ACTIVIDAD ENZIMÁTICA Y PROCESO DE INFECCIÓN INICIAL DE LA PLANTA DE GUARANÁ (Paullinia cupana) POR CEPAS PATOGÉNICAS Y ENDOFÍTICAS DE Colletotrichum guaranicola

2021 ◽  
Vol 44 (1) ◽  
pp. 67
Author(s):  
Marcely Andrade da Silva ◽  
Cledir Santos ◽  
Francisco Pérez-Nevado ◽  
Nelson Lima ◽  
Jânia Lilia Da Silva-Bentes
Keyword(s):  
Experimental Design ◽  
Enzyme Reaction ◽  
Infection Process ◽  
Fungal Strain ◽  
Enzymatic Activities ◽  
Plant Tissues ◽  
Disease Symptoms ◽  
Initial Infection ◽  
Paullinia Cupana ◽  
Appressoria Formation

Anthracnose of the guarana plant (Paullinia cupana) is a disease caused by Colletotrichum guaranicola Albuq. Few studies have analyzed the origin, the form of penetration and the colonization of endophytic fungi in the guarana plant. This study aimed to determine differences in the enzymatic activities of endophytic and pathogenic strains of C. guaranicola during the initial infection process in leaves of clones sensitive to guarana anthracnose. Fourteen pathogenic and nine endophytic strains of C. guaranicola were isolated from guarana leaves with and without anthracnose symptoms, respectively. The enzymatic activities of protease, amylase, polyphenol oxidase, lipase, pectinase, and cellulolytic activities were evaluated for each fungal strain. The experimental design for each enzymatic assay was completely randomized with five replicates. The enzymatic evaluation was based on the measurement of halo produced by the enzyme reaction in each assay. Conidia were evaluated during germination and appressoria formation. Results did not detect enzymatic difference between pathogenic and endophytic strains. Data prior to germination showed differences between endophytic and pathogenic strains. Colonization of plant tissues by pathogenic strain was evidenced after the appearance of disease symptoms 48 hours after inoculation (hai), while for endophytic strains the presence of appressoria was observed on the surface of the epidermis 48 hai, and colonization of cells was not observed.

The current state of mycotoxin biomarker development in humans and animals and the potential for application to plant systems

2011 ◽  
Vol 4 (3) ◽  
pp. 257-270 ◽  
Author(s):  
T. Baldwin ◽  
R. Riley ◽  
N. Zitomer ◽  
K. Voss ◽  
R. Coulombe Jr. ◽  
...  
Keyword(s):  
Disease Risk ◽  
Biological Effects ◽  
Fusarium Verticillioides ◽  
Laboratory Animals ◽  
Plant Tissues ◽  
Living Plant ◽  
Disease Symptoms ◽  
Mechanisms Of Toxicity ◽  
Livestock Feeds ◽  
Commercially Important

Filamentous fungi that contaminate livestock feeds and human food supply often produce toxigenic secondary metabolites known as mycotoxins. Among the hundreds of known mycotoxins, aflatoxins, deoxynivalenol, fumonisins, ochratoxin A and zearalenone are considered the most commercially important. Intense research on these mycotoxins, especially aflatoxin, has resulted in the development of 'biomarkers' used to link exposure to disease risk. In the case of aflatoxin this effort has led to the discovery of both exposure and mechanism-based biomarkers, which have proven essential for understanding aflatoxin's potential for causing disease in humans, including subtle effects on growth and immune response. Fumonisin biomarkers have also been used extensively in farm and laboratory animals to study the fumonisin-induced disruption of cellular and systemic physiology which leads to disease. This review summarises the status of mycotoxin biomarker development in humans and animals for the commercially important mycotoxins. Since the fungi responsible for the production of these mycotoxins are often endophytes that infect and colonise living plant tissues, accumulation of mycotoxins in the plant tissues may at times be associated with development of plant disease symptoms. The presence of mycotoxins, even in the absence of disease symptoms, may still have subtle biological effects on the physiology of plants. This review examines the question of whether or not the knowledge gained from mechanistic studies and development of biomarkers in animal and human systems is transferable to the study of mycotoxin effects on plant systems. Thus far, fumonisin has proven amenable to development of mechanism-based biomarkers to study maize seedling disease caused by the fumonisin producer, Fusarium verticillioides. Expanding our knowledge of mechanisms of toxicity and the overt and subtle effects on animal, human, and plant systems through the identification and validation of biomarkers will further our ability to monitor and limit the damage and economic impact of mycotoxins.

