Soilborne Microbial Plant Pathogens and Disease Management, Volume One

2019 ◽  
Author(s):  
P. Narayanasamy
Keyword(s):  
Disease Management ◽  
Management Volume ◽  
Plant Pathogens

scholarly journals Spray-induced gene silencing for disease control is dependent on the efficiency of pathogen RNA uptake

2021 ◽  
Author(s):  
Lulu Qiao ◽  
Chi Lan ◽  
Luca Capriotti ◽  
Audrey Ah-Fong ◽  
Jonatan Nino Sanchez ◽  
...  
Keyword(s):  
Disease Management ◽  
Plant Disease ◽  
Plant Pathogens ◽  
Developmental Stages ◽  
Pathogenic Fungi ◽  
Cell Types ◽  
Uptake Efficiency ◽  
Fungal Plant Pathogens ◽  
Plant Disease Management ◽  
Fungal Genes

AbstractRecent discoveries show that fungi can take up environmental RNA, which can then silence fungal genes through environmental RNA interference. This discovery prompted the development of Spray-Induced Gene Silencing (SIGS) for plant disease management. In this study, we aimed to determine the efficacy of SIGS across a variety of eukaryotic microbes. We first examined the efficiency of RNA uptake in multiple pathogenic and non-pathogenic fungi, and an oomycete pathogen. We observed efficient double-stranded RNA (dsRNA) uptake in the fungal plant pathogens Botrytis cinerea, Sclerotinia sclerotiorum, Rhizoctonia solani, Aspergillus niger, and Verticillium dahliae, but no uptake in Colletotrichum gloeosporioides, and weak uptake in a beneficial fungus, Trichoderma virens. For the oomycete plant pathogen, Phytophthora infestans, RNA uptake was limited, and varied across different cell types and developmental stages. Topical application of dsRNA targeting virulence-related genes in the pathogens with high RNA uptake efficiency significantly inhibited plant disease symptoms, whereas the application of dsRNA in pathogens with low RNA uptake efficiency did not suppress infection. Our results have revealed that dsRNA uptake efficiencies vary across eukaryotic microbe species and cell types. The success of SIGS for plant disease management can largely be determined by the pathogen RNA uptake efficiency.

scholarly journals Hormetic Effects of Carbendazim on the Virulence of Botrytis cinerea

Plant Disease ◽  
2018 ◽  
Vol 102 (5) ◽  
pp. 886-891 ◽  
Author(s):  
Menglong Cong ◽  
Shun He ◽  
Hongju Ma ◽  
Guoqing Li ◽  
Fuxing Zhu
Keyword(s):  
Hydrogen Peroxide ◽  
Disease Management ◽  
Botrytis Cinerea ◽  
Time Course ◽  
Plant Pathogens ◽  
Pathogenic Fungus ◽  
Physiological Mechanism ◽  
Potato Dextrose Agar ◽  
Direct Stimulation ◽  
Sublethal Doses

The ascomycete plant-pathogenic fungus Botrytis cinerea infects more than 1,400 plant species worldwide. Stimulatory effects of sublethal doses of fungicides on plant pathogens are of close relevance to disease management. In the present study, stimulatory effects of carbendazim on the virulence of B. cinerea to cucumber plants were investigated. Spraying carbendazim on cucumber plants at 3 to 200 μg/ml had stimulatory effects on the virulence of carbendazim-resistant isolates of B. cinerea and the maximum percent stimulations were 16.7 and 13.5% for isolates HBtom451 and HBstr491, respectively. Preconditioned mycelia (i.e., mycelia grown on potato dextrose agar [PDA] amended with carbendazim at concentrations of 10, 50, or 200 μg/ml) also showed increased virulence, and the maximum percent stimulations for isolates HBtom451 and HBstr491 were 7.9 and 9.5%, respectively. Compared with mycelia grown on PDA without carbendazim, virulence stimulation magnitudes of spraying carbendazim on leaves increased moderately but the concentrations of carbendazim that elicited the maximum stimulation increased 20- and 8-fold for preconditioned isolates HBtom451 and HBstr491, respectively. The time course of infection indicated that virulence stimulation was mediated by a direct stimulation mechanism. Studies of the physiological mechanism for stimulation demonstrated that carbendazim had no significant effects on tolerance to hydrogen peroxide, or on oxalic acid production in B. cinerea. These studies will deepen our understanding of quantitative features of hormetic effects of sublethal doses of fungicides on plant pathogens.

scholarly journals Biosensor Technologies for Early Detection and Quantification of Plant Pathogens

2021 ◽  
Vol 9 ◽  
Author(s):  
Kazbek Dyussembayev ◽  
Prabhakaran Sambasivam ◽  
Ido Bar ◽  
Jeremy C. Brownlie ◽  
Muhammad J. A. Shiddiky ◽  
...  
Keyword(s):  
Disease Management ◽  
Early Detection ◽  
Plant Pathogen ◽  
Pathogen Detection ◽  
Plant Disease ◽  
Plant Pathogens ◽  
Financial Burden ◽  
Management Strategies ◽  
Disease Diagnostics ◽  
Plant Pathogen Detection

