Engineering bacteriocin‐mediated resistance against the plant pathogen Pseudomonas syringae

The plant pathogen, Pseudomonas syringae (Ps), together with related Ps species, infects and attacks a wide range of agronomically important crops, including tomato, kiwifruit, pepper, olive and soybean, causing economic losses. Currently, chemicals and introduced resistance genes are used to protect plants against these pathogens but have limited success and may have adverse environmental impacts. Consequently, there is a pressing need to develop alternative strategies to combat bacterial disease in crops. One such strategy involves using narrow‐spectrum protein antibiotics (so‐called bacteriocins), which diverse bacteria use to compete against closely related species. Here, we demonstrate that one bacteriocin, putidacin L1 (PL1), can be expressed in an active form at high levels in Arabidopsis and in Nicotiana benthamiana in planta to provide effective resistance against diverse pathovars of Ps. Furthermore, we find that Ps strains that mutate to acquire tolerance to PL1 lose their O‐antigen, exhibit reduced motility and still cannot induce disease symptoms in PL1‐transgenic Arabidopsis. Our results provide proof‐of‐principle that the transgene‐mediated expression of a bacteriocin in planta can provide effective disease resistance to bacterial pathogens. Thus, the expression of bacteriocins in crops might offer an effective strategy for managing bacterial disease, in the same way that the genetic modification of crops to express insecticidal proteins has proven to be an extremely successful strategy for pest management. Crucially, nearly all genera of bacteria, including many plant pathogenic species, produce bacteriocins, providing an extensive source of these antimicrobial agents.     

Iron,Hepcidin and Inflammatory Status of Young Healthy Overweight and Obese Women in Australia

Background and Aims

Evidence suggests obesity-related inflammation alters iron metabolism potentially increasing the risk of iron deficiency. This cross-sectional study aimed to investigate iron, hepcidin and inflammatory status in young, healthy overweight and obese women.

Methods

114 young (18–25 years), healthy comorbidity-free women with a body mass index (BMI) ≥27.5 kg/m² were recruited. Biochemical data were analysed using mean ± standard deviation or median (interquartile range) and multivariate modelling. Biochemical markers were also stratified according to varying degrees of overweight and obesity.

Results

Anaemia (haemoglobin <120 g/l) and iron deficiency (serum ferritin <15.0 µg/l) were prevalent in 10% and 17% of participants respectively. Mean/median soluble transferrin receptor was 1.61±0.44 mg/l; hepcidin 6.40 (7.85) ng/ml and C-reactive protein (CRP) 3.58 (5.81) mg/l. Multivariate modelling showed that BMI was a significant predictor of serum iron (coefficient = -0.379; standard error = 0.139; p = 0.008), transferrin saturation (coefficient = -0.588; standard error = 0.222; p = 0.009) and CRP (coefficient = 0.127; standard error = 0.024; p<0.001). Stratification of participants according to BMI showed those with ≥35.0 kg/m² had significantly higher CRP (p<0.001) than those in lower BMI categories.

Conclusions

Increasing obesity was associated with minor disturbances in iron metabolism. However, overall outcomes indicated simple iron deficiency (hypoferritinaemia) was the primary iron-related abnormality with no apparent contribution of inflammation or hepcidin, even in those with BMI >35.0 kg/m². This indicates that obesity alone may not be sufficient to induce clinically significant disturbances to iron metabolism as previously described. This may be attributed to the lack of comorbidity in this cohort.     

Sorghum Insect Problems and Management

Sorghum (Sorghum bicolor) has high levels of starch,sugar,and fiber and is one of the most important energy crops in the world.Insect damage is one of the challenges that impacts sorghum biomass production.There are at least 150 insect species that can infest sorghum varieties worldwide.These insects can complete several generations within a growing season,they target various parts of sorghum plants at developmental stages,and they cause significant biomass losses.Genetic research has revealed the existence...     

How integrins control mammary epithelial differentiation: a possible role for the ILK-PINCH-Parvin complex

Differentiation into tissue-specific cell types occurs in response to numerous external signals. Integrins impart signals from the extracellular matrix microenvironment that are required for cell differentiation. However, the precise cytoplasmic transducers of these signals are yet to be understood properly. In lactating mammary epithelial cells, integrin-linked kinase has been identified as an indispensable integrin-signalling adaptor that enables the activation of Rac1, which is necessary for prolactin-induced milk protein expression. Here we use examples from various tissues to summarise possible mechanisms by which ILK and its binding partners PINCH and Parvin (ILK-PINCH-Parvin complex) could be required for Rac activation and mammary epithelial differentiation.     

Supplementary feeding increases Common Buzzard Buteo buteo productivity but only in poor‐quality habitat

Temporal heterogeneity in the effects of food supply during the breeding season on the productivity of the Common Buzzard Buteo buteo was investigated in a supplementary feeding experiment. Pairs were fed artificially (1) before egg‐laying, (2) after chicks hatched and (3) continuously throughout the season, and compared with (4) unfed controls. Pairs fed before egg‐laying had marginally larger clutches than those not fed, but lay date, egg volume and weight, brood size and hatching success were unaffected. Territorial quality had far greater effects, with pairs nesting in low‐quality habitats (bog, scrub and semi‐natural grassland) laying later and having lower hatching success, smaller broods and fewer fledglings than those in more productive agricultural landscapes. Supplementary feeding after egg hatching neutralized the negative effect of poor habitat, resulting in fed birds having significantly more fledglings. This study emphasizes the importance of food availability when provisioning chicks in suboptimal habitats and has implications for the success of diversionary feeding in reducing game losses to Buzzards.     

