scholarly journals Silicon application and related changes in soil bacterial community dynamics reduced ginseng black spot incidence in Panax ginseng in a short-term study

2019 ◽  
Author(s):  
Meijia Li ◽  
Qiuxia Wang ◽  
Zhengbo Liu ◽  
Xiaoxi Pan ◽  
Yayu Zhang

Abstract Background This study analyzed the effect of silicon (Si) application on the occurrence of ginseng black spot caused by Alternaria panax . We explored the differences in soil physical and chemical factors and microbial community structure following Si application as well as the key factors that affected the occurrence of ginseng black spot in soil. Potted Panax ginseng plants were used to assess the effect of Si treatment on ginseng black spot. Soil physical and chemical properties were comprehensively analyzed. Bacterial communities were analyzed using Illumina HiSeq sequencing targeting the 16S rRNA gene. Results After inoculation with A. panax , the morbidity (and morbidity index) of ginseng with and without Si was 52% (46) and 83% (77), respectively. Soil physical and chemical analysis showed that under the ginseng black spot inoculation, bacterial communities were mainly affected by pH and available potassium, followed by ammonium nitrogen and available Si. NMDS and PLS-DA analyses and the heat maps of relative abundance revealed that Si application elevated the resistance of ginseng black spot as regulated by the abundance and diversity of bacterial flora in rhizosphere soils. Heatmap analysis at the genus level revealed that A. panax + Si inoculations significantly increased the soil community abundance of Sandaracinus , Polycyclovorans , Hirschia , Haliangium , Nitrospira , Saccharothrix , Aeromicrobium , Luteimonas , and Rubellimicrobium and led to a bacterial community structure with relative abundances that were significantly similar to that of untreated soil. Conclusions Short-term Si application also significantly regulated the structural impact on soil microorganisms caused by ginseng black spot. Our findings indicated that Si applications may possibly be used in the prevention and treatment of ginseng black spot.

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Meijia Li ◽  
Qiuxia Wang ◽  
Zhengbo Liu ◽  
Xiaoxi Pan ◽  
Yayu Zhang

Abstract Background This study analyzed the effect of silicon (Si) application on the occurrence of ginseng black spot caused by Alternaria panax. We explored the differences in soil physical and chemical factors and microbial community structure following Si application as well as the key factors that affected the occurrence of ginseng black spot in soil. Potted Panax ginseng plants were used to assess the effect of Si treatment on ginseng black spot. Soil physical and chemical properties were comprehensively analyzed. Bacterial communities were analyzed using Illumina HiSeq sequencing targeting the 16S rRNA gene. Results After inoculation with A. panax, the morbidity (and morbidity index) of ginseng with and without Si was 52% (46) and 83% (77), respectively. Soil physical and chemical analysis showed that under the ginseng black spot inoculation, bacterial communities were mainly affected by pH and available potassium, followed by ammonium nitrogen and available Si. NMDS and PLS-DA analyses and the heat maps of relative abundance revealed that Si application elevated the resistance of ginseng black spot as regulated by the abundance and diversity of bacterial flora in rhizosphere soils. Heatmap analysis at the genus level revealed that A. panax + Si inoculations significantly increased the soil community abundance of Sandaracinus, Polycyclovorans, Hirschia, Haliangium, Nitrospira, Saccharothrix, Aeromicrobium, Luteimonas, and Rubellimicrobium and led to a bacterial community structure with relative abundances that were significantly similar to that of untreated soil. Conclusions Short-term Si application also significantly regulated the structural impact on soil microorganisms caused by ginseng black spot. Our findings indicated that Si applications may possibly be used in the prevention and treatment of ginseng black spot.


2019 ◽  
Author(s):  
Meijia Li ◽  
Qiuxia Wang ◽  
Zhengbo Liu ◽  
Xiaoxi Pan ◽  
Yayu Zhang

