9,10-KODA, an α-ketol produced by the tonoplast-localized 9-lipoxygenase ZmLOX5, plays a signaling role in maize defense against insect herbivory

13-Lipoxygenases (LOXs) initiate the synthesis of jasmonic acid (JA), the best-understood oxylipin hormone in herbivory defense. However, the roles of 9-LOX-derived oxylipins in insect resistance remain unclear. Here, we report a novel anti-herbivory mechanism mediated by a tonoplast-localized 9-LOX, ZmLOX5, and its linolenic acid-derived product, 9-hydroxy-10-oxo-12(Z),15(Z)-octadecadienoic acid (9,10-KODA). Transposon-insertional disruption of ZmLOX5 resulted in the loss of resistance to insect herbivory. lox5 knockout mutants displayed greatly reduced wound-induced accumulation of multiple oxylipins and defense metabolites, including benzoxazinoids, abscisic acid (ABA), and JA-isoleucine (JA-Ile). However, exogenous JA-Ile failed to rescue insect defense in lox5 mutants, while applications of 1 μM 9,10-KODA or the JA precursor, 12-oxo-phytodienoic acid (12-OPDA), restored wild-type resistance levels. Metabolite profiling revealed that exogenous 9,10-KODA primed the plants for increased production of ABA and 12-OPDA, but not JA-Ile. While none of the 9-oxylipins were able to rescue JA-Ile induction, the lox5 mutant accumulated lower wound-induced levels of Ca2+, suggesting this as a potential explanation for lower wound-induced JA. Seedlings pretreated with 9,10-KODA exhibited rapid or more robust wound-induced defense gene expression. In addition, an artificial diet supplemented with 9,10-KODA arrested fall armyworm larvae growth. Finally, analysis of single and double lox5 and lox10 mutants showed that ZmLOX5 also contributed to insect defense by modulating ZmLOX10-mediated green leaf volatile signaling. Collectively, our study uncovered a previously unknown anti-herbivore defense and hormone-like signaling activity for a major 9-oxylipin α-ketol.

"Always Events® "… just another quality improvement tool … or is it?

INTRODUCTION

Always Events® are defined as "those aspects of the care experience that should always occur when patients, their family members or other care partners, and service users interact with health care professionals and the health care system". It is a quality improvement methodology that starts by asking our patients the simple question "what matters to you?" and then through coproduction, works out a way to achieve this.

METHODS AND RESULTS

This article tells our story and highlights the value of undertaking an Always Event® within the Radiology department at Warrington and Halton Hospitals. It will demonstrate how this approach combines research, an evaluation of findings and implementation of those findings within a very short timeframe. Embedded within the article are comments from our staff, volunteers and patients which reflect upon their experiences, our limitations, the outcomes we achieved and the impact it has had upon our patients and staff.

CONCLUSION AND IMPLICATIONS FOR PRACTICE

It was important to our patients that they would be informed of how long they would wait for their examination once they booked in at x-ray reception. By undertaking an Always Event® this process is now embedded in our departments everyday activities with over 90% of our patients now being informed of their waiting time. This continued collaboration has really emphasised the value of listening to our patients, and the benefits this can lead to. It has also encouraged a positive research culture within our department (optimisation studies, working with industry, quality projects), helping to progress our profession and resulting in a quality service for our patients.

Purification and characterization of Arabidopsis thaliana oligosaccharyltransferase complexes from the native host: a protein super-expression system for structural studies

The oligosaccharyltransferase (OT) complex catalyzes N-glycosylation of nascent secretory polypeptides in the lumen of the endoplasmic reticulum. Despite their importance, little is known about the structure and function of plant OT complexes, mainly due to lack of efficient recombinant protein production systems suitable for studies on large plant protein complexes. Here, we purified Arabidopsis OT complexes using the tandem affinity-tagged OT subunit STAUROSPORINE AND TEMPERATURE SENSITIVE3a (STT3a) expressed by an Arabidopsis protein super-expression platform. Mass-spectrometry analysis of the purified complexes identified three essential OT subunits, OLIGOSACCHARYLTRANSFERASE1 (OST1), HAPLESS6 (HAP6), DEFECTIVE GLYCOSYLATION1 (DGL1), and a number of ribosomal subunits. Transmission-electron microscopy showed that STT3a becomes incorporated into OT-ribosome super-complexes formed in vivo, demonstrating that this expression/purification platform is suitable for analysis of large protein complexes. Pairwise in planta interaction analyses of individual OT subunits demonstrated that all subunits identified in animal OT complexes are conserved in Arabidopsis and physically interact with STT3a. Genetic analysis of newly established OT subunit mutants for OST1 and DEFENDER AGAINST APOTOTIC DEATH (DAD) family genes revealed that OST1 and DAD1/2 subunits are essential for the plant life cycle. However, mutations in these individual isoforms produced much milder growth/underglycosylation phenotypes than previously reported for mutations in DGL1, OST3/6 and STT3a.

