Introduction: disease resistance in plants

1972 ◽  
Vol 181 (1064) ◽  
pp. 213-232 ◽  
Keyword(s):  
Higher Plants ◽  
Hypersensitive Reaction ◽  
Host Cells ◽  
Cell Wall Degrading Enzymes ◽  
General Terms ◽  
Bacteria And Fungi ◽  
The One ◽  
Almost All ◽  
Host Parasite

This paper discusses in general terms the mechanisms proposed to explain the resistance of higher plants to infection and colonization by bacteria and fungi, especially the type of resistance associated with rapid killing of host cells and very limited growth of the pathogen; that is, with the hypersensitive reaction of the plant to infection (h.r.). The main points considered are: the significance of the h.r. for obligate and other types of parasites; the nature of the h.r. and the means by which it is invoked; the absence of the h.r in compatible host-parasite combinations; the h.r. and the production of phytoalexins, and the role of the latter in resistance; the part played by cell-wall degrading enzymes in the earliest stages of infection; the relation between the h.r. in interactions between races of a pathogen and different forms of a host species, on the one hand, and the resistance of all plants to almost all pathogens, on the other. Also discussed is the less specific but important type of resistance in which the pathogen continues to grow in resistant plants more slowly than in susceptible plants.

scholarly journals Functional analysis of the putative antiapoptotic genes, p49 and iap4, of Spodoptera litura nucleopolyhedrovirus with RNAi

2008 ◽  
Vol 89 (8) ◽  
pp. 1873-1880 ◽  
Author(s):  
Qian Yu ◽  
Tiehao Lin ◽  
Guozhong Feng ◽  
Kai Yang ◽  
Yi Pang
Keyword(s):  
Spodoptera Litura ◽  
Virus Production ◽  
Host Cells ◽  
Homology Search ◽  
Pcr Analysis ◽  
Viability Analysis ◽  
Infected Cells ◽  
Budded Virus ◽  
Almost All

A homology search of a public database revealed that Spodoptera litura nucleopolyhedrovirus (SpltNPV) possesses two putative, antiapoptotic genes, p49 and inhibitor of apoptosis 4 (iap4), but their function has not been investigated in its native host cells. In the present study, we used RNA interference (RNAi) to silence the expression of Splt-iap4 and Splt-p49, independently or together, to determine their roles during the SpltNPV life cycle. RT-PCR analysis and Western blot analysis showed the target gene expression had been knocked out in the SpltNPV-infected SpLi-221 cells after treatment with Splt-p49 or Splt-iap4 double-stranded RNA (dsRNA), respectively, confirming that the two genes were effectively silenced. In SpltNPV-infected cells treated with Splt-p49 dsRNA, apoptosis was observed beginning at 14 h, and almost all cells had undergone apoptosis by 48 h. In contrast, budded virus production and polyhedra formation progressed normally in infected cells treated with Splt-iap4 dsRNA. Cell viability analysis showed that Splt-IAP4 had no synergistic effect on the inhibition of apoptosis of SpLi-221 cells induced by SpltNPV infection. Interestingly, after Splt-iap4 dsRNA treatment, cells did not congregate like those infected with SpltNPV in the early infection phase, implying an unknown role of baculovirus iap4. Our results determine that Splt-p49 is necessary to prevent apoptosis; however, Splt-iap4 has no antiapoptotic function during SpltNPV infection.

scholarly journals Pathways from marine protected area design and management to ecological success

PeerJ ◽  
2015 ◽  
Vol 3 ◽  
pp. e1424 ◽  
Author(s):  
Murray A. Rudd
Keyword(s):  
Marine Protected Area ◽  
Theoretic Approach ◽  
Negative Results ◽  
Complex Interactions ◽  
General Terms ◽  
Ecological Performance ◽  
Ecological Isolation ◽  
Ecological Success ◽  
The One

Using an international dataset compiled from 121 sites in 87 marine protected areas (MPAs) globally (Edgar et al., 2014), I assessed how various configurations of design and management conditions affected MPA ecological performance, measured in terms of fish species richness and biomass. The set-theoretic approach used Boolean algebra to identify pathways that combined up to five ‘NEOLI’ (No-take,Enforced,Old,Large,Isolated) conditions and that were sufficient for achieving positive, and negative, ecological outcomes. Ecological isolation was overwhelming the most important condition affecting ecological outcomes butOldandLargewere also conditions important for achieving high levels of biomass among large fishes (jacks, groupers, sharks). Solution coverage was uniformly low (<0.35) for all models of positive ecological performance suggesting the presence of numerous other conditions and pathways to ecological success that did not involve the NEOLI conditions. Solution coverage was higher (>0.50) for negative results (i.e., the absence of high biomass) among the large commercially-exploited fishes, implying asymmetries in how MPAs may rebuild populations on the one hand and, on the other, protect against further decline. The results revealed complex interactions involving MPA design, implementation, and management conditions that affect MPA ecological performance. In general terms, the presence of no-take regulations and effective enforcement were insufficient to ensure MPA effectiveness on their own. Given the central role of ecological isolation in securing ecological benefits from MPAs, site selection in the design phase appears critical for success.

