scholarly journals Bacteriophage-Host Association in the Phytoplasma Insect Vector Euscelidius variegatus

Pathogens ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 612
Author(s):  
Marta Vallino ◽  
Marika Rossi ◽  
Sara Ottati ◽  
Gabriele Martino ◽  
Luciana Galetto ◽  
...  

Insect vectors transmit viruses and bacteria that can cause severe diseases in plants and economic losses due to a decrease in crop production. Insect vectors, like all other organisms, are colonized by a community of various microorganisms, which can influence their physiology, ecology, evolution, and also their competence as vectors. The important ecological meaning of bacteriophages in various ecosystems and their role in microbial communities has emerged in the past decade. However, only a few phages have been described so far in insect microbiomes. The leafhopper Euscelidius variegatus is a laboratory vector of the phytoplasma causing Flavescence dorée, a severe grapevine disease that threatens viticulture in Europe. Here, the presence of a temperate bacteriophage in E. variegatus (named Euscelidius variegatus phage 1, EVP-1) was revealed through both insect transcriptome analyses and electron microscopic observations. The bacterial host was isolated in axenic culture and identified as the bacterial endosymbiont of E. variegatus (BEV), recently assigned to the genus Candidatus Symbiopectobacterium. BEV harbors multiple prophages that become active in culture, suggesting that different environments can trigger different mechanisms, finely regulating the interactions among phages. Understanding the complex relationships within insect vector microbiomes may help in revealing possible microbe influences on pathogen transmission, and it is a crucial step toward innovative sustainable strategies for disease management in agriculture.

EUGENIA ◽  
2012 ◽  
Vol 18 (1) ◽  
Author(s):  
Christina L. Salaki ◽  
Jantje Pelealu

ABSTRACT   Insect vectors disease is a major problem for chilli crop production in North Sulawesi. The effect is significant in decreasing crop production. The use of plant-derived insecticide is potential and environmentally friendly way in controlling the insect, as a form of integrated pest management. Seeds of Bitung (Barringtonia asiatica) and seeds of soursop (Annona muricata) plants can be used as an organic insectiside to control the several types of insect vectors  in pepper crop. The purpose of this study was to determine effects of the application of extracts of B. asiatica and A. muricata on the growth of insect vector (Aphis gossypii) in pepper and and determine the extracts’s lethal level.  This research was conducted in the Green House of Plant Pests and Diseases Department of the Faculty of Agriculture Unsrat Manado, for 6 months time. The research used a complete randomized design consisting of 6 treatments;  each treatment was consisted of three replications. The results showed that the percentage of dead insects assay (Aphis gossypii) increased as the concentration of the extract used increased. This study found that the concentration of soursop seed extract at 50 g / l and a concentration of 1.75% Bitung seed extract was the best to be used as a botanical insecticide in controlling the insect population vector (Aphis gossypii) in laboratory conditions. It has an effective lethal concentration for 93, 67% and 90.0% of all test insect population. Overall bioactivity increased the effectiveness of soursop Bitung seed extract as botanical insecticides. Keywords: Barringtonia asiatica, Annona muricata, Aphis gossypii, chilli plants ABSTRAK   Serangga vektor penyakit merupakan masalah utama bagi produksi tanaman cabai di Sulawesi Utara karena dapat menurunkan produksi. Salah satu sarana pengendalian yang memiliki peluang baik untuk dikembangkan dalam menunjang penerapan PHT adalah pemanfaatan bahan insektisida yang berasal tumbuhan. Buah bitung (Barringtonia asiatica) dan biji sirsak (Annona muricata) adalah jenis tumbuhan yang berpotensi untuk dikembangkan dan efektif terhadap beberapa jenis serangga vektor pada tanaman cabai. Tujuan penelitian ini untuk mengetahui pengaruh ekstrak B. asiatica dan A. muricata terhadap perkembangan dan daya bunuh terhadap serangga vektor (Aphis gossypii) pada tanaman cabai. Penelitian ini dilaksanakan di Green House Jurusan Hama dan Penyakit Tumbuhan Fakultas Pertanian Unsrat Manado, selama kurang lebih 6 bulan. Metode penelitian yang digunakan adalah Rancangan Acak Lengkap yang terdiri dari 6 perlakuan dan tiap perlakuan terdiri dari 3 ulangan. Hasil penelitian menunjukkan bahwa persentase kematian serangga uji (Aphis gossypii) meningkat seiring dengan meningkatnya konsentrasi ekstrak yang digunakan. Dalam penelitian ini didapati bahwa konsentrasi ekstrak biji sirsak sebesar 50 g/l dan konsentrasi ekstrak biji bitung 1,75 % sangat baik digunakan sebagai insektisida botani dalam mengendalikan populasi serangga vektor (Aphis gossypii) pada kondisi laboratorium, karena konsentrasi ini efektif mematikan sebesar 93,67 % dan 90,0 % seluruh populasi serangga uji. Keseluruhan bioaktivitas tersebut menambah keefektifan ekstrak biji sirsak dan buah bitung sebagai insektisida botani.  Eugenia Volume 18 No. 1  April 2012 Kata Kunci : Barringtonia asiatica, Annona muricata, Aphis gossypii, tanaman cabai


eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Elizabeth A Savory ◽  
Skylar L Fuller ◽  
Alexandra J Weisberg ◽  
William J Thomas ◽  
Michael I Gordon ◽  
...  

Understanding how bacteria affect plant health is crucial for developing sustainable crop production systems. We coupled ecological sampling and genome sequencing to characterize the population genetic history of Rhodococcus and the distribution patterns of virulence plasmids in isolates from nurseries. Analysis of chromosome sequences shows that plants host multiple lineages of Rhodococcus, and suggested that these bacteria are transmitted due to independent introductions, reservoir populations, and point source outbreaks. We demonstrate that isolates lacking virulence genes promote beneficial plant growth, and that the acquisition of a virulence plasmid is sufficient to transition beneficial symbionts to phytopathogens. This evolutionary transition, along with the distribution patterns of plasmids, reveals the impact of horizontal gene transfer in rapidly generating new pathogenic lineages and provides an alternative explanation for pathogen transmission patterns. Results also uncovered a misdiagnosed epidemic that implicated beneficial Rhodococcus bacteria as pathogens of pistachio. The misdiagnosis perpetuated the unnecessary removal of trees and exacerbated economic losses.


mSystems ◽  
2018 ◽  
Vol 3 (2) ◽  
pp. e00168-17 ◽  
Author(s):  
Michelle Heck

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.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nathalie Arricau-Bouvery ◽  
Sybille Duret ◽  
Marie-Pierre Dubrana ◽  
Delphine Desqué ◽  
Sandrine Eveillard ◽  
...  

AbstractThe flavescence dorée phytoplasma undergoes a propagative cycle in its insect vectors by first interacting with the insect cell surfaces, primarily in the midgut lumen and subsequently in the salivary glands. Adhesion of flavescence dorée phytoplasma to insect cells is mediated by the adhesin VmpA. We hypothesize that VmpA may have lectin-like activity, similar to several adhesins of bacteria that invade the insect gut. We first demonstrated that the luminal surface of the midgut and the basal surface of the salivary gland cells of the natural vector Scaphoideus titanus and those of the experimental vector Euscelidius variegatus were differentially glycosylated. Using ELISA, inhibition and competitive adhesion assays, and protein overlay assays in the Euva-6 insect cell line, we showed that the protein VmpA binds insect proteins in a lectin-like manner. In conclusion, the results of this study indicate that N-acetylglucosamine and mannose present on the surfaces of the midgut and salivary glands serve as recognition sites for the phytoplasma adhesin VmpA.


Author(s):  
R. A. Nunamaker ◽  
C. E. Nunamaker ◽  
B. C. Wick

Culicoides variipennis (Coquillett) is probably the most economically important species of biting midge in the U.S. due to its involvement in the transmission of bluetongue (BT) disease of sheep, cattle and ruminant wildlife, and epizootic hemorrhagic disease (EHD) of deer. Proposals have been made to recognize the eastern and western populations of this insect vector as distinct species. Others recommend use of the term “variipennis complex” until such time that the necessary biosystematic studies have been made to determine the genetic nature and/or minute morphological differences within the population structure over the entire geographic range of the species. Increasingly, students of ootaxonomy are relying on scanning electron microscopy (SEM) to assess chorionic features. This study was undertaken to provide comparative chorionic data for the C. variipennis complex.Culicoides variipennis eggs were collected from a laboratory colony maintained in Laramie, Wyoming.


