversity index was found in HS, and the relative abundance of main genera Bacillus, Gaiellales, Roseiflexus, Gemmatimonadaceae, Nocardioides and Anaerolineacear reached significant level. Redundancy analysis on genus level indicated that rapid available phosphate played key role on bacterial community distribution difference, and showed negative correlation with the other four chemical properties. Interaction network analysis further demonstrated that the higher genus community diversity and more extensive interactions were existed in HS network and formed stable network, and the genera Mycobacterium, Cyanobacteria and Rhodobiaceae should be the key components that sustain the network stably. Seven clusters of orthologous groups reached significant level difference between HS and DS. Moreover, 55 bacterial strains with distinct antagonistic activities to R. solancearum were isolated and identified. ConclusionsIn summary, our findings indicate that the bacterial diversity and interaction network changed between the HS and DS samples, which are also provide a good research basis for future biological control to the bacterial wilt.


2020 ◽  
Author(s):  
Ying Zhang ◽  
Anna Hu ◽  
Jianuan Zhou ◽  
Wenfei Zhang ◽  
Peng Li

Abstract Background: Ralstonia solanacearum is one of the most notorious soil-borne phytopathogens. It causes a severe wilt disease with deadly effects on many economically important crops. The microbita of disease-suppressive soils are thought that they can contribute to the disease resistance of crop plants, thus, to conduct the microbial community and their interaction characteristics between suppressive soil (SS) and conducive soil (CS) will help to understand resistance mechanism. Here, the bacterial community structure, correlation analysis with soil chemical properties, interaction network of SS (nearly no disease in three years), and CS (suffered heavy bacterial wilt disease) were analyzed. Results: Compared with CS, a higher bacterial community diversity index was found in SS , and the relative abundance of main genera Bacillus , Gaiellales , Roseiflexus , Gemmatimonadaceae , Nocardioides , and Anaerolineacear reached significant levels. Redundancy analysis at the genus level indicated that the available phosphate played a key role in the bacterial community distribution, and its role was negatively correlated with soil pH, organic matter content, alkali-hydrolyzable nitrogen, and available potassium contents. Interaction network analysis further demonstrated that greater diversity at the genus level existed in the SS network and formed a stable network. Additionally, the species of Mycobacterium , Cyanobacteria , and Rhodobiaceae are the key components that sustain the network stability. Seven clusters of orthologous groups exhibited significant differences between SS and CS. Moreover, 55 bacterial strains with distinct antagonistic activities to R. solancearum were isolated and identified. Conclusions: Our findings indicate that the bacterial diversity and interaction network differed between the CS and SS samples, providing a good foundation in the study of bacterial wilt.


2020 ◽  
Vol 8 (5) ◽  
pp. 632 ◽  
Author(s):  
Fei Xie ◽  
Anzhou Ma ◽  
Hanchang Zhou ◽  
Yu Liang ◽  
Jun Yin ◽  
...  

The biodiversity of fungi, which are extremely important in maintaining the ecosystem balance in alpine lakeside wetlands, has not been fully studied. In this study, we investigated the fungal communities of three lakeside wetlands from different altitudes in the Qinghai–Tibet Plateau and its edge. The results showed that the fungi of the alpine lakeside wetland had higher species diversity. Functional annotation of fungi by FUNGild software showed that saprophytic fungi were the most abundant type in all three wetlands. Further analysis of the microbial phylogenetic molecular ecological network (pMEN) showed that saprophytic fungi are important species in the three wetland fungal networks, while symbiotic fungi and pathotrophic fungi have different roles in the fungal networks in different wetlands. Community diversity was high in all three lakeside wetlands, but there were significant differences in the composition, function and network structure of the fungal communities. Contemporary environmental conditions (soil properties) and historical contingencies (geographic sampling location) jointly determine fungi community diversity in this study. These results expand our knowledge of fungal biodiversity in the alpine lakeside wetlands.


Insects ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 327
Author(s):  
Guiqing Liu ◽  
Xuehong Zheng ◽  
Hailin Long ◽  
Zhongchen Rao ◽  
Li Cao ◽  
...  

By employing a culture-dependent and -independent 16S rRNA and ITS gene high-throughput sequencing analyses, comprehensive information was obtained on the gut bacterial and fungal communities in the ghost moth larvae of three different geographic locations from high-altitude on Tibet plateau and from low-altitude laboratory. Twenty-six culturable bacterial species belonging to 21 genera and 14 fungal species belonging to 12 genera were identified from six populations by culture-dependent method. Carnobacterium maltaromaticum was the most abundant bacterial species from both the wild and laboratory-reared larvae. The most abundant OTUs in the wild ghost moth populations were Carnobacteriaceae, Enterobacteriaceae for bacteria, and Ascomycota and Basidiomycota for fungi. Larval microbial communities of the wild ghost moth from different geographic locations were not significantly different from each other but significant difference in larval microbial community was detected between the wild and laboratory-reared ghost moth. The larval gut of the wild ghost moth was dominated by the culturable Carnobacterium. However, that of the laboratory-reared ghost moth exhibited significantly abundant Wolbachia, Rhizobium, Serratia, Pseudomonas, and Flavobacterium. Furthermore, the larval gut of the wild ghost moth had a significantly higher abundance of Ophiocordyceps but lower abundance of Candida and Aspergillus than that of the laboratory-reared ghost moth.


