scholarly journals Screening potential insect vectors in a museum biorepository reveals undiscovered diversity of plant pathogens in natural areas

2021 ◽  
Author(s):  
Valeria Trivellone ◽  
Wei Wei ◽  
Luisa Filippin ◽  
Christopher H. Dietrich
Keyword(s):  
Plant Pathogens ◽  
Insect Vectors ◽  
Natural Areas

scholarly journals Screening potential insect vectors in a museum biorepository reveals undiscovered diversity of plant pathogens in natural areas

2021 ◽  
Author(s):  
Valeria Trivellone ◽  
Wei Wei ◽  
Luisa Filippin ◽  
Christopher Dietrich
Keyword(s):  
Plant Pathogens ◽  
Insect Vectors ◽  
Natural Areas ◽  
Potential Threat ◽  
Natural Habitats ◽  
Pcr Screening ◽  
New Associations ◽  
Vector Borne ◽  
Phloem Feeding ◽  
Untapped Resource

Phytoplasmas (Mollicutes, Acholeplasmataceae), vector-borne obligate bacterial plant-parasites, infect nearly 1,000 plant species and unknown numbers of insects, mainly leafhoppers (Hemiptera, Deltocephalinae), which play a key role in transmission and epidemiology. Although the plant-phytoplasma-insect association has been evolving for >300 million years, nearly all known phytoplasmas have been discovered as a result of the damage inflicted by phytoplasma diseases on crops. Few efforts have been made to study phytoplasmas occurring in non-economically important plants in natural habitats. In this study, a sub-sample of leafhopper specimens preserved in a large museum biorepository was analyzed to unveil potential new associations. PCR screening for phytoplasmas performed on 227 phloem-feeding leafhoppers collected worldwide from natural habitats revealed the presence of 6 different previously unknown phytoplasma strains. This indicates that museum collections of herbivorous insects represent a rich and largely untapped resource for discovery of new plant pathogens, that natural areas worldwide harbor a diverse but largely undiscovered diversity of phytoplasmas and potential insect vectors, and that independent epidemiological cycles occur in such habitats, posing a potential threat of disease spillover into agricultural systems. Larger-scale future investigations will contribute to a better understanding of phytoplasma genetic diversity, insect host range, and insect-borne phytoplasma transmission and provide an early warning for the emergence of new phytoplasma diseases across global agroecosystems.

scholarly journals What is pathogen-mediated insect superabundance?

2020 ◽  
Vol 17 (170) ◽  
pp. 20200229
Author(s):  
Ruairí Donnelly ◽  
Christopher A. Gilligan
Keyword(s):  
Environmental Factors ◽  
Field Data ◽  
Plant Pathogens ◽  
Landscape Scale ◽  
Sub Saharan Africa ◽  
Insect Vectors ◽  
Vector Abundance ◽  
Sub Saharan ◽  
Definition Of

When increasing abundance of insect vectors is manifest across multiple fields of a crop at the landscape scale, the phenomenon is sometimes referred to as insect superabundance. The phenomenon may reflect environmental factors (i.e. environmentally mediated insect superabundance , EMiS), including climatic change. A number of pathogens, however, are also known to modify the quality of infected plants as a resource for their insect vectors. In this paper, we term increasing vector abundance when associated with pathogen modification of plants as pathogen-mediated insect superabundance (henceforth PMiS). We investigate PMiS using a new epidemiological framework. We formalize a definition of PMiS and indicate the epidemiological mechanism by which it is most likely to arise. This study is motivated by the occurrence of a particularly destructive cassava virus epidemic that has been associated with superabundant whitefly populations in sub-Saharan Africa. Our results have implications for how PMiS can be distinguished from EMiS in field data. Above all, they represent a timely foundation for further investigations into the association between insect superabundance and plant pathogens.

