scholarly journals First Extensive Microscopic Study of Butternut Defense Mechanisms Following Inoculation with the Canker PathogenOphiognomonia clavigignenti-juglandacearumReveals Compartmentalization of Tissue Damage

2018 ◽  
Vol 108 (11) ◽  
pp. 1237-1252 ◽  
Author(s):  
Danny Rioux ◽  
Martine Blais ◽  
Nicolas Nadeau-Thibodeau ◽  
Marie Lagacé ◽  
Pierre DesRochers ◽  
...  
Keyword(s):  
Cell Walls ◽  
Defense Mechanisms ◽  
Wound Closure ◽  
Histopathological Study ◽  
Native Range ◽  
Juglans Cinerea ◽  
Pathogen Invasion ◽  
Reaction Zones ◽  
Artificial Inoculations ◽  
Asymptomatic Individuals

Ophiognomonia clavigignenti-juglandacearum endangers the survival of butternut (Juglans cinerea) throughout its native range. While screening for disease resistance, we found that artificial inoculations of 48 butternut seedlings with O. clavigignenti-juglandacearum induced the expression of external symptoms, but only after a period of dormancy. Before dormancy, compartmentalized tissues such as necrophylactic periderms (NPs) and xylem reaction zones (RZs) contributed to limiting pathogen invasion. Phenols were regularly detected in RZs, often in continuity with NPs during wound closure, and confocal microscopy revealed their presence in parenchyma cells, vessel plugs and cell walls. Vessels were blocked with tyloses and gels, particularly those present in RZs. Suberin was also detected in cells formed over the affected xylem by the callus at the inoculation point, in a few tylosis walls, and in longitudinal tubes that formed near NPs. Following dormancy, in all inoculated seedlings but one, defensive barriers were breached by O. clavigignenti-juglandacearum and then additional ones were produced in response to this new invasion. The results of this histopathological study indicate that trees inoculated in selection programs to test butternut canker resistance should go through at least one period of dormancy and that asymptomatic individuals should be dissected to better assess how they defend themselves against O. clavigignenti-juglandacearum.

Antifungal Proteins from Plant Latex

2020 ◽  
Vol 21 (5) ◽  
pp. 497-506
Author(s):  
Mayck Silva Barbosa ◽  
Bruna da Silva Souza ◽  
Ana Clara Silva Sales ◽  
Jhoana D’arc Lopes de Sousa ◽  
Francisca Dayane Soares da Silva ◽  
...  
Keyword(s):  
Cell Walls ◽  
Defense Mechanisms ◽  
Hydrolytic Enzymes ◽  
Fungal Species ◽  
Biologically Active ◽  
Protein Classification ◽  
Fungal Cell ◽  
Antifungal Proteins ◽  
Plant Latex

Latex, a milky fluid found in several plants, is widely used for many purposes, and its proteins have been investigated by researchers. Many studies have shown that latex produced by some plant species is a natural source of biologically active compounds, and many of the hydrolytic enzymes are related to health benefits. Research on the characterization and industrial and pharmaceutical utility of latex has progressed in recent years. Latex proteins are associated with plants’ defense mechanisms, against attacks by fungi. In this respect, there are several biotechnological applications of antifungal proteins. Some findings reveal that antifungal proteins inhibit fungi by interrupting the synthesis of fungal cell walls or rupturing the membrane. Moreover, both phytopathogenic and clinical fungal strains are susceptible to latex proteins. The present review describes some important features of proteins isolated from plant latex which presented in vitro antifungal activities: protein classification, function, molecular weight, isoelectric point, as well as the fungal species that are inhibited by them. We also discuss their mechanisms of action.

scholarly journals Compatible and Incompatible Interactions in Wheat Involving the Bt-10 Gene for Resistance to Tilletia tritici, the Common Bunt Pathogen