Abstract Background This study analyzed the effect of silicon (Si) application on the occurrence of ginseng black spot caused by Alternaria panax . We explored the differences in soil physical and chemical factors and microbial community structure following Si application as well as the key factors that affected the occurrence of ginseng black spot in soil. Potted Panax ginseng plants were used to assess the effect of Si treatment on ginseng black spot. Soil physical and chemical properties were comprehensively analyzed. Bacterial communities were analyzed using Illumina HiSeq sequencing targeting the 16S rRNA gene. Results After inoculation with A. panax , the morbidity (and morbidity index) of ginseng with and without Si was 52% (46) and 83% (77), respectively. Soil physical and chemical analysis showed that under the ginseng black spot inoculation, bacterial communities were mainly affected by pH and available potassium, followed by ammonium nitrogen and available Si. NMDS and PLS-DA analyses and the heat maps of relative abundance revealed that Si application elevated the resistance of ginseng black spot as regulated by the abundance and diversity of bacterial flora in rhizosphere soils. Heatmap analysis at the genus level revealed that A. panax + Si inoculations significantly increased the soil community abundance of Sandaracinus , Polycyclovorans , Hirschia , Haliangium , Nitrospira , Saccharothrix , Aeromicrobium , Luteimonas , and Rubellimicrobium and led to a bacterial community structure with relative abundances that were significantly similar to that of untreated soil. Conclusions Short-term Si application also significantly regulated the structural impact on soil microorganisms caused by ginseng black spot. Our findings indicated that Si applications may possibly be used in the prevention and treatment of ginseng black spot.


2019 ◽  
Author(s):  
Meijia Li ◽  
Qiuxia Wang ◽  
Zhengbo Liu ◽  
Xiaoxi Pan ◽  
Yayu Zhang

Abstract Background This study analyzed the effect of silicon (Si) application on the occurrence of ginseng black spot caused by Alternaria panax . We explored the differences in soil physical and chemical factors and microbial community structure following Si application as well as the key factors that affected the occurrence of ginseng black spot in soil. Potted Panax ginseng plants were used to assess the effect of Si treatment on ginseng black spot. Soil physical and chemical properties were comprehensively analyzed. Bacterial communities were analyzed using Illumina HiSeq sequencing targeting the 16S rRNA gene. Results After inoculation with A. panax , the morbidity (and morbidity index) of ginseng with and without Si was 52% (46) and 83% (77), respectively. Soil physical and chemical analysis showed that under the ginseng black spot inoculation, bacterial communities were mainly affected by pH and available potassium, followed by ammonium nitrogen and available Si. NMDS and PLS-DA analyses and the heat maps of relative abundance revealed that Si application elevated the resistance of ginseng black spot as regulated by the abundance and diversity of bacterial flora in rhizosphere soils. Heatmap analysis at the genus level revealed that A. panax + Si inoculations significantly increased the soil community abundance of Sandaracinus , Polycyclovorans , Hirschia , Haliangium , Nitrospira , Saccharothrix , Aeromicrobium , Luteimonas , and Rubellimicrobium and led to a bacterial community structure with relative abundances that were significantly similar to that of untreated soil. Conclusions Short-term Si application also significantly regulated the structural impact on soil microorganisms caused by ginseng black spot. Our findings indicated that Si applications may possibly be used in the prevention and treatment of ginseng black spot.


2019 ◽  
Author(s):  
Meijia Li ◽  
Yayu Zhang

Abstract Background This study analyzed the effect of silicon (Si) application on the occurrence of ginseng black spot caused by Alternaria panax. We explored the differences in soil physical and chemical factors and microbial community structure following Si application as well as the key factors that affected the occurrence of ginseng black spot in soil. Potted Panax ginseng plants were used to assess the effect of Si treatment on ginseng black spot. Plants were grown under four kinds of treatment: (1) control (no inoculations), (2) inoculation with A. panax, (3) inoculation wit Si, and (4) inoculation with A. panax + Si, with 18 plants (3 pots) per treatment. Soil physical and chemical properties were comprehensively analyzed. Bacterial communities were analyzed using Illumina HiSeq sequencing targeting the 16S rRNA gene. Using micro-ecological regulation measures, we developed a theoretical basis for the prevention and control of ginseng black spot. Results After inoculation with A. panax, the morbidity (and morbidity index) of ginseng with and without Si was 52% (46) and 83% (77), respectively. Soil physical and chemical analysis showed that under the ginseng black spot inoculation, bacterial communities were mainly affected by pH and available potassium, followed by ammonium nitrogen and available Si. NMDS and PLS-DA analyses and the heat maps of relative abundance revealed that Si application elevated the resistance of ginseng black spot as regulated by the abundance and diversity of bacterial flora in rhizosphere soils. Heatmap analysis at the genus level revealed that A. panax + Si inoculations significantly increased the soil community abundance of Sandaracinus, Polycyclovorans, Hirschia, Haliangium, Nitrospira, Saccharothrix, Aeromicrobium, Luteimonas, and Rubellimicrobium and led to a bacterial community structure with relative abundances that were significantly similar to that of untreated soil. Conclusions Si alleviated the incidence of ginseng black spot by directly and indirectly affecting the structure and diversity of the soil microbial community. Short-term Si application also significantly regulated the structural impact on soil microorganisms caused by ginseng black spot. Our findings indicated that Si applications may possibly be used in the prevention and treatment of ginseng black spot.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Young Kyung Kim ◽  
Keunje Yoo ◽  
Min Sung Kim ◽  
Il Han ◽  
Minjoo Lee ◽  
...  

