scholarly journals Glutamic acid reshapes the plant microbiota to protect plants against pathogens

Microbiome ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Da-Ran Kim ◽  
Chang-Wook Jeon ◽  
Gyeongjun Cho ◽  
Linda S. Thomashow ◽  
David M. Weller ◽  
...  
Keyword(s):  
Microbial Community ◽  
Population Density ◽  
Glutamic Acid ◽  
In Planta ◽  
Natural Context ◽  
Population Sizes ◽  
Plant Microbiota ◽  
Loss Of Diversity ◽  
Microbial Symbionts ◽  
Plant Microbiome

Abstract Background Plants in nature interact with other species, among which are mutualistic microorganisms that affect plant health. The co-existence of microbial symbionts with the host contributes to host fitness in a natural context. In turn, the composition of the plant microbiota responds to the environment and the state of the host, raising the possibility that it can be engineered to benefit the plant. However, technology for engineering the structure of the plant microbiome is not yet available. Results The loss of diversity and reduction in population density of Streptomyces globisporus SP6C4, a core microbe, was observed coincident with the aging of strawberry plants. Here, we show that glutamic acid reshapes the plant microbial community and enriches populations of Streptomyces, a functional core microbe in the strawberry anthosphere. Similarly, in the tomato rhizosphere, treatment with glutamic acid increased the population sizes of Streptomyces as well as those of Bacillaceae and Burkholderiaceae. At the same time, diseases caused by species of Botrytis and Fusarium were significantly reduced in both habitats. We suggest that glutamic acid directly modulates the composition of the microbiome community. Conclusions Much is known about the structure of plant-associated microbial communities, but less is understood about how the community composition and complexity are controlled. Our results demonstrate that the intrinsic level of glutamic acid in planta is associated with the composition of the microbiota, which can be modulated by an external supply of a biostimulant.

Modulation of Gut Microbiota through Dietary Phytochemicals as a Novel Anti-infective Strategy

2020 ◽  
Vol 17 (4) ◽  
pp. 498-506 ◽  
Author(s):  
Pavan K. Mujawdiya ◽  
Suman Kapur
Keyword(s):  
Microbial Community ◽  
Quorum Sensing ◽  
Population Density ◽  
Gut Microbiota ◽  
Biofilm Formation ◽  
Chemical Interaction ◽  
Bacterial Species ◽  
Critical Role ◽  
Bacterial Cells ◽  
Gut Microbes

: Quorum Sensing (QS) is a phenomenon in which bacterial cells communicate with each other with the help of several low molecular weight compounds. QS is largely dependent on population density, and it triggers when the concentration of quorum sensing molecules accumulate in the environment and crosses a particular threshold. Once a certain population density is achieved and the concentration of molecules crosses a threshold, the bacterial cells show a collective behavior in response to various chemical stimuli referred to as “auto-inducers”. The QS signaling is crucial for several phenotypic characteristics responsible for bacterial survival such as motility, virulence, and biofilm formation. Biofilm formation is also responsible for making bacterial cells resistant to antibiotics. : The human gut is home to trillions of bacterial cells collectively called “gut microbiota” or “gut microbes”. Gut microbes are a consortium of more than 15,000 bacterial species and play a very crucial role in several body functions such as metabolism, development and maturation of the immune system, and the synthesis of several essential vitamins. Due to its critical role in shaping human survival and its modulating impact on body metabolisms, the gut microbial community has been referred to as “the forgotten organ” by O`Hara et al. (2006) [1]. Several studies have demonstrated that chemical interaction between the members of bacterial cells in the gut is responsible for shaping the overall microbial community. : Recent advances in phytochemical research have generated a lot of interest in finding new, effective, and safer alternatives to modern chemical-based medicines. In the context of antimicrobial research various plant extracts have been identified with Quorum Sensing Inhibitory (QSI) activities among bacterial cells. This review focuses on the mechanism of quorum sensing and quorum sensing inhibitors isolated from natural sources.

scholarly journals The Impact of Health Policies and Sociodemographic Factors on Doubling Time of the COVID-19 Pandemic in Mexico