scholarly journals Host-Specific Activation of Entomopathogenic Nematode Infective Juveniles

Insects ◽  
2018 ◽  
Vol 9 (2) ◽  
pp. 59 ◽  
Author(s):  
Valentina Alonso ◽  
Shyon Nasrolahi ◽  
Adler Dillman
Keyword(s):  
Entomopathogenic Nematodes ◽  
Morphological Changes ◽  
Entomopathogenic Nematode ◽  
Infection Process ◽  
Bacterial Symbiont ◽  
Infective Juvenile ◽  
Free Living ◽  
Initial Infection ◽  
Host Tissues ◽  
Insect Parasites

Entomopathogenic nematodes (EPNs) are potent insect parasites and have been used for pest control in agriculture. Despite the complexity of the EPN infection process, hosts are typically killed within 5 days of initial infection. When free-living infective juveniles (IJs) infect a host, they release their bacterial symbiont, secrete toxic products, and undergo notable morphological changes. Collectively, this process is referred to as “activation” and represents the point in a nematode’s life cycle when it becomes actively parasitic. The effect of different host tissues and IJ age on activation, and how activation itself is related to virulence, are not well understood. Here, we employed a recently developed bioassay, which quantifies IJ activation, as a tool to address these matters. Appreciating that activation is a key part of the EPN infection process, we hypothesized that activation would positively correlate to virulence. Using the EPNs Steinernema carpocapsae and S. feltiae we found that EPN activation is host-specific and influenced by infective juvenile age. Additionally, our data suggest that activation has a context-dependent influence on virulence and could be predictive of virulence in some cases such as when IJ activation is especially low.

scholarly journals Mycotoxins Biosynthesized by Plant-Derived Fusarium Isolates / Tvorba Mikotoksina U Vrstama Roda Fusarium Izoliranim Iz Biljaka

2012 ◽  
Vol 63 (4) ◽  
pp. 437-446 ◽  
Author(s):  
Agnieszka Waśkiewicz ◽  
Łukasz Stępień
Keyword(s):  
Secondary Metabolites ◽  
Asymptomatic Infection ◽  
Crop Plants ◽  
High Mass ◽  
Plant Tissues ◽  
Disease Symptoms ◽  
Perennial Crops ◽  
Mass Fractions ◽  
Very High

AbstractThere is little information on secondary metabolites produced by Fusaria infecting crop plants other than cereals. Many members of Fusarium genus have the ability to colonise perennial crops with only scarce infection or disease symptoms or with no symptoms at all while still being detectable. Even in case of such asymptomatic infection, significant mycotoxin contamination of the plant tissues is possible. The aim of this study was to characterise the spectrum of Fusarium species isolates obtained from different plant hosts (like asparagus, garlic, pineapple, banana, rhubarb, peppers, rice, maize, wheat, and oncidium) and evaluate their ability to biosynthesize the most common mycotoxins in vitro. Among the F.proliferatum isolates, up to 57 % of them biosynthesized fumonisins at very high mass fractions, amounting to above 1000 μg g-1, while other Fusarium species such as F. verticillioides, F. lactis, F. polyphialydicum, F. concentricum, F. temperatum, and F. fujikuroi formed fumonisins mostly at much lower level. Only F.ananatum and F. oxysporum did not produce these toxins. Co-occurrence of FBs with other mycotoxins [moniliformin (MON) and beauvericin (BEA)] was often observed and it was mainly F. proliferatum species that formed both mycotoxins (0.4 μg g-1 to 41.1 μg g-1 BEA and 0.1 μg g-1 to 158.5 μg g-1 MON).

scholarly journals Using Leaf Temperature as a Nondestructive Procedure to Detect Root Rot Stress in Geranium

2007 ◽  
Vol 17 (4) ◽  
pp. 532-536 ◽  
Author(s):  
Medani Omer ◽  
James C. Locke ◽  
Jonathan M. Frantz
Keyword(s):  
Root Rot ◽  
Infection Process ◽  
Leaf Temperature ◽  
Aesthetic Value ◽  
Greenhouse Production ◽  
Soil Pathogens ◽  
Disease Symptoms ◽  
Visual Symptoms ◽  
Growing Conditions ◽  
The Aesthetic