Abstract Bacterial communities in wastewater treatment plants (WWTPs) affect plant functionality through their role in the removal of pollutants from wastewater. Bacterial communities vary extensively based on plant operating conditions and influent characteristics. The capacity of WWTPs can also affect the bacterial community via variations in the organic or nutrient composition of the influent. Despite the importance considering capacity, the characteristics that control bacterial community assembly are largely unknown. In this study, we discovered that bacterial communities in WWTPs in Korea and Vietnam, which differ remarkably in capacity, exhibit unique structures and interactions that are governed mainly by the capacity of WWTPs. Bacterial communities were analysed using 16S rRNA gene sequencing and exhibited clear differences between the two regions, with these differences being most pronounced in activated sludge. We found that capacity contributed the most to bacterial interactions and community structure, whereas other factors had less impact. Co-occurrence network analysis showed that microorganisms from high-capacity WWTPs are more interrelated than those from low-capacity WWTPs, which corresponds to the tighter clustering of bacterial communities in Korea. These results will contribute to the understanding of bacterial community assembly in activated sludge processing.


2020 ◽  
Vol 27 (34) ◽  
pp. 42933-42947
Author(s):  
Xia Luo ◽  
Xinyi Xiang ◽  
Guoyi Huang ◽  
Xiaorui Song ◽  
Peijia Wang ◽  
...  

Abstract Extensive construction of dams by humans has caused alterations in flow regimes and concomitant alterations in river ecosystems. Even so, bacterioplankton diversity in large rivers influenced by cascade dams has been largely ignored. In this study, bacterial community diversity and profiles of seven cascade dams along the720 km of the Lancang River were studied using Illumina sequencing of the V3-V4 hypervariable region of the 16S rRNA gene. Spatiotemporal variations of bacterial communities in sediment and water of the Gongguoqiao hydroelectric dam and factors affecting these variations were also examined. Microbial diversity and richness in surface water increased slightly from upstream toward downstream along the river. A significant positive correlation between spatial distance and dissimilarities in bacterial community structure was confirmed (Mantel test, r = 0.4826, p = 0.001). At the Gongguoqiao hydroelectric dam, temporal differences in water overwhelmed spatial variability in bacterial communities. Temperature, precipitation, and nutrient levels were major drivers of seasonal microbial changes. Most functional groups associated with carbon cycling in sediment samples decreased from winter to summer. Our findings improve our understanding of associations, compositions, and predicted functional profiles of microbial communities in a large riverine ecosystem influenced by multiple cascade dams.


2002 ◽  
Vol 68 (12) ◽  
pp. 6094-6105 ◽  
Author(s):  
Regin Rønn ◽  
Allison E. McCaig ◽  
Bryan S. Griffiths ◽  
James I. Prosser

ABSTRACT The influence of grazing by a mixed assemblage of soil protozoa (seven flagellates and one amoeba) on bacterial community structure was studied in soil microcosms amended with a particulate resource (sterile wheat roots) or a soluble resource (a solution of various organic compounds). Sterilized soil was reinoculated with mixed soil bacteria (obtained by filtering and dilution) or with bacteria and protozoa. Denaturing gradient gel electrophoresis (DGGE) of PCR amplifications of 16S rRNA gene fragments, as well as community level physiological profiling (Biolog plates), suggested that the mixed protozoan community had significant effects on the bacterial community structure. Excising and sequencing of bands from the DGGE gels indicated that high-G+C gram-positive bacteria closely related to Arthrobacter spp. were favored by grazing, whereas the excised bands that decreased in intensity were related to gram-negative bacteria. The percentages of intensity found in bands related to high G+C gram positives increased from 4.5 and 12.6% in the ungrazed microcosms amended with roots and nutrient solution, respectively, to 19.3 and 32.9% in the grazed microcosms. Protozoa reduced the average bacterial cell size in microcosms amended with nutrient solution but not in the treatment amended with roots. Hence, size-selective feeding may explain some but not all of the changes in bacterial community structure. Five different protozoan isolates (Acanthamoeba sp., two species of Cercomonas, Thaumatomonas sp., and Spumella sp.) had different effects on the bacterial communities. This suggests that the composition of protozoan communities is important for the effect of protozoan grazing on bacterial communities.


