scholarly journals Seasonal Variation Imparts The Endophytic Bacterial Community Dynamics in Mango Plants and Its Hemiparasites

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.

Author(s):  
Jenifer B Walke ◽  
Matthew H Becker ◽  
Arianna Krinos ◽  
Elizabeth A B Chang ◽  
Celina Santiago ◽  
...  

Abstract Amphibians host diverse skin bacteria that have a role in pathogen defense, but these skin communities could change over time and impact this function. Here, we monitored individual Eastern red-spotted newts (Notophthalmus viridescens; N = 17) for two years in a field pond enclosure and assessed the effects of season and disturbance on skin bacterial community dynamics. We created disturbances by adding additional pond substrate to the enclosure at two timepoints. We planned to sample the skin bacterial community and metabolite profiles of each newt every six weeks; we ultimately sampled eight individuals at least six times. We used 16S rRNA gene amplicon sequencing to characterize the bacterial communities and HPLC-MS for metabolite profiling. We found that disturbance had a dramatic effect on skin bacterial communities and metabolite profiles, while season had an effect only using select metrics. There were seven core bacterial taxa (97% OTUs) that were found on all newts in all seasons, pre- and post-disturbance. Lastly, there was a correlation between bacterial and metabolite profiles post-disturbance, which was not observed pre-disturbance. This longitudinal study suggests that environmental disturbances can have lasting effects on skin bacterial communities that overwhelm seasonal changes, although the core bacteria remain relatively consistent over time.


2017 ◽  
Author(s):  
Alexandra M. Linz ◽  
Benjamin C. Crary ◽  
Ashley Shade ◽  
Sarah Owens ◽  
Jack A. Gilbert ◽  
...  

AbstractBacteria play a key role in freshwater biogeochemical cycling, but long-term trends in freshwater bacterial community composition and dynamics are not yet well characterized. We used a multi-year time series of 16S rRNA gene amplicon sequencing data from eight bog lakes to census the freshwater bacterial community and observe annual and seasonal trends in abundance. Multiple sites and sampling events were necessary to begin to fully describe the bacterial communities. Each lake and layer contained a distinct bacterial community, with distinct levels of richness and indicator taxa that likely reflected the environmental conditions of each site. The community present in each year and site was also unique. Despite high interannual variability in community composition, we detected a core community of ubiquitous freshwater taxa. Although trends in abundance did not repeat annually, each freshwater lineage within the communities had a consistent lifestyle, defined by persistence, abundance, and variability. The results of our analysis emphasize the importance of long-term observations, as analyzing only a single year of data would not have allowed us to describe the dynamics and composition of these freshwater bacterial communities to the extent presented here.ImportanceLakes are excellent systems for investigating bacterial community dynamics because they have clear boundaries and strong environmental gradients. The results of our research demonstrate that bacterial community dynamics operate on multi-year timescales, a finding which likely applies to other ecosystems, with implications for study design and interpretation. Understanding the drivers and controls of bacterial communities on long time scales would improve both our knowledge of fundamental properties of bacterial communities, and our ability to predict community states. In this specific ecosystem, bog lakes play a disproportionately large role in global carbon cycling, and the information presented here may ultimately help refine carbon budgets for these lakes. Finally, all data and code in this study are publicly available. We hope that this will serve as a resource to anyone seeking to answer their own microbial ecology questions using a multi-year time series.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Brooke A. Clemmons ◽  
Madison T. Henniger ◽  
Phillip R. Myer

Abstract Objectives Extensive efforts have been made to characterize the rumen microbiome under various conditions. However, few studies have addressed the long-term impacts of ruminal microbiome dysbiosis and the extent of host control over microbiome stability. These data can also inform host-microbial symbioses. The objective was to develop preliminary data to measure the changes that occur in the rumen bacterial communities following a rumen content exchange to understand the effects major perturbations may impart upon the rumen microbiome, which may be host-driven. Data description We report here an initial rumen content exchange between two SimAngus (Simmental/Angus) non-pregnant, non-lactating cows of ~ 6 years of age weighing 603.4 ± 37.5 kg. To measure bacterial community succession and acclimation following the exchange, rumen content was collected via rumen cannula at the beginning of the study immediately prior to and following the rumen content exchange, and weekly for 12 weeks. The V4 hypervariable region of the 16S rRNA gene was targeted for DNA sequencing and bacterial analysis. Over 12 weeks, numerous genera and diversity varied, before partial return to pre-exchange metrics. These preliminary data help support potential host control for the rumen microbiome, aiding in efforts to define bovine host-microbe relationships.


2018 ◽  
Author(s):  
Tyler J. Carrier ◽  
Adam M. Reitzel

ABSTRACTDevelopment of some animals is influenced by and, in some cases, dependent on the associated microbiota. The timing of when associated bacterial communities are established during the development of marine invertebrates and their subsequent dynamics across stages are known for only a few species. Here, we compare the bacterial communities of three confamilial echinoids from egg to juvenile using sequence-based approaches. Bacterial communities are established on unfertilized eggs and change gradually during embryonic and larval development. Despite the differences amongst these pre-metamorphic stages, approximately thirty-percent of OTUs identified in association with unfertilized egg were present in the juveniles. During embryonic development, host-associated communities diverged from the environmental microbiota but later converged following the onset of larval feeding. Taken together, the data presented here support the hypothesis that bacterial communities are established prior to fertilization and community composition shifts gradually thereafter, all while remaining distinct from the environment. Future work will need to determine the relative influence of the host and bacteria-bacteria interactions in shaping the associated bacterial community to determine the potential functional importance of bacteria during the development of larval sea urchins and benthic marine invertebrates more broadly.


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.