Made for each other: Vector-pathogen interfaces in the Huanglongbing pathosystem

2021 ◽  
Author(s):  
Nabil Killiny
Keyword(s):  
Plant Pathogens ◽  
Management Strategies ◽  
Tca Cycle ◽  
Detoxification Enzymes ◽  
Insect Vector ◽  
Insect Vectors ◽  
Plant Host ◽  
Atp Production ◽  
Molecular Features ◽  
Animal Pathogens

Citrus greening, or Huanglongbing (HLB), currently is the most destructive disease of citrus. HLB disease is putatively caused by the phloem-restricted α-proteobacterium, ‛Candidatus Liberibacter asiaticus’. This bacterium is primarily transmitted by the Asian citrus psyllid, Diaphorina citri (Hemiptera: Liviidae). Most animal pathogens are considered pathogenic to their insect vectors, whereas the relationships between plant pathogens and their insect vectors are variable. Lately, the relationship of ‛Ca. L. asiaticus’ with its insect vector, D. citri was well investigated at the molecular, biochemical, and biological levels in many studies. Herein, the findings concerning this relationship are discussed and molecular features of the acquisition of ‛Ca. L. asiaticus’ from the plant host and its growth and circulation within D. citri, as well as its transmission to plants, are presented. In addition, the effects of ‛Ca. L. asiaticus’ on the energy metabolism (respiration, TCA cycle, the ATP production), metabolic pathways, immune system, endosymbionts, and detoxification enzymes of D. citri are discussed together with other impacts such as shorter lifespan, altered feeding behavior, and higher fecundity. Overall, although ‛Ca. L. asiaticus’ has significant negative effects on its insect vector, it increases its vector fitness, indicating that it develops a mutualistic relationship with its vector. This review will help in understanding the specific interactions between ‛Ca. L. asiaticus’ and its psyllid vector in order to design innovative management strategies.

scholarly journals Integrated Management of Insect Vectors of Plant Pathogens

2020 ◽  
Author(s):  
Ravinder Singh Chandi
Keyword(s):  
Plant Pathogens ◽  
Cultural Practices ◽  
Integrated Management ◽  
Threshold Level ◽  
Small Population ◽  
Integrated Treatment ◽  
Control Measures ◽  
Insect Vectors ◽  
Single Method ◽  
Control Insect

A vector is an organism capable of transmitting pathogens from one host to another. Among the plant pathogen transmitting agencies, insect vectors are most important and various plant pathogens in crops are transmitted by insects. Insect vectors are much more hazardous because small population of vector can spread the pathogen in whole of the field or to new areas. These are difficult to manage and hence multi-pronged strategy should be adopted. To effectively manage insect vectors of plant pathogens there is a need to look into the careful timing of application of chemicals, integrated treatment with vector sampling, estimation of threshold level of vectors, assessing infection of pathogen at varying period of the year and combining insecticides with other means of control such as resistant cultivars, natural enemies, inclusion of plant products, cultural practices, biotechnology tools etc. An integration of control measures will be more effective and ecologically sound than any single method to control insect vectors of plant pathogens. The control of insect vectors with the use of various tactics should be used to reduce the severity and to delay appearance of disease.

Spread of plant pathogens and insect vectors at the northern range margin of cypress in Italy

2008 ◽  
Vol 33 (3) ◽  
pp. 307-313 ◽  
Author(s):  
Alessia Zocca ◽  
Corrado Zanini ◽  
Andrea Aimi ◽  
Gabriella Frigimelica ◽  
Nicola La Porta ◽  
...  
Keyword(s):  
Plant Pathogens ◽  
Insect Vectors ◽  
Range Margin

scholarly journals Insect Transmission of Plant Pathogens: a Systems Biology Perspective

mSystems ◽  
2018 ◽  
Vol 3 (2) ◽  
pp. e00168-17 ◽  
Author(s):  
Michelle Heck
Keyword(s):  
Systems Biology ◽  
Human Health ◽  
Plant Pathogens ◽  
Control Strategies ◽  
Global Scale ◽  
Pathogen Transmission ◽  
Effective Control ◽  
Insect Vector ◽  
Insect Vectors ◽  
Vector Systems

ABSTRACT Insect-vectored pathogens pose one of the greatest threats to plant and animal, including human, health on a global scale. Few effective control strategies have been developed to thwart the transmission of any insect-transmitted pathogen. Most have negative impacts on the environment and human health and are unsustainable. Plant pathogen transmission by insect vectors involves a combination of coevolving biological players: plant hosts, insect vectors, plant pathogens, and bacterial endosymbionts harbored by the insect. Our ability to help growers to control vector-borne disease depends on our ability to generate pathogen- and/or disease-resistant crops by traditional or synthetic approaches and to block pathogen transmission by the insect vector. Systems biology studies have led to the reexamination of existing paradigms on how pathogens interact with insect vectors, including the bacterial symbionts, and have identified vector-pathogen interactions at the molecular and cellular levels for the development of novel transmission interdiction strategies.