Soil Research ◽  
2020 ◽  
Vol 58 (8) ◽  
pp. 779
Author(s):  
Jian Zhang ◽  
Yinghe Xie ◽  
Ying Wei ◽  
Huisheng Meng ◽  
Yanzhuan Cao ◽  
...  

The recovery of the belowground microbial community structure and diversity that occurs in long-term coal mining reclamation is critical to reclamation success. However, long-term coal mining reclamation can take ~10–30 years. Therefore, finding an effective method for promoting coal mine soil restoration in the short-term is necessary to minimise reclamation time. This study investigated the response of soil bacterial communities to fertilisation along a chronosequence of short-term reclamation. Fertilised and unfertilised soils with three short-term reclamation stages were examined to characterise soil properties, as well as bacterial structure and diversity. Fertilisation promoted available nitrogen, phosphate, potassium, and soil organic matter, as well as benefits in bacterial community diversity across the three stages, with the most beneficial effects at 7 years. 16S rRNA sequencing data showed that the predominant phyla across all soils were Proteobacteria, Actinobacteria, Acidobacteria, Bacteroidetes, Chloroflexi, and Gemmatimonadetes. Abundance of each phylum was altered by reclamation time and fertilisation. Clustering and functional analysis indicated that the bacterial community structure in soils with a longer reclamation time was more similar to that in natural soils, suggesting that longer reclamation resulted in increased soil activity and bacterial community diversity, which is likely also true for fertilisation. Our results demonstrate that reclamation duration is the main driving force to recover soil properties and bacterial communities, and fertilisation could enhance the beneficial effects with longer reclamation duration. Therefore, short-term reclamation, combined with fertiliser, is a potential strategy to improve soil conditions in coal mine areas and shorten the recovery time of reclaimed soils.


2020 ◽  
Vol 96 (8) ◽  
Author(s):  
Xia Luo ◽  
Xinyi Xiang ◽  
Yuanhao Yang ◽  
Guoyi Huang ◽  
Kaidao Fu ◽  
...  

ABSTRACT Terrestrial microbial communities may take advantage of running waters and runoff to enter rivers and mix with aquatic microorganisms. However, the environmental factors governing the interchange of the microbial community within a watercourse and its surrounding environment and the composition of the resulting community are often underestimated. The present study investigated the effect of flow rate on the mixing of water, soil, sediment and biofilm at four sites along the Lancang River and one branch of the river in winter and summer and, in turn, the resultant changes in the microbial community within each habitat. 16S rRNA gene-based Illumina high-throughput sequencing illustrated that bacterial communities were apparently distinct among biofilm, water, soil and sediment. Biofilms had the lowest richness, Shannon diversity and evenness indices compared with other habitats, and those three indices in all habitats increased significantly from winter to summer. SourceTracker analysis showed a significant coalescence between the bacterial communities of sediment, water and biofilm samples at lower flow rates. Additionally, the proportion of Betaproteobacteria in sediment and biofilms increased with a decrease in flow rate, suggesting the flow rate had a strong impact on microbial community composition and exchange among aquatic habitats. These results were further confirmed by a Mantel test and linear regression analysis. Microbial communities in all samples exhibited a significant but very weak distance–decay relationship (r = 0.093, P = 0.024). Turbidity played a much more important role on water bacterial community structure in summer (i.e. rainy season) (BIOENV, r = 0.92). Together, these results suggest that dispersal is an important factor affecting bacterial community structure in this system.


2021 ◽  
Author(s):  
Rajsekhar Adhikary ◽  
Sukhendu Mandal ◽  
Vivekananda Mandal

Abstract Assessment of bacterial community dynamics helps to estimate the endophytic community structure and ecological behaviour imposed by them. Such community composition is essential to understand the molecular interplay that lies between them and the host plants. The present study aims to explore the endophytic bacterial communities and their dynamics in the pre-flowering and post-flowering seasons in the horticulturally important Mango (Mangifera indica L.) and its hemiparasites Loranthus sp., and Macrosolen sp. through a metagenomic approach using the sequence of V3 region of 16S rRNA gene. Bacillus was found to be the most abundant genera, followed by Acinetobacter, and Corynebacterium, which belong to the phyla Firmicutes, Proteobacteria, and Actinobacteria. It has been found that during the post-flowering season, twigs and leaves of mango have lower endophytic bacterial loads. Furthermore, the alpha-diversity indices of the representative genera were highest in Loranthus sp. during the post-flowering seasons of mango. The ecological, taxonomic, and complex correlation studies unravelled that the hemiparasites act as the potent reservoirs of endophytic community throughout the year, and during favourable conditions, these bacterial communities disseminate to the mango plant.


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