Diagnosis of incipient disease based on visual symptoms of geraniums (Pelargonium ×hortorum) exposed to water mold pathogens is often difficult, especially when the plants are maintained under optimum growing conditions. Such plants tend to be asymptomatic until late in the infection process when control methods are less effective and the aesthetic value of the finished crop is diminished. To circumvent such a problem and to be able to predict the susceptibility of the plants to infection, we used infrared transducers to measure leaf surface temperature, in addition to other parameters, in geranium plants exposed to a number of soil pathogens that are commonly associated with greenhouse production. Differences in leaf temperature among treatments were noticeable by 2 week after inoculation and were the greatest in week 7. However, visual disease symptoms were not detected until 3 weeks after inoculation. Results of this study suggest that leaf temperature measurements are a versatile, nondestructive way of rapidly determining whether plants are under pathogen stress before visual symptoms develop.

scholarly journals Molecular Characterization of the NADPH Oxidase Complex in the Ergot Fungus Claviceps purpurea: CpNox2 and CpPls1 Are Important for a Balanced Host-Pathogen Interaction

2013 ◽  
Vol 26 (10) ◽  
pp. 1151-1164 ◽  
Author(s):  
Janine Schürmann ◽  
Dagmar Buttermann ◽  
Andrea Herrmann ◽  
Sabine Giesbert ◽  
Paul Tudzynski
Keyword(s):  
Nadph Oxidase ◽  
Pathogenic Fungi ◽  
Infection Process ◽  
Regulatory Subunit ◽  
Claviceps Purpurea ◽  
Oxygen Species ◽  
Disease Symptoms ◽  
Host Pathogen Interaction ◽  
Nadph Oxidase Complex

Reactive oxygen species producing NADPH oxidase (Nox) complexes are involved in defense reactions in animals and plants while they trigger infection-related processes in pathogenic fungi. Knowledge about the composition and localization of these complexes in fungi is limited; potential components identified thus far include two to three catalytical subunits, a regulatory subunit (NoxR), the GTPase Rac, the scaffold protein Bem1, and a tetraspanin-like membrane protein (Pls1). We showed that, in the biotrophic grass-pathogen Claviceps purpurea, the catalytical subunit CpNox1 is important for infection. Here, we present identification of major Nox complex partners and a functional analysis of CpNox2 and the tetraspanin CpPls1. We show that, as in other fungi, Nox complexes are important for formation of sclerotia; CpRac is, indeed, a complex partner because it interacts with CpNoxR, and CpNox1/2 and CpPls1 are associated with the endoplasmatic reticulum. However, unlike in all other fungi, Δcppls1 is more similar to Δcpnox1 than to Δcpnox2, and CpNox2 is not essential for infection. In contrast, Δcpnox2 shows even more pronounced disease symptoms, indicating that Cpnox2 controls the infection process and moderates damage to the host. These data confirm that fungal Nox complexes have acquired specific functions dependent of the lifestyle of the pathogen.

Application of 2III7−3fractional factorial experimental design to enhance enzymatic activities ofPleurotus ostreatuswith high concentrations of polychlorinated biphenyls

2011 ◽  
Vol 46 (3) ◽  
pp. 298-305 ◽  
Author(s):  
Martha Gayosso-Canales ◽  
Fernando J. Esparza-García ◽  
Rosa M. Bermúdez-Cruz ◽  
Araceli Tomasini ◽  
Graciela M.L. Ruiz-Aguilar ◽  
...  
Keyword(s):  
Experimental Design ◽  
Polychlorinated Biphenyls ◽  
Enzymatic Activities ◽  
Factorial Experimental Design ◽  
High Concentrations

scholarly journals Estudio de insecticidas para el control de mosca blanca Bemisia tabaci Genn enn el cultivo del frijol Phaseolus vulgaris L.