Improved recombinant protein production in Arabidopsis thaliana

Production and isolation of recombinant proteins are key steps in modern Molecular Biology. Expression vectors and platforms for various hosts, including both prokaryotic and eukaryotic systems, have been used. In basic plant research, Arabidopsis thaliana is the central model for which a wealth of genetic and genomic resources is available, and enormous knowledge has been accumulated over the past years - especially since elucidation of its genome in 2000. However, until recently an Arabidopsis platform had been lacking for preparative-scale production of homologous recombinant proteins. We recently established an Arabidopsis-based super-expression system, and used it for a structural pilot study of a multi-subunit integral membrane protein complex. This review summarizes the benefits and further potential of the model plant system for protein productions.

ABBREVIATIONS

Nb, Nicotiana benthamiana; OT, oligosaccharyltransferase.

Use of serum biomarkers in a diagnostic test for irritable bowel syndrome

BACKGROUND

Currently, no single serum biomarker can reliably differentiate irritable bowel syndrome (IBS) from other functional gastrointestinal disorders or organic diseases of the gastrointestinal tract.

AIM

To develop and validate a diagnostic test using serum biomarkers to detect IBS.

METHODS

Ten serum biomarkers were selected from a potential panel of 140 for their ability to differentiate IBS from non-IBS disease in blood samples from patients with IBS, other gastrointestinal disorders and healthy volunteers. A predictive modelling tool was developed to assess patterns and relationships among the 10 serum biomarkers that best differentiated IBS patients from healthy controls and patients with non-IBS gastrointestinal disease. This model was tested in a different cohort of patients and healthy controls (n = 516) to determine the predictive accuracy of differentiating IBS from non-IBS.

RESULTS

The sensitivity and specificity of the 10-biomarker algorithm for differentiating IBS from non-IBS was 50% and 88% respectively. The positive predictive value was 81%, and the negative predictive value was 64% at 50% IBS prevalence in the validation cohort. Overall accuracy was 70%.

CONCLUSIONS

Assessing serum biomarker patterns can differentiate IBS from non-IBS with reasonable sensitivity and specificity. Assessing serum biomarkers in an overall diagnostic strategy may allow earlier diagnosis and treatment for patients with IBS.

Reperfusion-induced leukocyte adhesion and vascular protein leakage in normal and hypercholesterolemic rats

The objective of this study was to define the influence of hypercholesterolemia on ischemia-reperfusion (I/R)-induced leukocyte-endothelial cell adhesion and albumin leakage in rat mesenteric venules. The microvascular alterations normally elicited by I/R (leukocyte adherence and emigration, albumin leakage, and platelet aggregation) were more pronounced in hypercholesterolemic rats (compared with control rats). Monoclonal antibodies against the adhesion glycoproteins CD11/CD18 and intercellular adhesion molecule-1 attenuated the I/R-induced leukocyte adherence and emigration and albumin leakage. Leukocyte adherence, but not albumin leakage, was diminished in animals pretreated with a P-selectin-specific antibody. Platelet aggregation was reduced by antibodies directed against either P-selectin, CD18, or intercellular adhesion molecule-1, as well as a GPIIb-IIIa antagonist. These results indicate that the enhanced reperfusion-induced albumin leakage in hypercholesterolemic rats is dependent on leukocyte-endothelial cell adhesion. Furthermore, P-selectin- and CD11/CD18-dependent heterotypic and GPIIb-IIIa-mediated homotypic platelet aggregation appear to influence the extravasation of both leukocytes and albumin in postischemic venules of hypercholesterolemic rats.