scholarly journals Fungal growth is affected by and affects pH and redox potential (Eh) of the growth medium

2018 ◽  
Author(s):  
L. Bousset ◽  
M. Ermel ◽  
B. Soglonou ◽  
O. Husson
Keyword(s):  
Host Plants ◽  
Plant Pathogens ◽  
Infected Plant ◽  
Control Plant ◽  
Fungal Growth ◽  
Plant Diseases ◽  
Fungal Plant Pathogens ◽  
Agar Media ◽  
The Impact

AbstractFungal plant pathogens live in the specific environment of plants. Understanding of the interaction between pathogens and their host plants might open new ways to control plant diseases. Yet, the specificities of the plant environment and its effects on fungal growth are not yet fully explored. Both pH and Eh play a key role during the interaction between the fungus and its host plants, but often studied independently or at different scales. To decipher the interrelation between plant growth and their soil environment, recent theoretical and methodological advances have been made through the joint characterization of the pH and Eh. This opens the prospect to develop similar methods for fungi. The aim of our study was to investigate whether the methods developed for soil could be transposed to fungi. We first worked on artificial media, assessing the impact of fungal growth on the media in cultures. The growth of all 16 species tested significantly altered either Eh, pH or both in agar media. Measuring Eh reveals that even the species not modifying pH can have an impact on the surrounding environment. Reciprocally, altered media were used to characterize sensitivity of fungal growth to both pH and Eh parameters. The response of the six fungi tested to the modified media was quantitative with a decrease in colony diameter. In addition, colony aspect was repeatedly and thoroughly modified. As a first step towards the same studies in conditions matching the natural environment of fungal pathogens, we tested how the measurement can be performed with fungi growing on oilseed rape plants. In infected plant stems, pH and Eh were significantly altered, in opposite directions for L. maculans and S. sclerotiorum. The observed alcalinisation or acidification correlates with canker length. Our series of experiments indicate that the procedure published for Eh and pH in soil can be extended for measurement in agar media and in infected plants. Further, the joint characterization of both parameters opens the way to a more precise understanding of the impact of fungi on their environment, and conversely, of the environment on fungal growth. The availability of methods for measurement opens the prospect to study combinations of stresses, either on agar media or in plants, and get an understanding of the involvement of pH and Eh modifications in these interactions.

Advances in screening approaches for the development of microbial bioprotectants to control plant diseases

2021 ◽  
pp. 33-86
Author(s):  
Wagner Bettiol ◽  
◽  
Flávio Henrique Vasconcelos de Medeiros ◽  
Josiane Barros Chiaramonte ◽  
Rodrigo Mendes ◽  
...  
Keyword(s):  
Plant Pathogens ◽  
Plant Protection ◽  
Control Plant ◽  
Control Programme ◽  
Plant Diseases ◽  
Advantages And Disadvantages ◽  
Fungal Plant Pathogens ◽  
Soil Rhizosphere ◽  
Selection Of ◽  
Screening Approaches

The success of a biological control programme depends on the isolation and selection of antagonists. There is an enormous diversity of culturable microbial species in the soil, rhizosphere, phylloplane, spermosphere and carposphere, which can be used in the isolation and selection of antagonists. The structures of fungal plant pathogens concerned with survival and infection may also be sources of antagonists. Although non-culturable microorganisms and microbiome-based strategies have great potential for development as commercial products in disease control, more knowledge is needed to understand the mechanisms involved in interactions between plants and complex microbial communities. Methods of isolation and selection of the most commercially exploited groups of antagonists and their advantages and disadvantages are discussed in this chapter as well as those of non-traditional antagonists. Finally, possible strategies for engineering the soil and host microbiome to actively promote plant protection against pathogens are discussed.

scholarly journals Microbiomes and Pathogen Survival in Crop Residues, an Ecotone Between Plant and Soil

2019 ◽  
Vol 3 (4) ◽  
pp. 246-255 ◽  
Author(s):  
Lydie Kerdraon ◽  
Valérie Laval ◽  
Frédéric Suffert
Keyword(s):  
Disease Management ◽  
Microbial Communities ◽  
Plant Pathogens ◽  
Crop Residues ◽  
Abiotic Factors ◽  
Plant Diseases ◽  
Negative Contribution ◽  
Positive Effects ◽  
Fungal Plant Pathogens ◽  
The Impact