2021 ◽  
Author(s):  
Md Majharul Islam ◽  
Rajarshi Bhattacharya ◽  
Biraj Sarkar ◽  
Pulak Kumar Maiti ◽  
Shouvik Mahanty ◽  
...  

Abstract The rhizospheric microbiome is capable of changing the physio-chemical properties of its own micro-environment and found to be indispensable in overall health of the host-plant. The interplay between the rhizospheric environment and the microbiota residing therein tune the physiology of the associated plant. In this study, we have determined how the soil properties and the host-plant remains as an important parameter for microbial community-dynamics in the rhizosphere of rice and peanut. In addition to check the physio-chemical parameters of the rhizospheric soil, we have also prepared the metagenomic DNA from each rhizospheric soil followed by high-throughput sequencing and sequence-analysis to predict the OTUs that represents the community structure. The alpha-diversity of the bacterial community in the RRN sample was highest, while the lowest was in PRS sample. Actinobacteria is the most predominant phylum in PRN, PRS and RRN whereas Acidobacteria in RRS. We found a clear shift in bacterial community over the rice and peanut rhizosphere and also over these host-rhizospheres from normal and high saline region. The rhizospheric bacterial community composition found to be affected by the close-by environmental factors. Thus, the rhizospheric bacterial community-structure is related to both the adjoining soil characters and the type of the hosts.


2000 ◽  
Vol 66 (2) ◽  
pp. 578-587 ◽  
Author(s):  
Lasse Riemann ◽  
Grieg F. Steward ◽  
Farooq Azam

ABSTRACT Bacterial community composition, enzymatic activities, and carbon dynamics were examined during diatom blooms in four 200-liter laboratory seawater mesocosms. The objective was to determine whether the dramatic shifts in growth rates and ectoenzyme activities, which are commonly observed during the course of phytoplankton blooms and their subsequent demise, could result from shifts in bacterial community composition. Nutrient enrichment of metazoan-free seawater resulted in diatom blooms dominated by a Thalassiosira sp., which peaked 9 days after enrichment (≈24 μg of chlorophylla liter−1). At this time bacterial abundance abruptly decreased from 2.8 × 106 to 0.75 × 106 ml−1, and an analysis of bacterial community composition, by denaturing gradient gel electrophoresis (DGGE) of PCR-amplified 16S rRNA gene fragments, revealed the disappearance of three dominant phylotypes. Increased viral and flagellate abundances suggested that both lysis and grazing could have played a role in the observed phylotype-specific mortality. Subsequently, new phylotypes appeared and bacterial production, abundance, and enzyme activities shifted from being predominantly associated with the <1.0-μm size fraction towards the >1.0-μm size fraction, indicating a pronounced microbial colonization of particles. Sequencing of DGGE bands suggested that the observed rapid and extensive colonization of particulate matter was mainly by specialized α-Proteobacteria- andCytophagales-related phylotypes. These particle-associated bacteria had high growth rates as well as high cell-specific aminopeptidase, β-glucosidase, and lipase activities. Rate measurements as well as bacterial population dynamics were almost identical among the mesocosms indicating that the observed bacterial community dynamics were systematic and repeatable responses to the manipulated conditions.


2019 ◽  
Vol 7 (12) ◽  
pp. 632 ◽  
Author(s):  
Carmen Rizzo ◽  
Roberta Malavenda ◽  
Berna Gerçe ◽  
Maria Papale ◽  
Christoph Syldatk ◽  
...  

Background: The bacterial community responses to oil spill events are key elements to predict the fate of hydrocarbon pollution in receiving aquatic environments. In polar systems, cold temperatures and low irradiance levels can limit the effectiveness of contamination removal processes. In this study, the effects of a simulated acute oil spillage on bacterial communities from polar sediments were investigated, by assessing the role of hydrocarbon mixture, incubation time and source bacterial community in selecting oil-degrading bacterial phylotypes. Methods: The bacterial hydrocarbon degradation was evaluated by gas chromatography. Flow cytometric and fingerprinting profiles were used to assess the bacterial community dynamics over the experimental incubation time. Results: Direct responses to the simulated oil spill event were found from both Arctic and Antarctic settings, with recurrent bacterial community traits and diversity profiles, especially in crude oil enrichment. Along with the dominance of Pseudomonas spp., members of the well-known hydrocarbon degraders Granulosicoccus spp. and Cycloclasticus spp. were retrieved from both sediments. Conclusions: Our findings indicated that polar bacterial populations are able to respond to the detrimental effects of simulated hydrocarbon pollution, by developing into a more specialized active oil degrading community.


2020 ◽  
Vol 96 (10) ◽  
Author(s):  
Daniyal Gohar ◽  
Mari Pent ◽  
Kadri Põldmaa ◽  
Mohammad Bahram

ABSTRACT Increasing evidence suggest that bacteria form diverse communities in various eukaryotic hosts, including fungi. However, little is known about their succession and the functional potential at different host development stages. Here we examined the effect of fruiting body parts and developmental stages on the structure and potential function of fungus-associated bacterial communities. Using high-throughput sequencing, we characterized bacterial communities and their associated potential functions in fruiting bodies from ten genera belonging to four major mushroom-forming orders and three different developmental stages of a model host species Cantharellus cibarius. Our results demonstrate that bacterial community structure differs between internal and external parts of the fruiting body but not between inner tissues. The structure of the bacterial communities showed significant variation across fruiting body developmental stages. We provide evidence that certain functional groups, such as those related to nitrogen fixation, persist in fruiting bodies during the maturation, but are replaced by putative parasites/pathogens afterwards. These data suggest that bacterial communities inhabiting fungal fruiting bodies may play important roles in their growth and development.


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