Friend or foe?: a plant's induced response to an omnivore

Omnivorous natural enemies of herbivores consume plant-based resources and may elicit induced resistance in their host plant. A greater induction threshold for damage produced by omnivorous predators than for strict herbivores might be expected if omnivore performance is enhanced on noninduced plants, allowing them to reduce future levels of herbivory. Currently, it is not known if a plant responds to feeding by omnivorous predators and by herbivores similarly. To examine this question, we chose herbivore and omnivore species that produce the same kind of quantifiable damage to cotton leaves, enabling us to control statistically for the intensity of plant damage, and ask whether plant responses differed depending on the identity of the damaging species. We first compared changes in plant peroxidase activity, gossypol gland number and density, and leaf area in response to feeding by the spider mite Tetranychus turkestani (Ugarov and Nikolski) (an herbivore) and by one of the mite's principal natural enemies, the western flower thrips Frankliniella occidentalis (Pergande) (an omnivore). Both species increased the activity of peroxidase, but when we controlled for the amount of damage, the peroxidase activity of mite-damaged plants was higher than that of thrips-damaged plants. We also found that thrips, but not spider mites, increased the density of gossypol glands in the second true leaf. In a second experiment we included an additional herbivore, the bean thrips Caliothrips fasciatus (Pergande), to see if the different responses of cotton to thrips and mite herbivory we first observed were attributable to differences in trophic function (herbivore versus omnivore) or to other differences in feeding generated by thrips versus mites. Cotton plants exhibited the same pattern of induced responses (elevated peroxidase, increased number of glands, reduced leaf area) to herbivory generated by the bean thrips (an herbivore) and western flower thrips (an omnivore), suggesting that trophic function was not a key determinant of plant response. Thrips-damaged plants again showed a significantly higher density of gossypol glands than did mite-damaged plants. Overall, our results suggest that (1) an omnivorous predator systemically induces resistance traits in cotton and (2) whereas there is evidence of taxonomic specificity (thrips versus mites), there is little support for trophic specificity (herbivorous thrips versus omnivorous thrips) in the elicitation of induced responses.     

An integrative expression vector for <Emphasis Type="Italic">Actinosynnema pretiosum</Emphasis>

Background  

The Actinomycete Actinosynnema pretiosum ssp. auranticum has commercial importance due to its production of ansamitocin P-3 (AP-3), a potent antitumor agent. One way to increase AP-3 production would be to constitutively express selected genes so as to relieve bottlenecks in the biosynthetic pathway; however, an integrative expression vector for A. pretiosum is lacking. The aim of this study was to construct a vector for heterologous gene expression in A. pretiosum.     

Development and standardization of multiplexed antibody microarrays for use in quantitative proteomics

BACKGROUND: Quantitative proteomics is an emerging field that encompasses multiplexed measurement of many known proteins in groups of experimental samples in order to identify differences between groups. Antibody arrays are a novel technology that is increasingly being used for quantitative proteomics studies due to highly multiplexed content, scalability, matrix flexibility and economy of sample consumption. Key applications of antibody arrays in quantitative proteomics studies are identification of novel diagnostic assays, biomarker discovery in trials of new drugs, and validation of qualitative proteomics discoveries. These applications require performance benchmarking, standardization and specification. RESULTS: Six dual-antibody, sandwich immunoassay arrays that measure 170 serum or plasma proteins were developed and experimental procedures refined in more than thirty quantitative proteomics studies. This report provides detailed information and specification for manufacture, qualification, assay automation, performance, assay validation and data processing for antibody arrays in large scale quantitative proteomics studies. CONCLUSION: The present report describes development of first generation standards for antibody arrays in quantitative proteomics. Specifically, it describes the requirements of a comprehensive validation program to identify and minimize antibody cross reaction under highly multiplexed conditions; provides the rationale for the application of standardized statistical approaches to manage the data output of highly replicated assays; defines design requirements for controls to normalize sample replicate measurements; emphasizes the importance of stringent quality control testing of reagents and antibody microarrays; recommends the use of real-time monitors to evaluate sensitivity, dynamic range and platform precision; and presents survey procedures to reveal the significance of biomarker findings.     

The CD11a partner in Sus scrofa lymphocyte function-associated antigen-1 (LFA-1): mRNA cloning, structure analysis and comparison with mammalian homologues

Background  

Lymphocyte function-associated antigen-1 (LFA-1, CD11a/CD18, alphaLbeta2), the most abundant and widely expressed beta2-integrin, is required for many cellular adhesive interactions during the immune response. Many studies have shown that LFA-1 is centrally involved in the pathogenesis of several diseases caused by Repeats-in-toxin (RTX) -producing bacteria.