Freeze substitution fixation of fungal reproductive structures and spores

1989 ◽  
Vol 47 ◽  
pp. 990-991
Author(s):  
C. W. Mims ◽  
E. A. Richardson
Keyword(s):  
Plant Pathogens ◽  
Freeze Substitution ◽  
Uranyl Acetate ◽  
Chemical Fixation ◽  
Dialysis Membrane ◽  
Razor Blade ◽  
Thin Sections ◽  
Reproductive Structures ◽  
Dry Down ◽  
Diamond Knife

The advantages of freeze substitution fixation over conventional chemical fixation for preservation of ultrastructural details in fungi have been discussed by various authors. As most ascomycetes, basidiomycetes and deuteromycetes do not fix well using conventional chemical fixation protocols, freeze substitution has attracted the attention of many individuals interested in fungal ultrastructure. Thus far most workers using this technique on fungi have concentrated on thin walled somatic hyphae. However, in our laboratory we have experimented with the use of freeze substitution on a variety of fungal reproductive structures and spores with promising results.Here we present data on freeze substituted samples of sporangia of the zygomycete Umbellopsis vinacea, basidia of Exobasidium camelliae var. gracilis, developing teliospores of the smut Sporisorium sorghi, germinating teliospores of the rust Gymnosporangium clavipes, germinating conidia of the deuteromycete Cercosporidium personatum, and developing ascospores of Ascodesmis nigricans.Spores of G. clavipes and C. personatum were deposited on moist pieces of sterile dialysis membrane where they hydrated and germinated. Asci of A. nigricans developed on pieces of dialysis membrane lying on nutrient agar plates. U. vinacea was cultured on small pieces of agar-coated wire. In the plant pathogens E. camelliae var. gracilis and S. sorghi, a razor blade was used to remove smal1 pieces of infected host issue. All samples were plunged directly into liquid propane and processed for study according to Hoch.l Samples on dialysis membrane were flat embedded. Serial thin sections were cut using a diamond knife, collected on slot grids, and allowed to dry down onto Formvar coated aluminum racks. Sections were post stained with uranyl acetate and lead citrate.

Effect of Homeopathic Preparations on Lettuce, Parasitized or Not by Meloidogyne enterolobii

Homeopathy ◽  
2020 ◽  
Author(s):  
Thais Moraes Ferreira ◽  
Mariana Zandomênico Mangeiro ◽  
Alexandre Macedo Almeida ◽  
Ricardo Moreira Souza
Keyword(s):  
Plant Pathogens ◽  
Nematode Control ◽  
Plant Tolerance ◽  
Nematode Reproduction ◽  
Meloidogyne Enterolobii ◽  
Negative Effect ◽  
Meloidogyne Spp ◽  
Constant Dose ◽  
Lettuce Growth ◽  
Complementary Strategy

Abstract Background There are relatively few scientific works on the use of homeopathy to manage plant pathogens, particularly nematodes. A handful of studies focused on Meloidogyne spp. parasitizing vegetables have brought contradictory results on nematode control and enhancement of plant tolerance to parasitism. Objective Our goal was to assess the effect of Cina—a well-known anti-nematode ingredient—on Meloidogyne enterolobii parasitizing lettuce. Methods Cina was applied daily on nematode-inoculated plants, from the seedling stage until harvest. We tested an evenly spaced range of Hahnemannian concentrations (c), which were applied though irrigation with a constant dose of the ingredient. Several absolute and relative controls were employed to allow the assessment of the effect of Cina on nematode reproduction and lettuce growth. Results Cina affected growth of non-parasitized plants, both positively and negatively; this effect was modulated by the c applied and the thermal stress suffered by the plants in one of the assays. The effect of Cina on the growth of nematode-parasitized plants was neutral or negative. Cina reduced nematode reproduction by 25–36%. Conclusion Based on the moderate negative effect of Cina on M. enterolobii reproduction, it seems this ingredient may be useful as a complementary strategy for Meloidogyne control. But Cina did not enhance the tolerance of lettuce to Meloidogyne spp.

Sign in / Sign up

Export Citation Format

Share Document