scholarly journals Silver Nanoparticles as Potential Antiviral Agents

Pharmaceutics ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2034
Author(s):  
Zubair Ahmed Ratan ◽  
Fazla Rabbi Mashrur ◽  
Anisha Parsub Chhoan ◽  
Sadi Md. Shahriar ◽  
Mohammad Faisal Haidere ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Potential Role ◽  
Viral Infections ◽  
Antiviral Agents ◽  
Host Cells ◽  
Characterization Methods ◽  
New Horizons ◽  
Bacteria And Fungi ◽  
The Impact

Since the early 1990s, nanotechnology has led to new horizons in nanomedicine, which encompasses all spheres of science including chemistry, material science, biology, and biotechnology. Emerging viral infections are creating severe hazards to public health worldwide, recently, COVID-19 has caused mass human casualties with significant economic impacts. Interestingly, silver nanoparticles (AgNPs) exhibited the potential to destroy viruses, bacteria, and fungi using various methods. However, developing safe and effective antiviral drugs is challenging, as viruses use host cells for replication. Designing drugs that do not harm host cells while targeting viruses is complicated. In recent years, the impact of AgNPs on viruses has been evaluated. Here, we discuss the potential role of silver nanoparticles as antiviral agents. In this review, we focus on the properties of AgNPs such as their characterization methods, antiviral activity, mechanisms, applications, and toxicity.

The anatomy of Santalum album (Sandalwood) haustoria

2006 ◽  
Vol 84 (10) ◽  
pp. 1608-1616 ◽  
Author(s):  
Kushan U. Tennakoon ◽  
Duncan D. Cameron
Keyword(s):  
Mass Flow ◽  
Applied Pressure ◽  
Host Cells ◽  
Santalum Album ◽  
Cell Wall Degrading Enzymes ◽  
Hyaline Body ◽  
Direct Pressure ◽  
Xylem Tissue ◽  
Host Parasite ◽  
Santalum Album L

Structural attributes of Santalum album L. (Sandalwood) haustoria have been long overlooked in the literature. This is surprising since successful haustorial formation is key to the survival of individuals of this ecologically and economically important plant. We investigated the morphology of haustoria formed by S. album attached to one of its principal hosts Tithonia diversifolia (Hemsley) A. Gray. The bell-shaped mature haustoria were composed of a peripheral hyaline body and a centrally located penetration peg. The parasite penetration peg can penetrate the host by means of direct pressure and the secretion of cell-wall-degrading enzymes when forming a successful graft union. The latter mechanism is supported by this study as we observed no evidence of collapsed host cells as the result of parasite applied pressure. Upon reaching the xylem tissue of the host root, the penetration peg formed a thin ellipsoidal disc and the host–parasite interface was almost entirely composed of parenchymatous tissue. Luminal continuities were absent between the xylem conducting tissues of the partners, thus suggesting mass flow of solutes is unlikely to occur in this association. High densities of contact parenchyma were found at the host–parasite interface; thus it is probable that these are the principal structures formed by the parasite that facilitate the acquisition of host-derived xylem resources. This study therefore concludes that haustorial anatomy of S. album supports cross membrane (potentially selective) uptake of host-derived solutes as opposed to mass flow via vascular continuity.

scholarly journals Adhesion of Tritrichomonas foetus to Bovine Vaginal Epithelial Cells

1999 ◽  
Vol 67 (8) ◽  
pp. 3847-3854 ◽  
Author(s):  
B. N. Singh ◽  
J. J. Lucas ◽  
D. H. Beach ◽  
S. T. Shin ◽  
R. O. Gilbert
Keyword(s):  
Epithelial Cells ◽  
Cell Surface ◽  
Trichomonas Vaginalis ◽  
Host Cells ◽  
Tritrichomonas Foetus ◽  
Trypan Blue Exclusion ◽  
Vaginal Epithelial Cells ◽  
Host Parasite