2021 ◽  
Vol 18 (5) ◽  
pp. 2354
Author(s):  
Lina Díaz-Castro ◽  
Héctor Cabello-Rangel ◽  
Kurt Hoffman
Keyword(s):  
Population Density ◽  
Doubling Time ◽  
Sociodemographic Factors ◽  
Health Policies ◽  
Government Response ◽  
University Of Oxford ◽  
Negative Effect ◽  
Population Sizes ◽  
The University ◽  
The Impact

Background. The doubling time is the best indicator of the course of the current COVID-19 pandemic. The aim of the present investigation was to determine the impact of policies and several sociodemographic factors on the COVID-19 doubling time in Mexico. Methods. A retrospective longitudinal study was carried out across March–August, 2020. Policies issued by each of the 32 Mexican states during each week of this period were classified according to the University of Oxford Coronavirus Government Response Tracker (OxCGRT), and the doubling time of COVID-19 cases was calculated. Additionally, variables such as population size and density, poverty and mobility were included. A panel data model was applied to measure the effect of these variables on doubling time. Results. States with larger population sizes issued a larger number of policies. Delay in the issuance of policies was associated with accelerated propagation. The policy index (coefficient 0.60, p < 0.01) and the income per capita (coefficient 3.36, p < 0.01) had a positive effect on doubling time; by contrast, the population density (coefficient −0.012, p < 0.05), the mobility in parks (coefficient −1.10, p < 0.01) and the residential mobility (coefficient −4.14, p < 0.01) had a negative effect. Conclusions. Health policies had an effect on slowing the pandemic’s propagation, but population density and mobility played a fundamental role. Therefore, it is necessary to implement policies that consider these variables.

scholarly journals Considerations for Verticillium Wilt Resistance Evaluation in Potato

Plant Disease ◽  
2007 ◽  
Vol 91 (4) ◽  
pp. 360-367 ◽  
Author(s):  
K. E. Frost ◽  
D. I. Rouse ◽  
S. H. Jansky
Keyword(s):  
Disease Severity ◽  
Verticillium Wilt ◽  
Yield Loss ◽  
Control Culture ◽  
In Planta ◽  
Disease Symptoms ◽  
Accuracy And Precision ◽  
Population Sizes ◽  
Pathogen Colonization ◽  
Time Accuracy

Verticillium wilt (Vw), caused by the soilborne fungi Verticillium dahliae and V. albo-atrum, is an important disease of potato (Solanum tuberosum). Host plant resistance is a promising method of Vw control. Culture-based methods that quantify the pathogen in host tissue often are used for Vw resistance screening. To evaluate the processing time, accuracy, and precision of these methods, 46 clones were planted in a field naturally infested with V. dahliae to collect data on visual disease symptoms, pathogen colonization, and yield. In 2002, disease severity explained 4.34% of the variability of yield loss, but the linear relationship between stem colonization and yield loss was not significant. In 2003, stem colonization explained 57.5% of the variability of yield loss, whereas disease severity explained 1.7% of the variability of yield loss. Correlations comparing clone ranks from repeated pathogen measurements indicated that culturing sap from individual stems or bulked stems generated more repeatable clone rankings than culturing dried stems. Clone rankings were more repeatable between years if pathogen measurements were made earlier in the growing season. The results indicate a need to characterize the effect of the environment on the relationship among pathogen population sizes in planta, disease symptoms, and yield loss.

scholarly journals An ancient antimicrobial protein co-opted by a fungal plant pathogen for in planta mycobiome manipulation

2021 ◽  
Author(s):  
Nick Snelders ◽  
Gabriella Petti ◽  
Grardy van den Berg ◽  
Michael Seidl ◽  
Bart Thomma
Keyword(s):  
Life Stage ◽  
Antibacterial Properties ◽  
Plant Evolution ◽  
Effector Proteins ◽  
Plant Colonization ◽  
Antimicrobial Protein ◽  
In Planta ◽  
Antimicrobial Proteins ◽  
Pathogenic Microbes ◽  
Plant Microbiome