2007 ◽  
Vol 97 (11) ◽  
pp. 1397-1405 ◽  
Author(s):  
Denis A. Gaudet ◽  
Zhen-Xiang Lu ◽  
Frances Leggett ◽  
Bryan Puchalski ◽  
André Laroche
Keyword(s):  
Compatible Interaction ◽  
Incompatible Interaction ◽  
Common Bunt ◽  
Tilletia Tritici ◽  
Pathogen Invasion ◽  
Reaction Zones ◽  
The Common ◽  
Wheat Lines ◽  
Compatible Interactions ◽  
Incompatible Interactions

The infection of wheat lines Neepawa (susceptible), and its sib BW553 that is nearly isogenic for the Bt-10 resistance gene by differentially virulent races T1 and T27 of common bunt (Tilletia tritici), was followed for 21 days following seeding (dfs) using fluorescence and confocal microscopy. Spore germination was nonsynchronous and all spore stages including germination were observed 5 to 21 dfs. Initial host perception of pathogen invasion, based on autofluorescence in epidermal cells adjacent to the appressoria, was similar in both compatible and incompatible interactions, and occurred as early as 5 to 6 dfs. The total number of sites on a 1-cm segment of coleoptile adjacent to the seed that exhibited autofluorescence was similar in both the compatible and incompatible interactions and rose to a maximum of 35 to 40 per 1 cm length of coleoptile following 17 dfs, although new infection events were observed as late as 21 dfs. In the compatible interaction, the autofluorescence became more diffuse 10 to 12 dfs, emanating in all directions in association with fungal spread. In the incompatible interaction, autofluorescence remained restricted to a small area surrounding the penetration site. Two different reaction zones that extended further in tissues surrounding the penetration point in the incompatible interaction compared with the compatible interaction were identified. The accumulation of callose around invading fungal hyphae was observed during both the compatible and incompatible interactions from 8 to 21 dfs. While callose accumulation was more extensive and widespread in the incompatible interaction, it was clearly present in compatible interactions, particularly in treatments involving BW553. These results were confirmed by expression of callose synthase transcripts that were more abundant in BW553 than in Neepawa and were upregulated during pathogen infection in both compatible and incompatible interactions.

scholarly journals Interaction between Bean and Colletotrichum gloeosporioides: Understanding Through a Biochemical Approach

Plants ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 345 ◽  
Author(s):  
Nilanjan Chakraborty ◽  
Kabita Mukherjee ◽  
Anik Sarkar ◽  
Krishnendu Acharya
Keyword(s):  
Reactive Oxygen Species ◽  
Defense Mechanisms ◽  
Colletotrichum Gloeosporioides ◽  
Developmental Stages ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Biochemical Basis ◽  
Pathogen Invasion ◽  
Defense Molecules ◽  
Bean Leaves

In addition to its role in animals, nowadays nitric oxide (NO) is considered as an emerging signaling molecule in plant systems. It is now believed that NO exerts its pivotal role in various plant physiological processes, such as in seed germination, plant developmental stages, and plant defense mechanisms. In this study, we have taken an initiative to show the biochemical basis of defense response activation in bean leaves during the progression of Colletotrichum gloeosporioides (Penz.) Penz. and Sacc. in detached bean leaves. Stages of pathogen penetration and colonization were successfully established in the detached bean leaves. Results showed up-regulation of different defense-related enzymes and other defense molecules, such as phenols, flavonoids, callose, and lignin molecules, along with NO at early stages of pathogen invasion. Although in the later stages of the disease, development of NO and other defense components (excluding lignin) were down-regulated, the production of reactive oxygen species in the form of H2O2 became elevated. Consequently, other stress markers, such as lipid peroxidation, proline content, and chlorophyll content, were changed accordingly. Correlation between the disease index and other defense molecules, along with NO, indicate that production of NO and reactive oxygen species (ROS) might influence the development of anthracnose in common bean.

scholarly journals Certain biochemical aspects of coronavirus infection COVID-19

2021 ◽  
Vol 86 (3) ◽  
pp. 17-22
Author(s):  
L. Kot ◽  
L.-A. Karpets ◽  
K. Sviridova ◽  
M. Chernikh ◽  
R. Prishlyak
Keyword(s):  
Defense Mechanisms ◽  
Clinical Manifestations ◽  
Target Cells ◽  
Global Public Health ◽  
Pathogen Invasion ◽  
Number Of Patients ◽  
Short Period ◽  
Threatening Condition ◽  
Important Challenge ◽  
Coronavirus Infection