ABSTRACT An in vitro culture system of bovine vaginal epithelial cells (BVECs) was developed to study the cytopathogenic effects ofTritrichomonas foetus and the role of lipophosphoglycan (LPG)-like cell surface glycoconjugates in adhesion of parasites to host cells. Exposure of BVEC monolayers to T. foetusresulted in extensive damage of monolayers. Host cell disruption was measured quantitatively by a trypan blue exclusion assay and by release of 3H from [3H]thymidine-labeled host cells. Results indicated contact-dependent cytotoxicity of host cells byT. foetus. The cytopathogenic effect was a function ofT. foetus density. Metronidazole- or periodate-treatedT. foetus showed no damage to BVEC monolayers. A related human trichomonad, Trichomonas vaginalis, showed no cytotoxic effects, indicating species-specific host-parasite interactions. A direct binding assay was developed and used to investigate the role of a major cell surface LPG-like molecule in host-parasite adhesion. The results of competition experiments showed that the binding to BVECs was displaceable, was saturable, and yielded a typical binding curve, suggesting that specific receptor-ligand interactions mediate the attachment of T. foetus to BVECs. Progesterone-treated BVECs showed enhanced parasite binding. T. foetus LPG inhibited the binding of T. foetus to BVECs; the LPG from T. vaginalis and a variety of other glycoconjugates did not. These data imply specificity of LPG on host-parasite adhesion. Periodate-treated parasites showed no adherence to host cells, indicating the involvement of carbohydrate containing molecules in the adhesion process.

scholarly journals FILOSOFI PENDIDIKAN KATOLIK DALAM PERSPEKTIF FILSAFAT ARISTOTELIAN

2019 ◽  
Vol 12 (6) ◽  
pp. 3-18
Author(s):  
Agustinus Wisnu Dewantara
Keyword(s):  
Catholic Education ◽  
Religious Education ◽  
Middle Ages ◽  
Human Life ◽  
Communication Education ◽  
Daily Lives ◽  
Modern Times ◽  
The One ◽  
Almost All

The progress of human civilization today is inseparable from the role of science. The dynamics of the pattern of our daily lives from time to time it runs in line with the dynamics of the development of science. The development of science and human civilization running together since from classical times, the middle ages, modern times, and so on. Novelty found in a period becomes an essential ingredient for other discoveries in the next period. One thing that is difficult to argue is that almost all sides of human life today has been entered by the various effects of the development of science and technology, ranging from economic, political, social and cultural, communication, education, health, and so on. All this progress is the fruit of the development of science that never recede from human studies. This paper on the one hand want to observe the philosophical basis for the world of Catholic education, and on the other hand, this article seeks to contribute a little reflection, especially for teachers of religious education in STKIP Widya Yuwana and Catholic families today. There wilderness philosophy that is so tempting to dive, but the limitations of time and space makes this paper should choose to focus. Perspective selected is Aristotelian philosophy.

scholarly journals Cybersecurity Politics – Conceptualization of the Idea

2021 ◽  
Vol 50 ◽  
pp. 1-19
Author(s):  
Marek Górka ◽  
Keyword(s):  
Political Science ◽  
New Technologies ◽  
Human Life ◽  
The State ◽  
State Institutions ◽  
The One ◽  
Social And Cultural Factors ◽  
Almost All ◽  
Political Economic

The cybersecurity issue discussed in the paper is seen from the perspective of political science with the indication that the subject under discussion concerns the multifaceted nature of the state’s actions, which consists of political, economic, social, and cultural factors. At the same time, the work also intends to prove that cybersecurity is not only a domain of technology because it is the mentioned aspects that shape the conditions of stable development of the state and its citizens in a space dominated by cyber technology in a much more decisive way. Given the growing role of cybertechnology in almost all areas of human life, its importance also forces and inspires political science to question the shape and model of modern policy, which is significantly evolving under the influence of new technologies. On the one hand, emerging cyber threats reveal the weakness of the state and the dependence of state institutions on cybertechnologies, but on the other hand, existing cyber incidents may also motivate many governments to take action to increase the level of cybersecurity.

Holocaust Survival Differentials in the Netherlands, 1942–1945: The Role of Wealth and Nationality

2014 ◽  
Vol 45 (1) ◽  
pp. 1-24
Author(s):  
Marnix Croes
Keyword(s):  
The Netherlands ◽  
Social Economic ◽  
German Jews ◽  
German Occupation ◽  
Economic Class ◽  
The Holocaust ◽  
The One ◽  
Almost All ◽  
Holocaust Survival

Almost all of the 140,000 Jews living in the Netherlands when the German occupation began were sent to transit camps and eventually to death camps, but not on the same timetable. According to the Jews themselves, social-economic class and (pre-war) nationality played an important role in determining when and whether people were sent to meet their death. However, data from the province of Overijssel reveal that Jews from the highest social economic class were, in general, transferred to Westerbork transit camp at a later date than were Jews from lower social-economic classes. Although the usual assumption is that Jews who had more time to find a safe hideout had a better chance to survive the Holocaust, the analysis reveals otherwise. The results for nationality are similar. German Jews from Overijssel were, in general, deported from Westerbork transit camp to the death camps in the East later than were Dutch Jews from the same province. Even though this delay reduced the likelihood that German Jews were sent to a concentration camp that had a survival rate even worse than the one at Auschwitz, German Jews did not survive the Holocaust to a greater extent than did Dutch Jews.

scholarly journals Nocardia species: host-parasite relationships.