Plant pathogens are a major reason of reduced crop productivity and may lead to a shortage of food for both human and animal consumption. Although chemical control remains the main method to reduce foliar fungal disease incidence, frequent use can lead to loss of susceptibility in the fungal population. Furthermore, over-spraying can cause environmental contamination and poses a heavy financial burden on growers. To prevent or control disease epidemics, it is important for growers to be able to detect causal pathogen accurately, sensitively, and rapidly, so that the best practice disease management strategies can be chosen and enacted. To reach this goal, many culture-dependent, biochemical, and molecular methods have been developed for plant pathogen detection. However, these methods lack accuracy, specificity, reliability, and rapidity, and they are generally not suitable for in-situ analysis. Accordingly, there is strong interest in developing biosensing systems for early and accurate pathogen detection. There is also great scope to translate innovative nanoparticle-based biosensor approaches developed initially for human disease diagnostics for early detection of plant disease-causing pathogens. In this review, we compare conventional methods used in plant disease diagnostics with new sensing technologies in particular with deeper focus on electrochemical and optical biosensors that may be applied for plant pathogen detection and management. In addition, we discuss challenges facing biosensors and new capability the technology provides to informing disease management strategies.

scholarly journals Plant and Fungal Genome Editing to Enhance Plant Disease Resistance Using the CRISPR/Cas9 System

2021 ◽  
Vol 12 ◽  
Author(s):  
Narayan Chandra Paul ◽  
Sung-Won Park ◽  
Haifeng Liu ◽  
Sungyu Choi ◽  
Jihyeon Ma ◽  
...  
Keyword(s):  
Disease Resistance ◽  
Disease Management ◽  
Genome Editing ◽  
Plant Disease Resistance ◽  
Crop Production ◽  
Plant Disease ◽  
Plant Pathogens ◽  
Crop Protection ◽  
Fungal Genome ◽  
Plant Disease Management

Crop production has been substantially reduced by devastating fungal and oomycete pathogens, and these pathogens continue to threaten global food security. Although chemical and cultural controls have been used for crop protection, these involve continuous costs and time and fungicide resistance among plant pathogens has been increasingly reported. The most efficient way to protect crops from plant pathogens is cultivation of disease-resistant cultivars. However, traditional breeding approaches are laborious and time intensive. Recently, the CRISPR/Cas9 system has been utilized to enhance disease resistance among different crops such as rice, cacao, wheat, tomato, and grape. This system allows for precise genome editing of various organisms via RNA-guided DNA endonuclease activity. Beyond genome editing in crops, editing the genomes of fungal and oomycete pathogens can also provide new strategies for plant disease management. This review focuses on the recent studies of plant disease resistance against fungal and oomycete pathogens using the CRISPR/Cas9 system. For long-term plant disease management, the targeting of multiple plant disease resistance mechanisms with CRISPR/Cas9 and insights gained by probing fungal and oomycete genomes with this system will be powerful approaches.

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 Understanding Yield Loss and Pathogen Biology to Improve Disease Management: Septoria Nodorum Blotch - A Case Study in Wheat

Plant Disease ◽  
2018 ◽  
Vol 102 (4) ◽  
pp. 696-707 ◽  
Author(s):  
Andrea Ficke ◽  
Christina Cowger ◽  
Gary Bergstrom ◽  
Guro Brodal
Keyword(s):  
Disease Management ◽  
Plant Pathogens ◽  
Management Practices ◽  
Yield Loss ◽  
Control Measures ◽  
Crop Loss ◽  
Yield Losses ◽  
Disease Epidemiology ◽  
Economic Thresholds ◽  
Host Pathogen

The estimated potential yield losses caused by plant pathogens is up to 16% globally and most research in plant pathology aims to reduce yield loss in our crops directly or indirectly. Yield losses caused by a certain disease depend not only on disease severity, but also on the weather factors, the pathogen’s aggressiveness, and the ability of the crop to compensate for reduced photosynthetic area. The yield loss-disease relationship in a certain host-pathogen system might therefore change from year to year, making predictions for yield loss very difficult at the regional or even at the farmer’s level. However, estimating yield losses is essential to determine disease management thresholds at which acute control measures such as fungicide applications, or strategic measures such as crop rotation or use of resistant cultivars are economically and environmentally sensible. Legislation in many countries enforces implementation of integrated pest management (IPM), based on economic thresholds at which the costs due to a disease justify the costs for its management. Without a better understanding of the relationship between disease epidemiology and yield loss, we remain insufficiently equipped to design adequate IPM strategies that will be widely adapted in agriculture. Crop loss studies are resource demanding and difficult to interpret for one particular disease, as crops are usually not invaded by only one pest or pathogen at a time. Combining our knowledge on disease epidemiology, crop physiology, yield development, damage mechanisms involved, and the effect of management practices can help us to increase our understanding of the disease-crop loss relationship. The main aim of this paper is to review and analyze the literature on a representative host-pathogen relationship in an important staple food crop to identify knowledge gaps and research areas to better assess yield loss and design management strategies based on economic thresholds.

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