An outbreak of coronavirus disease CoViD-19, caused by the new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), in a short period of time led to a global public health emergency worldwide. The difficult epidemiological situation associated with the rapid increase in the number of patients and the high mortality rate, as well as the need to overcome the consequences of the pandemic as soon as possible, have become an important challenge for science. The special attention of scientists is focused on in-depth study of the pathogenetic mechanisms of coronavirus infection, which is important for the development of antiviral drugs and vaccines to combat CoViD-19. To penetrate the target cells the virus uses receptors, expressed in various tissues of the organism, the main of which is angiotensin-converting enzyme 2 (ACE2). Virus replication is regulated by a lot of factors and causes abrupt morphological and physiological changes in cells. SARS-CoV-2 disrupts the regulation of inflammatory signaling pathways that generate a cytokine "storm", causes multisystem disorders and a life-threatening condition – acute respiratory distress syndrome. An important component of pathogenesis and clinical manifestations of CoViD-19 are hemostasis disorders, activation of thrombosis and thromboembolic complications. This review provides certain data regarding the structure of SARS-CoV-2, routes of infection, defense mechanisms against pathogen invasion, features of the hemostasis system in coronavirus infection, intracellular signal transduction, and current strategies for the prevention and treatment of CoViD-19, which are aimed primarily at suppressing the replication of the virus, limiting its dissemination and reducing the immune response of organism in conditions of infection.

scholarly journals Transcriptional profiling reveals conserved and species-specific plant defense responses during the interaction of the early divergent plant Physcomitrium patens with Botrytis cinerea

2020 ◽  
Author(s):  
Guillermo Reboledo ◽  
Astrid Agorio ◽  
Lucía Vignale ◽  
Ramón Alberto Batista-García ◽  
Inés Ponce De León
Keyword(s):  
Immune Response ◽  
Botrytis Cinerea ◽  
Defense Mechanisms ◽  
Molecular Mechanisms ◽  
Defense Responses ◽  
Land Plants ◽  
Differentially Expressed ◽  
Microbial Pathogens ◽  
Limited Information ◽  
Pathogen Invasion

AbstractBryophytes were among the first plants that colonized earth and they evolved key defense mechanisms to counteract microbial pathogens present in the new environment. Although great advances have been made on pathogen perception and subsequent defense activation in angiosperms, limited information is available in early divergent land plants. In this study, a transcriptomic approach uncovered the molecular mechanisms underlying the defense response of the bryophyte Physcomitrium patens against the important plant pathogen Botrytis cinerea. A total of 3.072 differentially expressed genes were significantly affected during B. cinerea infection, including genes encoding proteins with known function in angiosperm immunity and involved in pathogen perception, signaling, transcription, hormonal signaling, metabolic pathways such as shikimate and phenylpropanoid, and proteins with diverse role in defense against biotic stress. Similarly as in other plants, B. cinerea infection leads to downregulation of genes involved in photosynthesis and cell cycle progression. These results highlight the existence of evolutionary conserved defense responses to pathogens throughout the green plant lineage, suggesting that they were probably present in the common ancestors of land plants. Moreover, several genes acquired by horizontal transfer from prokaryotes and fungi, and a high number of P. patens-specific orphan genes were differentially expressed during B. cinerea infection, indicating that they are part of the moss immune response and probably played an ancestral role related to effective adaptation mechanisms to cope with pathogen invasion during the conquest of land.Key MessageEvolutionary conserved defense mechanisms present in extant bryophytes and angiosperms, as well as moss-specific defenses are part of the immune response of the early divergent land plant Physcomitrium patens.

scholarly journals Effect of Hevea brasiliensis latex sap gel on healing of acute skin wounds induced on the back of rats