Synovial membrane protein expression differs between juvenile idiopathic arthritis subtypes in early disease

Introduction

Juvenile idiopathic arthritis (JIA) is the most common rheumatological disease of childhood with a prevalence of around 1 in 1,000. Without appropriate treatment it can have devastating consequences including permanent disability from joint destruction and growth deformities. Disease aetiology remains unknown. Investigation of disease pathology at the level of the synovial membrane is required if we want to begin to understand the disease at the molecular and biochemical level. The synovial membrane proteome from early disease-stage, treatment naive JIA patients was compared between polyarticular and oligoarticular subgroups.

Methods

Protein was extracted from 15 newly diagnosed, treatment naive JIA synovial membrane biopsies and separated by two dimensional fluorescent difference in-gel electrophoresis. Proteins displaying a two-fold or greater change in expression levels between the two subgroups were identified by matrix assisted laser desorption ionization-time of flight mass spectrometry with expression further verified by Western blotting and immunohistochemistry.

Results

Analysis of variance analysis (P ≤ 0.05) revealed 25 protein spots with a two-fold or greater difference in expression levels between polyarticular and oligoarticular patients. Hierarchical cluster analysis with Pearson ranked correlation revealed two distinctive clusters of proteins. Some of the proteins that were differentially expressed included: integrin alpha 2b (P = 0.04); fibrinogen D fragment (P = 0.005); collagen type VI (P = 0.03); fibrinogen gamma chain (P = 0.05) and peroxiredoxin 2 (P = 0.02). The identified proteins are involved in a number of different processes including platelet activation and the coagulation system.

Conclusions

The data indicate distinct synovial membrane proteome profiles between JIA subgroups at an early stage in the disease process. The identified proteins also provide insight into differentially perturbed pathways which could influence pathological events at the joint level.     

An Exploratory Spatial Analysis of ALS Incidence in Ireland over 17.5 Years (1995 – July 2013)

Introduction

There has been much interest in spatial analysis of ALS to identify potential environmental or genetically caused clusters of disease. Results to date have been inconclusive. The Irish ALS register has been recently geocoded, presenting opportunity to perform a spatial analysis on national prospectively gathered data of incident cases over an 18-year period.

Methods

1,645 cases of ALS in Ireland from January 1995 to July 2013 were identified from the Irish ALS register. 1,638 cases were successfully geocoded. Census data from four censuses: 1996, 2002, 2006 & 2011 were used to calculate an average population for the period and standardized incidence rates (SIRs) were calculated for 3,355 areas (Electoral Divisions). Bayesian conditional auto-regression was applied to produce smoothed relative risks (RR). These were then mapped for all cases, males & females separately, and those under 55 vs over 55 at diagnosis. Bayesian and linear regression were used to examine the relationship between population density and RR.

Results

Smoothed maps revealed no overall geographical pattern to ALS incidence in Ireland, although several areas of localized increased risk were identified. Stratified maps also suggested localized areas of increased RR, while dual analysis of the relationship between population density and RR of ALS yielded conflicting results, linear regression revealed a weak relationship.

Discussion

In contrast to some previous studies our analysis did not reveal any large-scale geographic patterns of incidence, yet localized areas of moderately high risk were found in both urban and rural areas. Stratified maps by age revealed a larger number of cases in younger people in the area of County Cork - possibly of genetic cause. Bayesian auto-regression of population density failed to find a significant association with risk, however weighted linear regression of post Bayesian smoothed Risk revealed an association between population density and increased ALS risk.     

Desaturases from the spotted fireworm moth (Choristoneura parallela) shed light on the evolutionary origins of novel moth sex pheromone desaturases

Six acyl-CoA desaturase-encoding cDNAs from mRNA isolated from the spotted fireworm moth, Choristoneura parallela (Lepidoptera: Tortricidae) were characterized and assayed for functionality. The expression levels of these cDNAs were determined in the pheromone gland and fat body by real-time PCR and the resulting patterns are in line with results from published studies on other moth sex pheromone desaturases. The cDNAs were found to correspond to six genes. Using both biochemical and phylogenetic analyses, four of these were found to belong to previously characterized desaturase functional groups [the Delta 10,11, the Delta 9 (16>18) and the Delta 9 (18>16) groups]. A desaturase highly expressed in the pheromone gland was a novel E11 desaturase that was specific to 14-carbon precursor acids. The fifth gene [CpaZ9(14-26)] was found to display a novel Z9 activity indicating that it belongs to a new Delta 9 functional group, whereas the sixth gene was determined to be nonfunctional with respect to desaturase activity. In accordance with previous studies, we find that desaturases of the Delta 10,11 and Delta 14 groups, which are the fastest evolving desaturases and possess the novel pheromone biosynthetic function, are expressed primarily in the pheromone gland whereas all other desaturases, which do not possess the novel reproductive function, evolve more slowly and display the ancestral metabolic function and pattern of gene expression.