scholarly journals Pathogenesis of Fungal and Bacterial Microbes

Pathogens ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 602
Author(s):  
Jennifer Geddes-McAlister

The pathogenesis of fungal and bacterial microbes is a complex process involving distinct parameters, including virulence factors, nutrient sensing and availability, microbial signals, as well as host status and defense responses. Defining pathogenesis improves our understanding of how an organism causes diseases and provides insight into novel prospects to combat infection. The effects of pathogenic microbes have significant impact on diverse sectors, including health, agriculture, and economics, underscoring their immense importance in society. Articles in this Special Issue address unique aspects of microbial pathogenesis by exploring interactions between host and pathogen during infection, defining inflammatory immune responses, profiling the importance of essential microbial structures associated with virulence, and outlining critical considerations driving complex diseases.

2020 ◽  
Vol 27 (20) ◽  
pp. 3330-3345
Author(s):  
Ana G. Rodríguez-Hernández ◽  
Rafael Vazquez-Duhalt ◽  
Alejandro Huerta-Saquero

Nanomaterials have become part of our daily lives, particularly nanoparticles contained in food, water, cosmetics, additives and textiles. Nanoparticles interact with organisms at the cellular level. The cell membrane is the first protective barrier against the potential toxic effect of nanoparticles. This first contact, including the interaction between the cell membranes -and associated proteins- and the nanoparticles is critically reviewed here. Nanoparticles, depending on their toxicity, can cause cellular physiology alterations, such as a disruption in cell signaling or changes in gene expression and they can trigger immune responses and even apoptosis. Additionally, the fundamental thermodynamics behind the nanoparticle-membrane and nanoparticle-proteins-membrane interactions are discussed. The analysis is intended to increase our insight into the mechanisms involved in these interactions. Finally, consequences are reviewed and discussed.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mari Kurokawa ◽  
Masataka Nakano ◽  
Nobutaka Kitahata ◽  
Kazuyuki Kuchitsu ◽  
Toshiki Furuya

AbstractMicroorganisms that activate plant immune responses have attracted considerable attention as potential biocontrol agents in agriculture because they could reduce agrochemical use. However, conventional methods to screen for such microorganisms using whole plants and pathogens are generally laborious and time consuming. Here, we describe a general strategy using cultured plant cells to identify microorganisms that activate plant defense responses based on plant–microbe interactions. Microbial cells were incubated with tobacco BY-2 cells, followed by treatment with cryptogein, a proteinaceous elicitor of tobacco immune responses secreted by an oomycete. Cryptogein-induced production of reactive oxygen species (ROS) in BY-2 cells served as a marker to evaluate the potential of microorganisms to activate plant defense responses. Twenty-nine bacterial strains isolated from the interior of Brassica rapa var. perviridis plants were screened, and 8 strains that enhanced cryptogein-induced ROS production in BY-2 cells were selected. Following application of these strains to the root tip of Arabidopsis seedlings, two strains, Delftia sp. BR1R-2 and Arthrobacter sp. BR2S-6, were found to induce whole-plant resistance to bacterial pathogens (Pseudomonas syringae pv. tomato DC3000 and Pectobacterium carotovora subsp. carotovora NBRC 14082). Pathogen-induced expression of plant defense-related genes (PR-1, PR-5, and PDF1.2) was enhanced by the pretreatment with strain BR1R-2. This cell–cell interaction-based platform is readily applicable to large-scale screening for microorganisms that enhance plant defense responses under various environmental conditions.


Plants ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1261
Author(s):  
Robin Lardon ◽  
Danny Geelen

Plant regeneration is essential for survival upon wounding and is, hence, considered to be a strong natural selective trait. The capacity of plant tissues to regenerate in vitro, however, varies substantially between and within species and depends on the applied incubation conditions. Insight into the genetic factors underlying this variation may help to improve numerous biotechnological applications that exploit in vitro regeneration. Here, we review the state of the art on the molecular framework of de novo shoot organogenesis from root explants in Arabidopsis, which is a complex process controlled by multiple quantitative trait loci of various effect sizes. Two types of factors are distinguished that contribute to natural regenerative variation: master regulators that are conserved in all experimental systems (e.g., WUSCHEL and related homeobox genes) and conditional regulators whose relative role depends on the explant and the incubation settings. We further elaborate on epigenetic variation and protocol variables that likely contribute to differential explant responsivity within species and conclude that in vitro shoot organogenesis occurs at the intersection between (epi) genetics, endogenous hormone levels, and environmental influences.


2021 ◽  
Author(s):  
Bowen Li ◽  
Adhimoolam Karthikeyan ◽  
Liqun Wang ◽  
Jinlong Yin ◽  
Tongtong Jin ◽  
...  