Microbes typically secrete a plethora of molecules to promote niche colonization. Soil-dwelling microbes are well-known producers of antimicrobials that are exploited to outcompete microbial co-inhabitants. Also plant pathogenic microbes secrete a diversity of molecules into their environment for niche establishment. Upon plant colonization, microbial pathogens secrete so-called effector proteins that promote disease development. While such effectors are typically considered to exclusively act through direct host manipulation, we recently reported that the soil-borne fungal xylem-colonizing vascular wilt pathogen Verticillium dahliae exploits effector proteins with antibacterial properties to promote host colonization through the manipulation of beneficial host microbiota. Since fungal evolution preceded land plant evolution, we now speculate that a subset of the pathogen effectors involved in host microbiota manipulation evolved from ancient antimicrobial proteins of terrestrial fungal ancestors that served in microbial competition prior to the evolution of plant pathogenicity. Here, we show that V. dahliae has co-opted an ancient antimicrobial protein as effector, named VdAMP3, for mycobiome manipulation in planta. We show that VdAMP3 is specifically expressed to ward off fungal niche competitors during resting structure formation in senescing mesophyll tissues. Our findings indicate that effector-mediated microbiome manipulation by plant pathogenic microbes extends beyond bacteria and also concerns eukaryotic members of the plant microbiome. Finally, we demonstrate that fungal pathogens can exploit plant microbiome-manipulating effectors in a life-stage specific manner, and that a subset of these effectors has evolved from ancient antimicrobial proteins of fungal ancestors that likely originally functioned in manipulation of terrestrial biota.

The 73-kb pIAA plasmid increases competitive fitness of Pseudomonas syringae subspecies savastanoi in oleander

1993 ◽  
Vol 39 (7) ◽  
pp. 659-664 ◽  
Author(s):  
Sara E. Silverstone ◽  
David G. Gilchrist ◽  
Richard M. Bostock ◽  
Tsune Kosuge
Keyword(s):  
Population Density ◽  
Pseudomonas Syringae ◽  
Indoleacetic Acid ◽  
Leaf Tissue ◽  
Insertion Mutant ◽  
Wild Type ◽  
In Planta ◽  
Bacterial Strains ◽  
Growth And Survival ◽  
Iaa Production

Pseudomonas syringae subsp. savastanoi causes tumors on olive and oleander by producing the plant growth regulators indoleacetic acid (IAA) and cytokinins following infection of the plant. The contribution of IAA production to the ability of P. syringae subsp. savastanoi to grow and survive in oleander leaf tissue was studied. Bacterial strains differing only with respect to IAA production were characterized. Growth and survival of wild-type and two mutant strains of P. syringae subsp. savastanoi in oleander leaf tissue were monitored by weekly colony counts and IAA plate assays. Growth rate of the three strains in culture and in planta did not differ significantly. However, the wild-type strain reached a higher population density and maintained its maximum density at least 9 weeks longer than either mutant population. An insertion mutant containing the IAA plasmid (pIAA), but incapable of IAA production, did not maintain a higher population density than a strain cured of the IAA plasmid. The pIAA-cured strain maintained a higher population density when coinoculated with an IAA-producing strain than when inoculated alone. These results suggest that IAA production may contribute to the fitness of P. syringae subsp. savastanoi in oleander tissue and that the iaa operon alone may be responsible for the competitive advantage of cells harboring pIAA.Key words: indoleacetic acid, bacterial ecology.

scholarly journals KEPADATAN DAN DISTRIBUSI UKURAN IKAN NAPOLEON (Cheilinus undulatus) DI PERAIRAN KARANG BUTON DAN WAKATOBI, SULAWESI TENGGARA

2017 ◽  
Vol 23 (2) ◽  
pp. 131
Author(s):  
Isa Nagib Edrus ◽  
Kris Handoko
Keyword(s):  
Population Density ◽  
Length Distribution ◽  
Density Level ◽  
Visual Census ◽  
Underwater Visual Census ◽  
Endangered Fish ◽  
Additional Tool ◽  
The Status ◽  
Population Sizes