The negative contribution of crop residues as a source of inoculum for plant diseases is well established. However, microbial ecologists have long reported positive effects of residues on the stability of agrosystems and conservation tillage practices have become increasingly widespread. Most studies have suggested that large microbial communities should be taken into account in plant disease management, but we know little about their ecological interaction with pathogens in the crop residue compartment. This review focuses on microbiomes associated with residues within the context of other microbial habitats in cereal-producing agroecosystems such as phyllosphere or rhizosphere. We connected residue microbiome with the survival of residue-borne fungal plant pathogens, thus combining knowledge in microbial ecology and epidemiology, two disciplines still not sufficiently connected. We provide an overview of the impact of residues on cereal disease epidemics and how dynamic interactions between microbial communities of nonburied residues during their degradation, along with soil and multitude of abiotic factors, can contribute to innovative disease management strategies, including next-generation microbiome-based biocontrol strategies. Starting from the classical but still relevant view of crop residues as a source of pathogen inoculum, we first consider possibilities for limiting the amount of residues on the soil surface to reduce the pathogen pressure. We then describe residues as a transient half-plant/half-soil compartment constituting a key fully fledged microbial ecosystem: in other words, an ecotone which deserves special attention. We focus on microbial communities, the changes in these communities over time and the factors influencing them. Finally, we discuss how the interactions between the microbial communities and the pathogens present on residues could be used: identification of keystone taxa and beneficial assemblages, then preservation of these taxa by adapted agronomic practices or development of synthetic communities, rather than the introduction of a single exogenous biocontrol species designed as a treatment product. [Formula: see text] Copyright © 2019 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

scholarly journals Fusarium: a ubiquitous fungus of global significance

2012 ◽  
Vol 33 (1) ◽  
pp. 22 ◽  
Author(s):  
LW Burgess ◽  
WL Bryden
Keyword(s):  
Plant Pathogens ◽  
Disease Incidence ◽  
Farming Systems ◽  
Plant Diseases ◽  
Natural Ecosystems ◽  
Fungal Plant Pathogens ◽  
Wide Range ◽  
Socio Economic Impact ◽  
Key Aspects ◽  
The Impact

Fusarium is one of the most economically important genera of fungal plant pathogens, causing significant crop losses and contamination of grain by mycotoxins on a global basis. Some species also cause infections (mycoses) of humans and other animals. Fusarium includes many species, a significant number of which cause a wide range of plant diseases that affect many crops including major food and fibre crops such as wheat, barley, maize, bananas and cotton, often with devastating socio-economic impact. The diseases are often insidious and extremely difficult to control. Its success as a plant pathogen can be attributed to wide host ranges, endophytic infection, and varied modes of survival and dispersal. Representatives occur in virtually all bioclimatic regions of the world in agricultural and natural ecosystems. In this article we present a summary of the key aspects of the biology and morphology of Fusarium and then briefly discuss several plant diseases to illustrate the diverse nature and devastating effects of these fungi, their mycotoxins, the impact of no-till farming systems on disease incidence, and the poorly understood but key role of endophytic colonisation in the disease cycle. Inevitably, the coverage is selective but it indicates the potential global impact of this fungal genus on plant disease and food security.

scholarly journals Sensoriamento remoto como ferramenta aos estudos de doenças de plantas agrícolas: uma revisão (Remote Sensing as a Toll for the Study of Plant Diseases on Agriculture: a Revision)

2011 ◽  
Vol 3 (3) ◽  
pp. 190 ◽  
Author(s):  
Carine Rosa Naue ◽  
Marilia W. Marques ◽  
Nelson Bernardi Lima ◽  
Josiclêda Domiciano Galvíncio
Keyword(s):  
Remote Sensing ◽  
Plant Pathogens ◽  
Infected Plant ◽  
Control Plant ◽  
Direct Methods ◽  
Epidemiological Studies ◽  
Plant Diseases ◽  
Indirect Methods ◽  
Multispectral Remote Sensing ◽  
Remote Sensing Techniques

