disease interactions in a shared host plant: effects of pre-existing viral infection on cucurbit plant defense responses and resistance to bacterial wilt disease.both biotic and abiotic stressors can elicit broad-spectrum plant resistance against subsequent pathogen challenges. however, we currently have little understanding of how such effects influence broader aspects of disease ecology and epidemiology in natural environments where plants interact with multiple antagonists simultaneously. in previous work, we have shown that healthy wild gourd plants (cucurbita pepo ssp. texana) contract a fatal bacterial wilt infection (caused by erwinia tracheiphila ...201324155951
genetic and virulence variability among erwinia tracheiphila strains recovered from different cucurbit hosts.the causal agent of cucurbit bacterial wilt, erwinia tracheiphila, has a wide host range in the family cucurbitaceae, including economically important crops such as muskmelon (cucumis melo), cucumber (c. sativus), and squash (cucurbita spp.). genetic variability of 69 e. tracheiphila strains was investigated by repetitive-element polymerase chain reaction (rep-pcr) using boxa1r and eric1-2 primers. fingerprint profiles revealed significant variability associated with crop host; strains isolated ...201323927426
pathogen effects on vegetative and floral odours mediate vector attraction and host exposure in a complex pathosystem.pathogens can alter host phenotypes in ways that influence interactions between hosts and other organisms, including insect disease vectors. such effects have implications for pathogen transmission, as well as host exposure to secondary pathogens, but are not well studied in natural systems, particularly for plant pathogens. here, we report that the beetle-transmitted bacterial pathogen erwinia tracheiphila - which causes a fatal wilt disease - alters the foliar and floral volatile emissions of ...201222988893
surface survival and internalization of salmonella through natural cracks on developing cantaloupe fruits, alone or in the presence of the melon wilt pathogen erwinia tracheiphila.outbreaks of foodborne illness attributed to the consumption of salmonella-tainted cantaloupe have occurred repeatedly, but understanding of the ecology of salmonella on cantaloupe fruit surfaces is limited. we investigated the interactions between salmonella enterica poona, the plant pathogenic bacterium erwinia tracheiphila, and cantaloupe fruit. fruit surfaces were inoculated at the natural cracking stage by spreading s. enterica and e. tracheiphila, 20 µl at 107 cfu/ml, independently or toge ...201425147942
differential colonization dynamics of cucurbit hosts by erwinia tracheiphila.bacterial wilt is one of the most destructive diseases of cucurbits in the midwestern and northeastern united states. although the disease has been studied since 1900, host colonization dynamics remain unclear. cucumis- and cucurbita-derived strains exhibit host preference for the cucurbit genus from which they were isolated. we constructed a bioluminescent strain of erwinia tracheiphila (tedcu10-bl#9) and colonization of different cucurbit hosts was monitored. at the second-true-leaf stage, cuc ...201626926487
mixtures of plant growth-promoting rhizobacteria enhance biological control of multiple cucumber pathogens.abstract plant growth-promoting rhizobacteria (pgpr) strains inr7 (bacillus pumilus), gb03 (bacillus subtilis), and me1 (curtobacterium flaccumfaciens) were tested singly and in combinations for biological control against multiple cucumber pathogens. investigations under greenhouse conditions were conducted with three cucumber pathogens-colletotrichum orbiculare (causing anthracnose), pseudomonas syringae pv. lachrymans (causing angular leaf spot), and erwinia tracheiphila(causing cucurbit wilt ...199818944848
floral transmission of erwinia tracheiphila by cucumber beetles in a wild cucurbita pepo.cucumber beetles, acalymma vittatum (f.) and diabrotica undecipunctata howardi (barber), are specialist herbivores of cucurbits and the vector of erwinia tracheiphila (e.f. smith) holland, the causative agent of wilt disease. cucumber beetles transmit e. tracheiphila when infected frass falls onto leaf wounds at the site of beetle feeding. we show that e. tracheiphila also can be transmitted via the floral nectaries of cucurbita pepo ssp. texana l. andres (texas gourd). under field conditions, w ...201020146850
dynamics of short- and long-term association between a bacterial plant pathogen and its arthropod vector.the dynamics of association between pathogens and vectors can strongly influence epidemiology. it has been proposed that wilt disease epidemics in cucurbit populations are sustained by persistent colonization of beetle vectors (acalymma vittatum) by the bacterial phytopathogen erwinia tracheiphila. we developed a qpcr method to quantify e. tracheiphila in whole beetles and frass and used it to assess pathogen acquisition and retention following variable exposure to infected plants. we found that ...201424561664
isolation and identification of atrazine-degrading bacteria from corn field soil in fars province of this study several agricultural fields with a long history of atrazine application in fars province of iran have been explored for their potential of atrazine biodegradation. after several subculturing for a period of 300 days acclimation, leads to an enhancement of atrazine biodegradation rate. a successful enrichment culture with a high capability for atrazine degradation was obtained (88%). a combination of enrichment culture technique, in a basal salt medium containing atrazine and carbon ...200719069990