Kajian tentang ukuran populasi ikan napoleon (Cheilinus undulatus) merupakan bagian dari upaya pengelolaan sumberdaya ikan rawan punah. Penelitian ikan napoleon dilaksanakan di perairan karang Kabupaten Buton (2014) dan Wakatobi (2016). Tujuan penelitian untuk mengidentifikasi kepadatan populasi napoleon dan distribusi frekuensi panjang ikan napoleon. Metode pengambilan data yang digunakan adalah Underwater Visual Census (UVC) dengan alat bantu GPS-ploating Kit sebagai penentu luas area sensus. Jumlah individu ikan napoleon yang ditemukan dalam satuan luas area sensus dihitung sebagai kepadatan. Hasil penelitian menunjukkan bahwa kepadatan ikan napoleon di Buton dan Wakatobi masing-masing 0,76 dan 0,93 individu /ha. Nilai kepadatan ikan napoleon masuk kategori kritis dengan tingkat kepadatan sedang. Ukuran ikan anakan napoleon cukup banyak di Buton (26 %) dan ukuran dewasa terbanyak (100 %) dijumpai di Wakatobi, yaitu antara 30 – 50 cm. Ukuran ini termasuk dalam ukuran terlarang panen.  Assessing the population sizes of humphead warasse (Cheilinus undulatus) is vital to manage an endangered fish resource. This research aims to examine the population density and length distribution. This study was carried out at reef waters of Buton (2014) and Wakatobi (2016). A method used in data colection is underwater vicual census (UVC). The GPS-ploating Kid used as additional tool to record sensus areas. Results show that densities of humphead warasse in Buton and Wakatobi were 0.76 and 093 individual per hectar, respectively.  The status was critical and a fair density level. In Buton domined by juvenile (15) valued about 26 %. While, in Wakatobi domined by larger size (30 to 50 cm). However, both size was forbidden for exploiding.

scholarly journals Screening of cucumber (Cucumis sativus L.) cultivars against southern root knot nematode, Meloidogyne incognita (Kofoid and White) Chitwood

2020 ◽  
Vol 49 (3) ◽  
pp. 579-584
Author(s):  
Ifra Siddique ◽  
Ishrat Naz ◽  
Raja Asad Ali Khan ◽  
Musharaf Ahmed ◽  
Syeda Maryam Hussain
Keyword(s):  
Population Density ◽  
Meloidogyne Incognita ◽  
Growth Parameters ◽  
High Population Density ◽  
In Planta ◽  
Root Knot Nematode ◽  
Cucumis Sativus L ◽  
Southern Root Knot Nematode ◽  
Moderately Resistant ◽  
Significant Mortality

Fourteen cultivars of cucumber were screened for their resistance to the Southern root-knot nematode, Meloidogyne incognita (Kofoid and White) Chitwood in an in planta experiment. The pots were maintained in greenhouse with CRD for 50 days after inoculation. The cultivar DS92-05 induced significant mortality and was rated “moderately resistant (MR)”. This cultivar showed increase in plant growth parameters including vine length. The cultivars DS92-06, Laghman, Sultan and Desitype were moderately susceptible (MS). The cultivar Rehan and DS96-299 were rated susceptible (S) whereas DS97-299, Chaiya, Beitalpha, Alto, DS92-04 and Local were rated as highly susceptible (HS). DS92-05 is thus promising for sustainable agriculture, specially in those areas with high population density of Southern Root knot nematode.

scholarly journals Dissecting the co-transcriptome landscape of plants and microbiota members

2021 ◽  
Author(s):  
Tatsuya Nobori ◽  
Yu Cao ◽  
Frederickson Entila ◽  
Eik Dahms ◽  
Yayoi Tsuda ◽  
...  
Keyword(s):  
Pathogenic Bacteria ◽  
Early Stage ◽  
Building Blocks ◽  
Niche Separation ◽  
In Planta ◽  
Bacterial Strains ◽  
Transcriptional Responses ◽  
Associated Bacteria ◽  
Plant Microbiota ◽  
And Function