1994 ◽  
Vol 7 (2) ◽  
pp. 213-264 ◽  
Author(s):  
B L Beaman ◽  
L Beaman
Keyword(s):  
Soil Microflora ◽  
Host Cells ◽  
Nocardia Asteroides ◽  
Activated Macrophages ◽  
Phagocytic Cells ◽  
Nocardia Species ◽  
Normal Soil ◽  
Host Parasite ◽  
Aerobic Actinomycetes

The nocardiae are bacteria belonging to the aerobic actinomycetes. They are an important part of the normal soil microflora worldwide. The type species, Nocardia asteroides, and N. brasiliensis, N. farcinica, N. otitidiscaviarum, N. nova, and N. transvalensis cause a variety of diseases in both normal and immunocompromised humans and animals. The mechanisms of pathogenesis are complex, not fully understood, and include the capacity to evade or neutralize the myriad microbicidal activities of the host. The relative virulence of N. asteroides correlates with the ability to inhibit phagosome-lysosome fusion in phagocytes; to neutralize phagosomal acidification; to detoxify the microbicidal products of oxidative metabolism; to modify phagocyte function; to grow within phagocytic cells; and to attach to, penetrate, and grow within host cells. Both activated macrophages and immunologically specific T lymphocytes constitute the major mechanisms for host resistance to nocardial infection, whereas B lymphocytes and humoral immunity do not appear to be as important in protecting the host. Thus, the nocardiae are facultative intracellular pathogens that can persist within the host, probably in a cryptic form (L-form), for life. Silent invasion of brain cells by some Nocardia strains can induce neurodegeneration in experimental animals; however, the role of nocardiae in neurodegenerative diseases in humans needs to be investigated.

scholarly journals Robotic renal surgery: The future or a passing curiosity?

2013 ◽  
Vol 3 (3) ◽  
pp. 231 ◽  
Author(s):  
Jeff Warren ◽  
Vitor Da Silva ◽  
Yves Caumartin ◽  
Patrick P.W. Luke
Keyword(s):  
Rapid Evolution ◽  
Publicly Funded ◽  
Renal Surgery ◽  
Living Donor Nephrectomy ◽  
Base De Données ◽  
Néphrectomie Partielle ◽  
Human Participants ◽  
The One ◽  
Almost All

The development, advancement and clinical integration of robotictechnology in surgery continue at a staggering pace. In no otherdiscipline has this rapid evolution occurred to a greater degreethan in urology. Although radical prostatectomy has grown tobecome the prototypical application for the robot, the role of therobot in renal surgery remains controversial. Herein we reviewthe literature on robotic renal surgery. A comprehensive PubMedliterature search was performed to identify all published reportsrelating to robotic renal surgery. All clinically related articlesinvolving human participants were critically appraised in thisreview. Fifty-one clinical articles were included, encompassingrobot-assisted pyeloplasty, nephrectomy, nephroureterectomy,living-donor nephrectomy and partial nephrectomy. Feasibilityhas been shown for each of these procedures. Robot-assisted techniqueshave been described for almost all renal-related procedures.However, the intersect between feasibility and necessityas it pertains to robotic renal surgery has yet to be defined. Also,the high cost of surgical robotic technology mandates criticalappraisal before adoption, especially in a publicly funded healthcare system, such as the one present in Canada.Le développement, le perfectionnement et l’intégration en milieuclinique de la technologie robotique en contexte opératoire sepoursuit à un rythme stupéfiant. Aucune autre discipline n’a vucette évolution rapide à un niveau aussi élevé que l’urologie.Alors que la prostatectomie radicale en est devenue l’applicationprototype, le rôle de la robotique en chirurgie rénale demeurecontroversé. Dans l’article qui suit, nous passons en revue lalittérature portant sur l’emploi de la robotique en chirurgie rénale.Une recherche exhaustive dans la base de données PubMed aété effectuée afin de cerner les rapports sur le sujet. Tous les rapportscliniques portant sur des sujets humains ont été évalués.Cinquante et un articles cliniques ont été inclus dans notreanalyse, incluant des cas, tous assistés par robot, de pyéloplastie,de néphrectomie, de néphro-urétérectomie, de néphrectomiechez des donneurs vivants et de néphrectomie partielle. Pour chacunede ces interventions, la faisabilité a été démontrée. Des techniquesassistées par robot ont été décrites pour pratiquement tousles types d’interventions rénales. Néanmoins, le point d’intersectionentre faisabilité et nécessité concernant l’utilisation de larobotique reste à définir. Par ailleurs, le coût élevé de la robotiquechirurgicale justifie une évaluation critique avant l’adoptionde cette technologie, en particulier dans un système de santépublic comme celui du Canada.

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