2016 ◽  
Vol 43 (1) ◽  
pp. 48-53 ◽  
Author(s):  
Maria Vitória Carmo Penhavel ◽  
Victor Henrique Tavares ◽  
Fabiana Pirani Carneiro ◽  
João Batista de Sousa
Keyword(s):  
Wound Closure ◽  
Skin Flap ◽  
Muscle Layer ◽  
Control Group ◽  
Histopathological Study ◽  
Dorsal Skin ◽  
Experimental Conditions ◽  
Cutaneous Wounds ◽  
Study Results ◽  
Significant Difference

Objective : to evaluate the effect of topical delivery of latex cream-gel in acute cutaneous wounds induced on the back of rats. Methods : we subjected sixteen rats to dermo-epidermal excision of a round dorsal skin flap, with 2.5cm diameter. We divided the animals into two groups: Latex Group: application of cream-gel-based latex throughout the wound bed on postoperative days zero, three, six and nine; Control group: no treatment on the wound. Photographs of the lesions were taken on the procedure day and on the 6th and 14th postoperative days, for analyzing the area and the larger diameter of the wound. We carried out euthanasia of all animals on the 14th postoperative day, when we resected he dorsal skin and the underlying muscle layer supporting the wound for histopathological study. Results : there was no statistically significant difference in the percentage of wound closure, in the histopathological findings or in the reduction of the area and of the largest diameter of the wounds among the groups studied on the 14th postoperative day. Conclusion : according to the experimental conditions in which the study was conducted, latex cream-gel did not interfere in the healing of acute cutaneous wounds in rats.

Genetic diversity of butternut (Juglans cinerea) and implications for conservation

2008 ◽  
Vol 38 (4) ◽  
pp. 899-907 ◽  
Author(s):  
Amy Ross-Davis ◽  
Michael Ostry ◽  
Keith E. Woeste
Keyword(s):  
Genetic Diversity ◽  
Population Genetics ◽  
North America ◽  
Endangered Species ◽  
Isolation By Distance ◽  
Eastern North America ◽  
Native Range ◽  
Juglans Cinerea ◽  
Threatened And Endangered Species ◽  
Genetic Diversity And Structure

The management of threatened and endangered species can be improved by understanding their patterns of genetic diversity and structure. This paper presents the results of the first analysis of the population genetics of butternut ( Juglans cinerea L.) using nuclear microsatellites. Butternut once was an economically and ecologically valuable hardwood, but now its numbers are rapidly decreasing throughout its native range in eastern North America. By genotyping butternut trees (n = 157) from five populations at seven highly polymorphic loci, we determined that the remaining genetic diversity for the species is considerably higher than previously estimated (mean HE = 0.75). Populations were nearly genetically homogenous (FST = 0.025), with no evidence of isolation by distance. These results indicate that butternut retains a large amount of genetic diversity, and that it is not too late to implement strategies to conserve local butternut populations.

scholarly journals Apoplastic CBM1-interacting proteins bind conserved carbohydrate binding module 1 motifs in fungal hydrolases to counter pathogen invasion

2022 ◽  
Author(s):  
Takumi Takeda ◽  
Machiko Takahashi ◽  
Motoki Shimizu ◽  
Yu Sugihara ◽  
Hiromasa Saitoh ◽  
...  
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Fungal Pathogens ◽  
Carbohydrate Binding ◽  
Carbohydrate Binding Module ◽  
Cell Wall Degrading Enzymes ◽  
Fungal Enzymes ◽  
General Role ◽  
Pathogen Invasion ◽  
Wide Range