Abstract Background: Soybean mosaic virus (SMV) is the most devastating pathogen of soybean. MicroRNAs (miRNAs) are a class of non-coding RNAs (21-24 nucleotides) and play important roles in regulating defense responses against pathogens. However, miRNA's response to SMV in soybean is not as well documented. Result: In this study, we analyzed 18 miRNA libraries, including three biological replicates from two soybean lines (Resistant and susceptible lines to SMV strain SC3 selected from the near-isogenic lines of Qihuang No. 1× Nannong1138-2) after virus infection at three different time intervals (0 dpi, 7 dpi, and 14 dpi). A total of 1,092 miRNAs, including 608 known miRNAs and 484 novel miRNAs were detected. Differential expression analyses identified the miRNAs responded during soybean-SMV interaction. Then, miRNAs potential target genes were predicted via data mining, and functional annotation was done by Gene Ontology (GO) analysis. Eventually, the expression patterns of several miRNAs validated by quantitative real-time PCR analysis are consistent with sequencing results. Conclusion: We have identified a large number of miRNAs and their target genes and also functional annotations. Our study provides additional information on soybean miRNAs and an insight into the role of miRNAs during SMV-infection in soybean.


2011 ◽  
Vol 1 (5) ◽  
pp. 1-2
Author(s):  
Lavkush Dwivedi

Infectious diseases and consequent immune imbalancesare major constraint in human health managementthroughout the world. However, in recentdecades enormous efforts have been made to elucidatethe immunomodulatory approaches againstinfectious diseases. Immunomodulation is a therapeuticapproach in which we try to intervene inauto regulating processes of the defense system toadjust the immune response at a desired level.The present special issue on cutting edge issues inImmunomodulation like Immune stimulation, Immunesuppression, Immune potentiating and immunereinforcement summarizes our current understandingof this complex mosaic. The accompanyingselection of recent articles from across theworld provides further insight into this topic. 


2015 ◽  
Vol 10 (12) ◽  
pp. e1049791 ◽  
Author(s):  
Deepak Bhardwaj ◽  
Anna Medici ◽  
Alain Gojon ◽  
Benoît Lacombe ◽  
Narendra Tuteja

2021 ◽  
Author(s):  
Bhoomi Madhu ◽  
Tina L. Gumienny

Innate immunity in animals is orchestrated by multiple cell signaling pathways, including the TGF-β; superfamily pathway. While the role of TGF-β signaling in innate immunity has been clearly identified, the requirement for this pathway in generating specific, robust responses to different bacterial challenges has not been characterized. Here, we address the role of DBL-1/TGF-β in regulating signature host defense responses to a wide range of bacteria in C. elegans. This work reveals a role of DBL-1/TGF-β in animal survival, organismal behaviors, and molecular responses in different environments. Additionally, we identify a novel role for SMA-4/Smad that suggests both DBL-1/TGF-β-dependent and -independent functions in host avoidance responses. RNA-seq analyses and immunity reporter studies indicate DBL-1/TGF-β differentially regulates target gene expression upon exposure to different bacteria. Furthermore, the DBL-1/TGF-β pathway is itself differentially affected by the bacteria exposure. Collectively, these findings demonstrate bacteria-specific host immune responses regulated by the DBL-1/TGF-β signaling pathway.


2020 ◽  
Author(s):  
Shi Yu ◽  
Delasa Aghamirzaie ◽  
Kim Harich ◽  
Eva Collakova ◽  
Ruth Grene ◽  
...  

ABSTRACTAmino acid homeostasis in plants is finely tuned to match developmental needs and response to adverse environments. Over-expression of the single-transmembrane domain protein GLUTAMINE DUMPER1 (GDU1) leads to increased amino acid export, reduced growth and constitutive induction of immune responses. We used an inducible gene expression system to tease apart the primary and secondary effects caused by GDU1, and demonstrated that the primary effect is increasing amino acid export, followed by increased amino acid content and abscisic acid (ABA) response, and a subsequent activation of defense responses. The GDU1-mediated hypersensitivity to ABA partially depended on the E3 ubiquitin ligase LOSS-OF-GDU1 2 (LOG2), a known GDU1 interactor. More importantly, the lysine catabolite pipecolic acid played a pivotal role in the GDU1-induced defense responses. This work unravels a novel relationship between amino acid transport, ABA and defense responses, potentially mediated by the GDU1-LOG2 complex, critical for understanding how plants respond to amino acid imbalance.ONE SENTENCE SUMMARYGenetically induced disturbance of amino acid homeostasis sequentially triggers responses to abiotic stresses and plant defenses to pathogens in Arabidopsis through undefined sensing mechanisms


As the world becomes a globalised economic network, cross-country knowledge transfer is an emerging phenomenon. It happens not only through Multi-National Corporations (MNC) or joint ventures, but also in dispersed organizations or individuals. Knowledge transfer is a critical part of knowledge management and is a complex process that is affected by many factors. Research into knowledge sharing and transfer within an organisation (intra) and between organisations (inter) has produced useful insight into the process and the model of effective knowledge transfer, and the factors affecting such a process. Knowledge transfer across different countries – refers to transnational knowledge transfer (TKT) thereafter, has emerged as a new domain of knowledge management that attracted many researchers. However, the findings on TKT are disproportionate comparing to ample evidence on intra and inter organisational knowledge transfer. It is anticipated that TKT has its own unique features and cannot be simply classified as one of the commonly accepted knowledge transfer categorizations. Therefore, specific attention should be paid to examine knowledge transfer in a cross-country context.


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