Para que estudos epidemiológicos e medidas de controle de doenças de plantas fossem realizados foi necessário o desenvolvimento de métodos de quantificação de doenças. As doenças podem ser avaliadas por métodos diretos ou indiretos e dentre os métodos diretos encontram-se a estimativa dos parâmetros de incidência e severidade e as técnicas de sensoriamento remoto. Em estudos de doenças de plantas, o sensoriamento remoto, além de ser utilizado para quantificação, também poderá servir para a detecção de plantas infectadas. A detecção de doenças de plantas ou até mesmo sua quantificação, através do sensoriamento remoto, baseia-se na radiação refletida das folhagens. As diferenças de reflectância podem ser obtidas pelo sensoriamento remoto multispectral, que tem sido utilizado de forma eficiente para controlar a incidência de um número de patógenos de plantas e atualmente por medidas hiperespectrais. O objetivo deste artigo é apresentar uma revisão sobre o uso do sensoriamento remoto na detecção e análise de doenças de plantas. Os estudos apresentados aqui mostram que o sensoriamento remoto é uma ferramenta que pode ser utilizada para detectar plantas doentes de forma rápida e eficiente em pequenas e grandes áreas geográficas. Além disso, pode detectar plantas infectadas, dispensar a coleta e o processamento de amostras em laboratório permitindo levantamentos precisos e confiáveis, em curto espaço de tempo, independente do tamanho da área em questão. Além disso, pode proporcionar diversos estudos na área de fitopatologia e afins.Palavras-chave: Sensoriamento remoto, doenças de plantas, hiperespectral Remote Sensing as a Toll for the Study of Plant Diseases on Agriculture: a Revision  ABSTRACT For epidemiological studies and measures to control plant diseases were carried out was necessary to develop methods of quantifying disease. The diseases can be assessed by direct or indirect methods and among the direct methods are estimating the incidence and severity parameters and remote sensing techniques. In studies of plant diseases, remote sensing is used to quantify, can also serve for detection of infected plants. The detection of plant diseases or even to quantify, through remote sensing, based on reflected radiation from foliage. The differences in reflectance can be obtained by multispectral remote sensing, which has been used effectively to control incidence a number of plant pathogens and recently, hyperspectral measurements. The aim of this paper is present a review on use of remote sensing in detection and analysis of plant diseases. The studies presented here show that remote sensing is a tool that can be used to detect diseased plants quickly and efficiently in large and small geographic areas. Moreover, it can detect infected plant, waive the collection and processing of lab samples allowing accurate and reliable surveys in a short space of time, regardless of size of the area. In addition, several studies can provide in the area of plant pathology and related areas. Key-words: remote sensing, diseased plants, hyperspectral.

scholarly journals The carbon source-dependent pattern of antimicrobial activity and gene expression in Pseudomonas donghuensis P482

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Marta Matuszewska ◽  
Tomasz Maciąg ◽  
Magdalena Rajewska ◽  
Aldona Wierzbicka ◽  
Sylwia Jafra
Keyword(s):  
Gene Expression ◽  
Antimicrobial Activity ◽  
Carbon Source ◽  
Reference Genes ◽  
Plant Pathogens ◽  
Plant Protection ◽  
Carbon Sources ◽  
Unknown Compound ◽  
Fungal Plant Pathogens ◽  
The Impact

AbstractPseudomonas donghuensis P482 is a tomato rhizosphere isolate with the ability to inhibit growth of bacterial and fungal plant pathogens. Herein, we analysed the impact of the carbon source on the antibacterial activity of P482 and expression of the selected genes of three genomic regions in the P482 genome. These regions are involved in the synthesis of pyoverdine, 7-hydroxytropolone (7-HT) and an unknown compound (“cluster 17”) and are responsible for the antimicrobial activity of P482. We showed that the P482 mutants, defective in these regions, show variations and contrasting patterns of growth inhibition of the target pathogen under given nutritional conditions (with glucose or glycerol as a carbon source). We also selected and validated the reference genes for gene expression studies in P. donghuensis P482. Amongst ten candidate genes, we found gyrB, rpoD and mrdA the most stably expressed. Using selected reference genes in RT-qPCR, we assessed the expression of the genes of interest under minimal medium conditions with glucose or glycerol as carbon sources. Glycerol was shown to negatively affect the expression of genes necessary for 7-HT synthesis. The significance of this finding in the light of the role of nutrient (carbon) availability in biological plant protection is discussed.

scholarly journals Preliminary Study on the Activity of Phycobiliproteins against Botrytis cinerea

Marine Drugs ◽  
2020 ◽  
Vol 18 (12) ◽  
pp. 600
Author(s):  
Hillary Righini ◽  
Ornella Francioso ◽  
Michele Di Foggia ◽  
Antera Martel Quintana ◽  
Roberta Roberti
Keyword(s):  
Spore Germination ◽  
Plant Pathogens ◽  
Disease Incidence ◽  
Fungal Growth ◽  
Pathogenic Fungi ◽  
Gray Mold ◽  
Fungal Plant Pathogens ◽  
Ft Ir ◽  
Preliminary Study ◽  
Ft Raman

Phycobiliproteins (PBPs) are proteins of cyanobacteria and some algae such as rhodophytes. They have antimicrobial, antiviral, antitumor, antioxidative, and anti-inflammatory activity at the human level, but there is a lack of knowledge on their antifungal activity against plant pathogens. We studied the activity of PBPs extracted from Arthrospiraplatensis and Hydropuntiacornea against Botrytiscinerea, one of the most important worldwide plant-pathogenic fungi. PBPs were characterized by using FT-IR and FT-Raman in order to investigate their structures. Their spectra differed in the relative composition in the amide bands, which were particularly strong in A. platensis. PBP activity was tested on tomato fruits against gray mold disease, fungal growth, and spore germination at different concentrations (0.3, 0.6, 1.2, 2.4, and 4.8 mg/mL). Both PBPs reduced fruit gray mold disease. A linear dose–response relationship was observed for both PBPs against disease incidence and H. cornea against disease severity. Pathogen mycelial growth and spore germination were reduced significantly by both PBPs. In conclusion, PBPs have the potential for being also considered as natural compounds for the control of fungal plant pathogens in sustainable agriculture.