When infecting plants, fungal pathogens secrete cell wall degrading enzymes (CWDEs) that break down cellulose and hemicellulose, the primary components of plant cell walls. Some fungal CWDEs contain a unique domain, named the carbohydrate binding module (CBM), that facilitates their access to polysaccharides. However, little is known about how plants counteract pathogen degradation of their cell walls. Here, we show that the rice cysteine-rich repeat secretion protein OsCBMIP binds to and inhibits xylanase MoCel10A of the blast fungus pathogen Magnaporthe oryzae, interfering with its access to the rice cell wall and degradation of rice xylan. We found binding of OsCBMIP to various CBM1-containing enzymes, suggesting it has a general role in inhibiting the catalytic activities of fungal enzymes. OsCBMIP is localized to the apoplast, and its expression is strongly induced in leaves infected with M. oryzae. Remarkably, knockdown of OsCBMIP reduced rice defense against M. oryzae, demonstrating that inhibition of CBM1-containing fungal enzymes by OsCBMIP is crucial for rice defense. We also identified additional CBMIP-related proteins from Arabidopsis thaliana and Setaria italica, indicating that a wide range of plants counteract pathogens through this mechanism.

scholarly journals A phylogenetic and transcriptomic study of the β-1,3-glucanase family in tomato identifies candidate targets for fruit improvement

2021 ◽  
Author(s):  
Candelas Paniagua ◽  
Louisa Perry ◽  
Yoselin Benitez-Alfonso
Keyword(s):  
Cell Walls ◽  
Tomato Fruit ◽  
Fruit Softening ◽  
Pathogen Invasion ◽  
Qrt Pcr ◽  
Symplasmic Transport ◽  
And Function ◽  
The Impact ◽  
And Storage ◽  
Selection Of

Tomato, Solanum lycopersicum, is one of the most cultivated fruits. However, between one-quarter and half of their production is lost during transport and storage. Modifications in cell walls, and specifically pectin composition, delay fruit softening but, so far, the impact of callose metabolism in this process has not been investigated. Callose accumulates in cell walls around plasmodesmata to modify symplasmic transport. It also plays a role in reinforcing cell walls in response to bruising or pathogen invasion. The aim of this work is to identify cell wall β-1,3-glucanases expressed in tomato fruit that can be used as targets to modify callose accumulation during ripening. A phylogenetic analysis identified fifty candidate β-1,3-glucanases in tomato distributed in three clusters (α, β and γ) with evolutionary relations previously characterised in the model Arabidopsis thaliana. Analysis of tomato microarray data indicates different regulatory patterns: the expression of a subset of enzymes in cluster α decreased during ripening, while enzymes in cluster β and γ displayed higher expression in white-red stages. qRT-PCR experiments confirm the differential regulation of enzymes in different clusters suggesting evolutionary divergences that correlate with differences in their predicted localization and function. The potential to exploit this information in the selection of targets to modify cell walls and fruit development is discussed.

scholarly journals 026 MICROPROPAGATION OF BUTTERNUT, JUGLANS CINEREA

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 431c-431 ◽  
Author(s):  
Paula M. Pijut
Keyword(s):  
Germ Plasm ◽  
Casein Hydrolysate ◽  
Ms Medium ◽  
Native Range ◽  
Juglans Cinerea ◽  
Canker Pathogen ◽  
Disease Resistant ◽  
Single Shoot ◽  
Half Strength

Butternut (Juglans cinerea L.), a native hardwood to the northeastern United States, is a valuable species for its wood and edible nuts. Butternut is becoming endangered in its native range as a result of a virulent fungal (perennial canker) pathogen, Sirococcus clavigignenti - juglandacearum. Micropropagation techniques are being developed to clone disease-resistant specimens. Axillary buds, obtained from 2-3-month old seedlings, were induced to break buds in vitro and form a single shoot when cultured on Murashige and Skoog (MS) medium supplemented with 200 mg/l casein hydrolysate, 3% sucrose, and 2 mg/l 6-benzylaminopurine. Roots were initiated on microshoots when cultured on half-strength MS medium containing 100 mg/l casein hydrolysate, 1.5% sucrose, and 0.5 mg/l indole-3-butyric acid for seven days in the dark. Adventitious roots elongated when shoots were placed in the light on the same medium, but with 2% sucrose, and no growth regulators. Rooted plantlets were successfully acclimated ex vitro. These results provide a basis for the development of techniques to micropropagate selected, mature, disease-resistant butternut germ plasm.

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