2016 ◽  
Vol 3 ◽  
pp. 57
Author(s):  
José E. Mancía ◽  
José C. Escobar ◽  
Adán Hernández ◽  
Julio Soto ◽  
Santos P. Bonilla
Keyword(s):  
Experimental Design ◽  
Phaseolus Vulgaris ◽  
Bemisia Tabaci ◽  
Susceptible Variety ◽  
Phaseolus Vulgaris L ◽  
Net Benefit ◽  
Disease Symptoms ◽  
The Third ◽  
Experimental Station ◽  
San Andres

Several trials were conducted to evaluate the effectiveness of new insecticides in controlling the white fly Bemisia tabaci Genn, which is the vector of the Bean Golden Mosaic Virus (BGMV), at the Zapotitlan Valley and at the San Andres Experimental Station at 460 masl, during the dry season, from December 22, 1989 to May, 1990. A complete randomized block experimental design with 4 and 5 replications was used. Four trials were planted with the Rojo de Seda, Sangre de Toro and CENIA-Cuscatleco bean varieties. In the first and second trials, the chemicals bifentrin 100 EC (60 g.ai./ha) and fenpropatrin 375 EC ( 203 g.ai/ha) were efficient in controlling the whitefly, reducing the incidence of BGMV. If B. tabaci Genn is not controlled efficiently and timely, the BGMV incidence reaches 100% between 36 and 32 days after planting (DAP) on the susceptible varieties Rojo de Seda y Sangre de Toro. Seed and soil treatments combined with foliage spraying were also used in the third and fourth trials. The treatments of carbosulpan + bifentrin (1519.9 kg/ha) and acephate + bifentrin (1428 kg/ha) produced the highest yields with the resistent variety CENIA- Cuscatleco. Acephate + fenpropatrin (756.6 kg/ha), acephate + bifentrin (725.1 kg/ha) and carbofuran + fenpropatrin (636.3 g/ha) produced the highest yields with the susceptible variety Rojo de Seda. Of the tested products, fenpropatrin 375 EC showed the lowest populations of eggs and nymphs of B. tabaci Genn. There was a significant correlation between production and the time when the disease symptoms appeared. The largest Net Benefit was obtained with acephate 95% + bifentrin 100 EC treatment, followed by carbofuran 5% + bifentrin 100 EC.

Olfactory Attraction of Rhizome Borer (Coleoptera: Curculionidae) to Banana Genotypes Inoculated with Entomopathogenic Fungus

2019 ◽  
pp. 1-6
Author(s):  
Angélica Da Silva Salustino ◽  
Ivan Sérgio Da Silva Oliveira ◽  
Marailze Pereira dos Santos ◽  
Ana Paula Pereira do Nascimento ◽  
Marcos Barros de Medeiros
Keyword(s):  
Experimental Design ◽  
Beauveria Bassiana ◽  
Cosmopolites Sordidus ◽  
Plant Tissues ◽  
Olfactory Responses ◽  
Agriculture Sector ◽  
Two Stages ◽  
Fungus Beauveria Bassiana ◽  
Insect Attack ◽  
Banana Plantation

The species: Cosmopolites sordidus (Germar) (Coleoptera: Curculionidae) stands out as one of the main pests of banana. The damage to the crop is caused by the larvae of this pest, when they feed on the plant tissues. The aim of this study was to investigate the olfactory responses of C. sordidus for different varieties and the possible olfactory interference after application of Beauveria bassiana fungus on the crop. The research was conducted at the Phytosanitary Clinic in the Agriculture Sector of the Center for Humanities, Social and Agrarian Sciences of the Federal University of Paraíba, located in Bananeiras - PB, Brazil, from January to July 2017. The experimental design was completely randomized, with four treatments represented by banana varieties (Apple, Silver, Nanica and Pacovan) with 11 replications each. The bioassays were distributed in two stages; the first stage was an evaluation of the attractiveness of banana genotypes and rhizome and pseudostem tissues. In the second, the attractiveness of C. sordidus to the tissues contaminated with the fungus B. bassiana was investigated. The Prata banana plantation was less attractive to C. sordidus, the highest preference was to the Nanica banana plantation. The most attractive tissue was pseudostem. Given the conditions under which the study was conducted, the banana plantation and the plant tissues analyzed present an olfactory influence under Cosmopolites sordidus. The Nanica banana plantation is the most susceptible to insect attack. The application of the fungus Beauveria bassiana on banana baits does not interfere with the odour conditions exerted the nanica banana plantation under C. sordidus.

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