Localization and Visualization of Specific Gene Products in Fungal Plant Pathogens

2000 ◽  
Vol 6 (S2) ◽  
pp. 680-681 ◽  
Author(s):  
T. M. Bourett ◽  
K. J. Czymmek ◽  
T. M. Dezwaan ◽  
J. A. Sweigard ◽  
R. J. Howard
Keyword(s):  
Fungal Pathogens ◽  
Plant Pathogens ◽  
Protein Localization ◽  
Infected Plant ◽  
Cell Interaction ◽  
Specific Gene ◽  
Gene Products ◽  
Tem Analysis ◽  
Fungal Plant Pathogens ◽  
Plant Pathogenesis

Specific gene products of both pathogens and hosts have been implicated as decisive elements during plant pathogenesis. While expression of some of these genes is constitutive, that of others is likely ephemeral and activated only during a particular stage of the interaction. Because the relative timing of expression may be critical, transcription and translation have often been addressed by extracting mRNA and proteins from infected plant tissue. This approach, however, cannot readily detect proteins of low abundance in bulk samples nor offer much useful information on cell-cell interaction. Only a cytological analysis that employs microscopy can resolve the temporal and spatial details of gene expression. Typically, such protein localization studies have required specific antibodies, but these large probe molecules do not diffuse into living or conventionally fixed cells of either fungal pathogens or plant hosts. For TEM analysis, these permeability-imposed limitations have been reduced by thin sectioning to render accessible antibody binding sites.

scholarly journals Fungal Pathogens Affecting the Production and Quality of Medical Cannabis in Israel

Plants ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 882
Author(s):  
Shachar Jerushalmi ◽  
Marcel Maymon ◽  
Aviv Dombrovsky ◽  
Stanley Freeman
Keyword(s):  
Fungal Pathogens ◽  
Plant Pathogens ◽  
Pathogenic Fungi ◽  
Plant Diseases ◽  
Soilborne Pathogens ◽  
Medical Cannabis ◽  
Plant Parts ◽  
Commercial Cultivation

The use of and research on medical cannabis (MC) is becoming more common, yet there are still many challenges regarding plant diseases of this crop. For example, there is a lack of formal and professional knowledge regarding fungi that infect MC plants, and practical and effective methods for managing the casual agents of disease are limited. The purpose of this study was to identify foliar, stem, and soilborne pathogens affecting MC under commercial cultivation in Israel. The predominant major foliage pathogens were identified as Alternaria alternata and Botrytis cinerea, while the common stem and soilborne pathogens were identified as Fusarium oxysporum and F. solani. Other important fungi that were isolated from foliage were those producing various mycotoxins that can directly harm patients, such as Aspergillus spp. and Penicillium spp. The sampling and characterization of potential pathogenic fungi were conducted from infected MC plant parts that exhibited various disease symptoms. Koch postulates were conducted by inoculating healthy MC tissues and intact plants with fungi isolated from infected commercially cultivated symptomatic plants. In this study, we report on the major and most common plant pathogens of MC found in Israel, and determine the seasonal outbreak of each fungus.

scholarly journals Actinomycetes, promising tools to control plant diseases and to promote plant growth

2005 ◽  
Vol 82 (3) ◽  
pp. 85-102 ◽  
Author(s):  
C.L. Doumbou ◽  
M.K. Hamby Salove ◽  
D.L. Crawford ◽  
C. Beaulieu
Keyword(s):  
Plant Growth ◽  
Plant Pathogens ◽  
Soil Microbial Biomass ◽  
Extracellular Enzymes ◽  
Control Plant ◽  
Plant Diseases ◽  
Soil Microbial ◽  
Plant Growth Promoting ◽  
Promote Plant Growth ◽  
Growth Promoting

Actinomycetes represent a high proportion of the soil microbial biomass and have the capacity to produce a wide variety of antibiotics and of extracellular enzymes. Several strains of actinomycetes have been found to protect plants against plant diseases. This review focuses on the potential of actinomycetes as (a) source of agroactive compounds, (b) plant growth promoting organisms, and (c) biocontrol tools of plant diseases. This review also addresses examples of biological control of fungal and bacterial plant pathogens by actinomycetes species which have already reached the market or are likely to be exploited commercially within the next few years.

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