2019 ◽  
Vol 65 (7) ◽  
pp. 538-549
Author(s):  
Xuefang Zheng ◽  
Bo Liu ◽  
Yujing Zhu ◽  
Jieping Wang ◽  
Haifeng Zhang ◽  
...  

Tomato bacterial wilt caused by Ralstonia solanacearum is a devastating plant disease. The aims of this study were to investigate the relationship among soil nutrients, rhizobacterial community, and abundance of R. solanacearum, and to gather useful information for controlling the disease. Fifteen tomato rhizosphere soils were collected from three regions, encompassing five disease grades. Then, soil physicochemical properties and rhizobacterial communities were investigated. The content of soil organic carbon (SOC), total phosphorus (TP), total potassium (TK), and exchangeable calcium was significantly higher in the healthy plant rhizosphere soils than in diseased plant rhizosphere soils (P < 0.05). The healthy soils had a relatively higher abundance of Proteobacteria and a lower abundance of Acidobacteria than the diseased soils from the same region. Redundancy analysis demonstrated that R. solanacearum abundance was positively correlated with total nitrogen content and negatively correlated with soil pH, SOC, TP, TK, and exchangeable calcium. Ralstonia solanacearum abundance correlated positively with Chloroflexi, Acidobacteria, and Planctomycetes abundance but negatively with Nitrospirae, Bacteroidetes, and Proteobacteria abundance. These results suggested that improving soil pH, applying the amount of P and K fertilizers, and controlling the dosage of N fertilizer might be an effective approach in controlling bacterial wilt disease.


2015 ◽  
Vol 81 (7) ◽  
pp. 2445-2454 ◽  
Author(s):  
Qichao Tu ◽  
Mengting Yuan ◽  
Zhili He ◽  
Ye Deng ◽  
Kai Xue ◽  
...  

ABSTRACTFungal communities play a major role as decomposers in the Earth's ecosystems. Their community-level responses to elevated CO2(eCO2), one of the major global change factors impacting ecosystems, are not well understood. Using 28S rRNA gene amplicon sequencing and co-occurrence ecological network approaches, we analyzed the response of soil fungal communities in the BioCON (biodiversity, CO2, and N deposition) experimental site in Minnesota, USA, in which a grassland ecosystem has been exposed to eCO2for 12 years. Long-term eCO2did not significantly change the overall fungal community structure and species richness, but significantly increased community evenness and diversity. The relative abundances of 119 operational taxonomic units (OTU; ∼27% of the total captured sequences) were changed significantly. Significantly changed OTU under eCO2were associated with decreased overall relative abundance of Ascomycota, but increased relative abundance of Basidiomycota. Co-occurrence ecological network analysis indicated that eCO2increased fungal community network complexity, as evidenced by higher intermodular and intramodular connectivity and shorter geodesic distance. In contrast, decreased connections for dominant fungal species were observed in the eCO2network. Community reassembly of unrelated fungal species into highly connected dense modules was observed. Such changes in the co-occurrence network topology were significantly associated with altered soil and plant properties under eCO2, especially with increased plant biomass and NH4+availability. This study provided novel insights into how eCO2shapes soil fungal communities in grassland ecosystems.


2020 ◽  
Author(s):  
Ying Zhang ◽  
Anna Hu ◽  
Jianuan Zhou ◽  
Wenfei Zhang ◽  
Peng Li

Abstract Background: Ralstonia solanacearum is one of the most notorious soil-borne phytopathogens. It causes a severe wilt disease with deadly effects on many economically important crops. The microbita of disease-suppressive soils are thought that they can contribute to the disease resistance of crop plants, thus, to conduct the microbial community and their interaction characteristics between suppressive soil (SS) and conducive soil (CS) will help to understand resistance mechanism. Here, the bacterial community structure, correlation analysis with soil chemical properties, interaction network of SS (nearly no disease in three years), and CS (suffered heavy bacterial wilt disease) were analyzed. Results: Compared with CS, a higher bacterial community diversity index was found in SS , and the relative abundance of main genera Bacillus , Gaiellales , Roseiflexus , Gemmatimonadaceae , Nocardioides , and Anaerolineacear reached significant levels. Redundancy analysis at the genus level indicated that the available phosphate played a key role in the bacterial community distribution, and its role was negatively correlated with soil pH, organic matter content, alkali-hydrolyzable nitrogen, and available potassium contents. Interaction network analysis further demonstrated that greater diversity at the genus level existed in the SS network and formed a stable network. Additionally, the species of Mycobacterium , Cyanobacteria , and Rhodobiaceae are the key components that sustain the network stability. Seven clusters of orthologous groups exhibited significant differences between SS and CS. Moreover, 55 bacterial strains with distinct antagonistic activities to R. solancearum were isolated and identified. Conclusions: Our findings indicate that the bacterial diversity and interaction network differed between the CS and SS samples, providing a good foundation in the study of bacterial wilt.


Sign in / Sign up

Export Citation Format

Share Document