Microbiology ◽  
2006 ◽  
Vol 152 (4) ◽  
pp. 1221-1230 ◽  
Author(s):  
Nabil Killiny ◽  
Brigitte Batailler ◽  
Xavier Foissac ◽  
Colette Saillard

With the aim of identifying Spiroplasma citri proteins involved in transmission by the leafhopper Circulifer haematoceps, protein maps of four transmissible and four non-transmissible strains were compared. Total cell lysates of strains were analysed by two-dimensional gel electrophoresis using commercially available immobilized pH gradients (IPGs) covering a pH range of 4–7. Approximately 530 protein spots were visualized by silver staining and the resulting protein spot patterns for the eight strains were found to be highly similar. However, comparison using PDQuest 2-D analysis software revealed two trains of protein spots that were present only in the four transmissible strains. Using MALDI-TOF (matrix-assisted laser desorption/ionization time-of-flight) mass spectrometry and a nearly complete S. citri protein database, established during the still-ongoing S. citri GII-3-3X genome project, the sequences of both proteins were deduced. One of these proteins was identified in the general databases as adhesion-related protein (P89) involved in the attachment of S. citri to gut cells of the insect vector. The second protein, with an apparent molecular mass of 32 kDa deduced from the electrophoretic mobility, could not be assigned to a known protein and was named P32. The P32-encoding gene (714 bp) was carried by a large plasmid of 35·3 kbp present in transmissible strains and missing in non-transmissible strains. PCR products with primers designed from the p32 gene were obtained only with genomic DNA isolated from transmissible strains. Therefore, P32 has a putative role in the transmission process and it could be considered as a marker for S. citri leafhopper transmissibility. Functional complementation of a non-transmissible strain with the p32 gene did not restore the transmissible phenotype, despite the expression of P32 in the complemented strain. Electron microscopic observations of salivary glands of leafhoppers infected with the complemented strain revealed a close contact between spiroplasmas and the plasmalemma of the insect cells. This further suggests that P32 protein contributes to the association of S. citri with host membranes.


2017 ◽  
Vol 10 (1) ◽  
pp. 01-08
Author(s):  
Anderson Gonçalves da Silva ◽  
Arlindo Leal Boiça Junior ◽  
Bruno Henrique Sardinha de Souza ◽  
Eduardo Neves Costa ◽  
James da Silva Hoelhert ◽  
...  

Resumo. A cultura do feijoeiro pode ser infestada por insetos que afetam a produção antes e após a colheita, tendo como estimativa de perdas causadas nos rendimentos pelas pragas variando de 33 a 86%. Dentre essas pragas a mosca-branca Bemisia tabaci (Genn.) Autor merece destaque. Esta ocasiona danos diretos decorrentes de sua alimentação e indiretos que ocorrem por meio da excreção açucarada de honeydew ou “mela” e simbiose com a fumagina. No entanto, o dano mais sério causado pela B. tabaci é a transmissão de viroses como o mosaico-dourado-do-feijoeiro, provocando perdas econômicas que podem variar de 30% a 100%. Desse modo, o objetivo do presente estudo é disponibilizar informações a respeito de aspectos importantes de B. tabaci, como: histórico e distribuição geográfica, bioecologia e dinâmica populacional, plantas hospedeiras, métodos de controle adotados, dentre outros, a fim de se fornecer subsídios para futuras pesquisas sobre a mosca-branca em feijão.Whitefly Bemisia tabaci (Genn.) (Hemiptera: Aleyrodidae) in common beans: General characteristics, bioecology, and methods of controlAbstract. Common bean plants are infested by insects, which can ultimately affect the crop production before and after harvest, with estimated losses ranging from 33 to 86%. Among the insect pests infesting the common beans the whitefly Bemisia tabaci (Genn.) stands out. This species cause direct injury by feeding on the plants and indirect injury by excreting sugary honeydew that is after colonized by the sooty mold. In addition, the most serious damage caused by B. tabaci is the transmission of virus diseases, especially the common bean golden mosaic, responsible for economic losses varying from 30 to 100%. This review aims at providing information on important aspects of B. tabaci including its geographical distribution, bioecology, population dynamics, host plants, and methods of pest control. We expect that this review can provide valuable subsidies for future studies on the whitefly in common beans.


2021 ◽  
pp. 3-8
Author(s):  
Ю.А. Шнейдер ◽  
Е.В. Каримова ◽  
Ю.Н. Приходько ◽  
Е.Н. Лозовая ◽  
Т.С. Живаева