horizontal gene acquisitions, mobile element proliferation, and genome decay in the host-restricted plant pathogen erwinia tracheiphila.modern industrial agriculture depends on high-density cultivation of genetically similar crop plants, creating favorable conditions for the emergence of novel pathogens with increased fitness in managed compared with ecologically intact settings. here, we present the genome sequence of six strains of the cucurbit bacterial wilt pathogen erwinia tracheiphila (enterobacteriaceae) isolated from infected squash plants in new york, pennsylvania, kentucky, and michigan. these genomes exhibit a high pr ...201626992913
genotyping of bacteria belonging to the former erwinia genus by pcr-rflp analysis of a reca gene fragment.genotypic characterization, based on the analysis of restriction fragment length polymorphism of the reca gene fragment pcr product (reca pcr-rflp), was performed on members of the former erwinia genus. pcr primers deduced from published reca gene sequences of erwinia carotovora allowed the amplification of an approximately 730 bp dna fragment from each of the 19 erwinia species tested. amplified reca fragments were compared using rflp analysis with four endonucleases (alui, hinfi, tasi and tru1 ...200211832521
inbreeding effects on blossom volatiles in cucurbita pepo subsp. texana (cucurbitaceae).self-pollination by plants gives rise to inbreeding depression. there is increasing recognition that plant inbreeding can have significant implications for interactions between plants and other organisms, including insects and pathogens. many of these interactions are mediated by plant-derived volatiles, but the effects of inbreeding on volatile production have not previously been investigated. we examined variation in flower volatile production by the wild gourd cucurbita pepo subsp. texana as ...200621642122
effects of plant diversity and time of colonization on an herbivore-plant interaction.experimental field plantings showed that plant diversity strongly affected the population dynamics of a specialist herbivore, the striped cucumber beetle, acalymma vittata (fab.) (coleoptera: chrysomelidae). population densities over time were characterized by two peaks in numbers (from colonization and reproduction, respectively) and were consistently higher in cucumber monocultures (cucumis sativus l.) than in polycultures of cucumbers, corn (zea mays l.), and broccoli (brassica oleracea l.). ...197928310287
insect frass as a pathway for transmission of bacterial wilt of cucurbits.insects that vector diseases of plants are of critical concern to agriculture, but relationships between the vectors and pathogens often are poorly understood. in this study, we present research on vector relationships between the striped cucumber beetle, acalymma vittatum (f.) (coleoptera: chrysomelidae), and the pathogen that causes bacterial wilt of cucurbits, erwinia tracheiphila (smith) (enterobacteriales: enterobacteriaceae). we studied how the bacteria were retained in the gut of the beet ...200919389288
draft genome sequence of erwinia tracheiphila, an economically important bacterial pathogen of cucurbits.erwinia tracheiphila is one of the most economically important pathogens of cucumbers, melons, squashes, pumpkins, and gourds in the northeastern and midwestern united states, yet its molecular pathology remains uninvestigated. here, we report the first draft genome sequence of an e. tracheiphila strain isolated from an infected wild gourd (cucurbita pepo subsp. texana) plant. the genome assembly consists of 7 contigs and includes a putative plasmid and at least 20 phage and prophage elements.201526044415
using trap crops for control of acalymma vittatum (coleoptera: chrysomelidae) reduces insecticide use in butternut squash.striped cucumber beetle, acalymma vittatum f., is the primary insect pest of cucurbit crops in the northeastern united states. adult beetles colonize squash crops from field borders, causing feeding damage at the seedling stage and transmitting bacterial wilt erwinia tracheiphila hauben et al. 1999. conventional control methods rely on insecticide applications to the entire field, but surrounding main crops with a more attractive perimeter could reduce reliance on insecticides. a. cittatum shows ...200919610425
modified inoculation and disease assessment methods reveal host specificity in erwinia tracheiphila-cucurbitaceae interactions.we conducted a greenhouse trial to determine specific compatible interactions between erwinia tracheiphila strains and cucurbit host species. using a modified inoculation system, e. tracheiphila strains hca1-5n, uniscu1-1n, and mispsq-n were inoculated to cucumber (cucumis sativus) cv. 'sweet burpless', melon (cucumis melo) cv. 'athena hybrid', and squash (cucubita pepo) cv. 'early summer crookneck'. we observed symptoms and disease progression for 30 days; recorded the number of days to wilting ...201526522078
antimicrobial nectar inhibits a florally transmitted pathogen of a wild cucurbita pepo (cucurbitaceae).• premise of the study: floral nectars of many species contain antimicrobial chemicals, but their function in nectar is subject to debate. previously, we have shown that erwinia tracheiphila, the causative agent of bacterial wilt disease in cucurbits, can be transmitted via the floral nectaries. • methods: we used a disk diffusion assay (dda) to determine the antimicrobial effects of nectar from a wild gourd on lawns of escherichia coli and erwinia tracheiphila. we also used e. tracheiphila to i ...201021622472
investigating the phylogenetic range of gibberellin biosynthesis in bacteria.certain plant-associated microbes can produce gibberellin (ga) phytohormones, as first described for the rice fungal pathogen gibberella fujikuroi and, more recently, for bacteria, including several rhizobia and the rice bacterial pathogen xanthomonas oryzae pv. oryzicola. the relevant enzymes are encoded by a biosynthetic operon that exhibits both a greater phylogenetic range and scattered distribution among plant-associated bacteria. here, the phylogenetic distribution of this operon was inves ...201728425831
the serological relationship between erwinia tracheiphila and species of shigella. 194616561192
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