| spiroplasma-like organisms closely associated with the gut in five leafhopper species (hemiptera: cicadellidae). | spiroplasmas are bacteria in the class mollicutes that are frequently associated with insects and/or plants. here, we describe the ultrastructure, localization, and occurrence of apparent commensal/symbiotic spiroplasma-like organisms (slos) in the midgut and hindgut of five leafhopper species from laboratory-reared colonies. those found in dalbulus elimatus, endria inimica, and macrosteles quadrilineatus were long and tubular shaped, whereas those in dalbulus maidis and graminella nigrifrons we ... | 2010 | 20978745 |
| phytoplasma protein effector sap11 enhances insect vector reproduction by manipulating plant development and defense hormone biosynthesis. | phytoplasmas are insect-transmitted phytopathogenic bacteria that can alter plant morphology and the longevity and reproduction rates and behavior of their insect vectors. there are various examples of animal and plant parasites that alter the host phenotype to attract insect vectors, but it is unclear how these parasites accomplish this. we hypothesized that phytoplasmas produce effectors that modulate specific targets in their hosts leading to the changes in plant development and insect perfor ... | 2011 | 22065743 |
| Phytoplasma effector SAP54 induces indeterminate leaf-like flower development in Arabidopsis plants. | Phytoplasmas are insect-transmitted bacterial plant pathogens that cause considerable damage to a diverse range of agricultural crops globally. Symptoms induced in infected plants suggest that these phytopathogens may modulate developmental processes within the plant host. We report herein that Aster Yellows phytoplasma strain Witches' Broom (AY-WB) readily infects the model plant Arabidopsis (Arabidopsis thaliana) ecotype Columbia, inducing symptoms that are characteristic of phytoplasma infect ... | 2011 | 21849514 |
| transmission and retention of salmonella enterica by phytophagous hemipteran insects. | several pest insects of human and livestock habitations are known as vectors of salmonella enterica; however, the role of plant-feeding insects as vectors of s. enterica to agricultural crops remains unexamined. using a hemipteran insect pest-lettuce system, we investigated the potential for transmission and retention of s. enterica. specifically, macrosteles quadrilineatus and myzus persicae insects were fed s. enterica-inoculated lettuce leaf discs or artificial liquid diets confined in parafi ... | 2014 | 24973069 |
| influence of prgh on the persistence of ingested salmonella enterica in the leafhopper macrosteles quadrilineatus. | phytophagous insects can encounter salmonella enterica on contaminated plant surfaces and transmit externally adhered and internalized bacteria on and among leaves. excretion of ingested s. enterica by the leafhopper macrosteles quadrilineatus has been previously reported; however, the sites of persistence of ingested bacteria remain undetermined. fluorescence microscopy revealed the presence and persistence of s. enterica in various organs of m. quadrilineatus fed an inoculated diet for 12 h an ... | 2015 | 26150468 |
| interaction of phytophagous insects with salmonella enterica on plants and enhanced persistence of the pathogen with macrosteles quadrilineatus infestation or frankliniella occidentalis feeding. | recently, most foodborne illness outbreaks of salmonellosis have been caused by consumption of contaminated fresh produce. yet, the mechanisms that allow the human pathogen salmonella enterica to contaminate and grow in plant environments remain poorly described. we examined the effect of feeding by phytophagous insects on survival of s. enterica on lettuce. larger s. enterica populations were found on leaves infested with macrosteles quadrilineatus. in contrast, pathogen populations among plant ... | 2013 | 24205384 |
| seasonal patterns of aster leafhopper (hemiptera: cicadellidae) abundance and aster yellows phytoplasma infectivity in wisconsin carrot fields. | in wisconsin, vegetable crops are threatened annually by the aster yellows phytoplasma (ayp), which is obligately transmitted by the aster leafhopper. using a multiyear, multilocation data set, seasonal patterns of leafhopper abundance and infectivity were modeled. a seasonal aster yellows index (ayi) was deduced from the model abundance and infectivity predictions to represent the expected seasonal risk of pathogen transmission by infectious aster leafhoppers. the primary goal of this study was ... | 2013 | 23726058 |
| factors influencing aster leafhopper (hemiptera: cicadellidae) abundance and aster yellows phytoplasma infectivity in wisconsin carrot fields. | in wisconsin, vegetable crops are threatened annually by infection of the aster yellows phytoplasma (ayp), the causal agent of aster yellows (ay) disease, vectored by the aster leafhopper, macrosteles quadrilineatus forbes. aster leafhopper abundance and infectivity are influenced by processes operating across different temporal and spatial scales. we applied a multilevel modeling approach to partition variance in multifield, multiyear, pest scouting data sets containing temporal and spatial cov ... | 2013 | 23726057 |
| detection and variability of aster yellows phytoplasma titer in its insect vector, macrosteles quadrilineatus (hemiptera: cicadellidae). | the aster yellows phytoplasma (ayp) is transmitted by the aster leafhopper, macrosteles quadrilineatus forbes, in a persistent and propagative manner. to study ayp replication and examine the variability of ayp titer in individual aster leafhoppers, we developed a quantitative real-time polymerase chain reaction assay to measure ayp concentration in insect dna extracts. absolute quantification of ayp dna was achieved by comparing the amplification of unknown amounts of an ayp target gene sequenc ... | 2011 | 22299339 |
| small, smaller, smallest: the origins and evolution of ancient dual symbioses in a phloem-feeding insect. | many insects rely on bacterial symbionts with tiny genomes specialized for provisioning nutrients lacking in host diets. xylem sap and phloem sap are both deficient as insect diets, but differ dramatically in nutrient content, potentially affecting symbiont genome evolution. for sap-feeding insects, sequenced symbiont genomes are available only for phloem-feeding examples from the suborder sternorrhyncha and xylem-feeding examples from the suborder auchenorrhyncha, confounding comparisons. we se ... | 2013 | 23918810 |
| aster leafhopper survival and reproduction, and aster yellows transmission under static and fluctuating temperatures, using ddpcr for phytoplasma quantification. | aster yellows (ay) is an important disease of brassica crops and is caused by candidatus phytoplasma asteris and transmitted by the insect vector, aster leafhopper (macrosteles quadrilineatus). phytoplasma-infected aster leafhoppers were incubated at various constant and fluctuating temperatures ranging from 0 to 35 °c with the reproductive host plant barley (hordium vulgare). at 0 °c, leafhopper adults survived for 18 days, but failed to reproduce, whereas at 35 °c insects died within 18 days, ... | 2018 | 29321551 |