Multidisciplinary Approach to Unravelling the Relative Contribution of Different Oxylipins in Indirect Defense of Arabidopsis thaliana

The oxylipin pathway is commonly involved in induced plant defenses, and is the main signal-transduction pathway induced by insect folivory. Herbivory induces the production of several oxylipins, and consequently alters the so-called ‘oxylipin signature’ in the plant. Jasmonic acid (JA), as well as pathway intermediates are known to induce plant defenses. Indirect defense against herbivorous insects comprises the production of herbivore-induced plant volatiles (HIPVs). To unravel the precise oxylipin signal-transduction underlying the production of HIPVs in Arabidopsis thaliana and the resulting attraction of parasitoid wasps, we used a multidisciplinary approach that includes molecular genetics, metabolite analysis, and behavioral analysis. Mutant plants affected in the jasmonate pathway (18:0 and/or 16:0 -oxylipin routes; mutants dde2-2, fad5, opr3) were studied to assess the effects of JA and its oxylipin intermediates 12-oxo-phytodienoate (OPDA) and dinor-OPDA (dnOPDA) on HIPV emission and parasitoid (Diadegma semiclausum) attraction. Interference with the production of the oxylipins JA and OPDA altered the emission of HIPVs, in particular terpenoids and the phenylpropanoid methyl salicylate, which affected parasitoid attraction. Our data show that the herbivore-induced attraction of parasitoid wasps to Arabidopsis plants depends on HIPVs that are induced through the 18:0 oxylipin-derivative JA. Furthermore, our study shows that the 16:0-oxylipin route towards dnOPDA does not play a role in HIPV induction, and that the role of 18:0 derived oxylipin-intermediates, such as OPDA, is either absent or limited

The Worker Honeybee Fat Body Proteome Is Extensively Remodeled Preceding a Major Life-History Transition

Honeybee workers are essentially sterile female helpers that make up the majority of individuals in a colony. Workers display a marked change in physiology when they transition from in-nest tasks to foraging. Recent technological advances have made it possible to unravel the metabolic modifications associated with this transition. Previous studies have revealed extensive remodeling of brain, thorax, and hypopharyngeal gland biochemistry. However, data on changes in the abdomen is scarce. To narrow this gap we investigated the proteomic composition of abdominal tissue in the days typically preceding the onset of foraging in honeybee workers

C-reactive protein point of care testing and physician communication skills training for lower respiratory tract infections in general practice: economic evaluation of a cluster randomized trial.

RATIONALE, AIMS AND OBJECTIVES: An economic evaluation of general practitioner (GP) use of C-reactive protein (CRP) point of care test, GP communication skills training, and both GP use of CRP and communication skills training on antibiotic use for lower respiratory tract infections (LRTIs) in general practice. METHODS: Cost-effectiveness analysis with a time horizon of 28 days alongside a factorial, cluster randomized trial in 431 patients with LRTIs recruited by 40 GPs. INTERVENTIONS: usual care (control group), GP use of CRP point of care test, GP communication skills training, and both CRP use and communication skills training. MAIN OUTCOME MEASURE: health care costs. Cost-effectiveness, using the primary outcome measure antibiotic prescribing at index consultation, was assessed by incremental cost-effectiveness ratios (ICER). To adjust for skewed data and clustering, we used non-parametric bootstrapping re-sampling to derive percentile intervals for the mean difference in total costs and the mean difference in effectiveness between the groups. Various implementation scenarios according to GP preference were modelled with corresponding net monetary benefit (NMB) curves based on a given willingness-to-pay (λ) for a 1% lower antibiotic prescribing rate. RESULTS: The total mean cost per patient in the usual care group was €35.96 with antibiotic prescribing of 68%, €37.58 per patient managed by GPs using CRP tests (antibiotic prescribing 39%, ICER €5.79), €25.61 per patient managed by GPs trained in enhanced communication skills (antibiotic prescribing 33%, dominant) and €37.78 per patient managed by GPs using both interventions (antibiotic prescribing 23%, ICER €4.15). The interventions are cost-effective in any combination (yielding NMB at no willingness-to-pay), taking into account GPs' preferences where at least 15% of GPs chose to implement the communication skills training. CONCLUSIONS: The two strategies, both singly and combined, are cost-effective interventions to reduce antibiotic prescribing for LRTI, at no, or low willingness-to-pay. Taking GP preferences into account will optimize investment in strategies to reduce antibiotic prescribing for LRTI