AbstractInteractions between plants and each neighboring microbial species are fundamental building blocks that collectively determine the structure and function of the plant microbiota, but the molecular basis of such interactions is poorly characterized. Here, we monocolonized Arabidopsis leaves with nine plant-associated bacteria from all major phyla of the plant microbiota and profiled co-transcriptomes of plants and bacteria. These strains elicited quantitatively different plant transcriptional responses including typical pattern-triggered immunity responses. Genes of non-pathogenic bacteria involved in general metabolism and energy production were commonly suppressed in planta in contrast to a virulent pathogen. Various nutrient acquisition pathways that are frequently encoded in the genomes of plant-associated bacteria were induced in planta in a strain-specific manner, shedding light on bacterial adaptation to the plant environment and identifying a potential driving force of niche separation. Integrative analyses of plant and bacterial transcriptomes suggested that the transcriptional reprogramming of plants is largely uncoupled from that of bacteria at an early stage of interactions. This study provides insights into how plants discriminate among bacterial strains and sets the foundation for in-depth mechanistic dissection of plant-microbiota interactions.

scholarly journals The epidemiological trends of coronavirus disease (COVID-19) in Iran: February 19 to March 22, 2020

2020 ◽  
Author(s):  
Farzan Madadizadeh ◽  
Reyhane Sefidkar
Keyword(s):  
Population Density ◽  
Cross Sectional Study ◽  
Influential Factors ◽  
Personal Hygiene ◽  
Cross Sectional ◽  
Health Authorities ◽  
Population Sizes ◽  
High Level ◽  
Epidemiological Trends ◽  
Very High

Abstract Background The Coronavirus has crossed the geographical borders of various countries without any restrictions. This study was performed to identify the epidemiological trends of coronavirus disease (COVID-19) in Iran during February 19 to March 22, 2020.Methods This cross sectional study was carried out in 31 provinces by using the daily number of newly infected cases which was announced by the Iranian health authorities from February 19 to March 22, 2020, we explore the trend of outbreak of coronavirus disease in all provinces of Iran and determine some influential factors such as population size, area, population density, distance from original epicenter, altitude, and human development index (HDI) for each province on its spread by Spearman correlation coefficient. K-means cluster analysis (KMCA) also categorized the provinces into 10 separate groups based on CF and ACF of the infected cases at the end of the study period. (ACF).Results There were 21,638 infected, 7,913 recovered and 2,299 death cases with COVID-19 in Iran during the study period. By March 22, CF shows that, most cases are attributed to Tehran province, while ACF shows that most are attributed to Semnan province. There was a positive significant correlation between CF of the infected cases and province population sizes (r=0.45), HDI (r=0.58); province population density (r=0.47); a negative significant correlation between the CF of the infected cases and distance from original epicenter (r=-0.47). KMCA results based on CF showed very high level of outbreak was in Tehran while KMCA based on ACF showed very high level of outbreak were in Semnan and Qom provinces.Conclusions Special attention is needed for the provinces nearer to the original epicenter which are high risk spots in terms of the severe prevalence of COVID-19. In the absence of definite treatment for this infectious disease, the effective solutions to reduce the transmission of the disease are early isolation of the cases, quarantine for close contacts both in families and community and observing personal hygiene.

scholarly journals Effect of foundress population density and size on reproduction and population growth of a haplodiploid mite

2020 ◽  
Vol 25 (11) ◽  
pp. 2063-2076
Author(s):  
Nuwan Weerawansha ◽  
Qiao Wang ◽  
Xiong Zhao He
Keyword(s):  
Population Density ◽  
Population Growth ◽  
Intrinsic Rate ◽  
Adaptive Strategy ◽  
Food Competition ◽  
Intrinsic Rate Of Increase ◽  
Vegetable Crops ◽  
Rate Of Increase ◽  
Population Sizes ◽  
Pest Mite

Tetranychus ludeni Zacher (Acari: Tetranychidae) is an invasive polyphagous haplodiploid pest mite of many vegetable crops in many parts of the world. This study investigated the effects of simultaneous variations in the local foundress population density and size on the reproduction and population growth of T. ludeni. We show that negative population-density and -size dependency limited the reproduction of foundresses, where the effects of population size on population growth overweighed that of population density. We further demonstrate that ovipositing females could accelerate population growth rate (intrinsic rate of increase, rm) at higher population sizes by producing more daughters early during their lifespan, which can be an adaptive strategy to allow more daughters to complete development and disperse to reduce future food competition intensity. This study provided knowledge on population dynamics in response to foundress population density and size in general and T. ludeni population forecast and precise timing of pest management in particular.

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