Томат – важнейшая овощная культура с ежегодным увеличением объемов его производства во всем мире. В Российской Федерации последние несколько лет активно развиваются предприятия защищенного грунта, специализирующиеся на производстве томатов. Вместе с тем растения томата поражают более 200 различных вредителей и болезней. Возбудители вирусных болезней растений – важный ограничивающий фактор для многих отраслей растениеводства, в том числе овощеводства. В последние годы в европейских странах производство томатов в открытом и защищенном грунте пострадало от серьезных потерь, вызванных, главным образом, вирусными фитопатогенами. В статье представлен обзор трех наиболее опасных вирусов, возбудителей болезней томатов – коричневой морщинистости плодов томата, мозаики пепино, пятнистого увядания томата. Эти вирусы неоднократно были выявлены в целом ряде стран практически на всех континентах и вызвали значительные экономические потери в странах своего распространения. Ввиду очень быстрого распространения и обнаружения опасных вирусов томата в ряде стран, занимающихся производством и дальнейшим экспортом семян и плодов томатов, Федеральная служба по ветеринарному и фитосанитарному надзору Российской Федерации (Россельхознадзор) с 27 июля 2020 года ввела в качестве временной карантинной фитосанитарной меры требование об отсутствии этих вирусов в семенах, посадочном материале и плодах растений-хозяев при их ввозе и перемещении по территории Российской Федерации. Результаты анализов фитосанитарного риска, проведенных в ФГБУ «ВНИИКР» в 2020 году, показали, что вирусы коричневой морщинистости плодов томата, мозаики пепино и пятнистого увядания томата соответствуют критериям карантинных для Российской Федерации организмов, вирусы способны проникнуть на территорию страны с подкарантинной продукцией, распространиться и нанести существенный ущерб развитию сельского хозяйства и экономической деятельности страны. Tomato is the most important vegetable crop with an annual increase in its production worldwide. In the Russian Federation, greenhouse industry specializing in the production of tomatoes have been actively developing over the past few years. At the same time, tomato plants affect more than 200 different pests and diseases. Pathogens of viral diseases of plants are an important limiting factor for many branches of crop production, including vegetable growing. In recent years, in European countries, the production of tomatoes in open field and greenhouses has suffered from serious losses caused mainly by viral phytopathogens. The article presents an overview of the three most dangerous viruses, pathogens of tomato diseases – tomato brown rugose fruit virus (ToBRFV), pepino mosaic virus (PepMV) and tomato spotted wilt virus (TSWV). These viruses have been repeatedly detected in a number of countries on almost all continents and have caused significant economic losses in the countries of their distribution. In view of the very rapid spread and detection of dangerous tomato viruses in a number of countries engaged in the production and further export of tomato seeds and fruits, Rosselkhoznadzor, from July 27, 2020, introduced as a temporary quarantine phytosanitary measure the requirement that these viruses are not present in seeds, planting material and fruits of host plants when they are imported and moved through the territory of the Russian Federation. The results of the phytosanitary risk analyses conducted at the Federal State Budgetary Institution «VNIIKR» in 2020 showed that ToBRFV, PepMV and TSWV meet the criteria of quarantine organisms for the Russian Federation, viruses are able to enter the territory of the country with quarantined products, spread and cause significant damage to the development of agriculture and economic activity of the country.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Fabio Quaglino ◽  
Francesco Sanna ◽  
Abdelhameed Moussa ◽  
Monica Faccincani ◽  
Alessandro Passera ◽  
...  

AbstractBois noir, a disease of the grapevine yellows complex, is associated with ‘Candidatus Phytoplasma solani’ and transmitted to grapevines in open fields by the cixiids Hyalesthes obsoletus and Reptalus panzeri. In vine-growing areas where the population density of these vectors is low within the vineyard, the occurrence of bois noir implies the existence of alternative vectors. The aim of this study was to identify alternative vectors through screening of the Auchenorrhyncha community, phytoplasma typing by stamp gene sequence analyses, and transmission trials. During field activities, conducted in Northern Italy in a vineyard where the bois noir incidence was extremely high, nine potential alternative insect vectors were identified according to high abundance in the vineyard agro-ecosystem, high infection rate, and harbouring phytoplasma strains characterized by stamp gene sequence variants found also in symptomatic grapevines. Transmission trials coupled with molecular analyses showed that at least eight species (Aphrodes makarovi, Dicranotropis hamata, Dictyophara europaea, Euscelis incisus, Euscelidius variegatus, Laodelphax striatella, Philaenus spumarius, and Psammotettix alienus/confinis) are alternative vectors of ‘Candidatus Phytoplasma solani’ to grapevines. These novel findings highlight that bois noir epidemiology in vineyard agro-ecosystems is more complex than previously known, opening up new perspectives in the disease management.


2020 ◽  
Vol 16 (3) ◽  
pp. e1007967 ◽  
Author(s):  
Sylvie Malembic-Maher ◽  
Delphine Desqué ◽  
Dima Khalil ◽  
Pascal Salar ◽  
Bernard Bergey ◽  
...  

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