Genome‐wide association mapping and biochemical markers reveal that seed ageing and longevity are intricately affected by genetic background and developmental and environmental conditions in barley

Globally, over 7.4 million accessions of crop seeds are stored in gene banks, and conservation of genotypic variation is pivotal for breeding. We combined genetic and biochemical approaches to obtain a broad overview of factors that influence seed storability and ageing in barley (Hordeum vulgare). Seeds from a germplasm collection of 175 genotypes from four continents grown in field plots with different nutrient supply were subjected to two artificial ageing regimes. Genome‐wide association mapping revealed 107 marker trait associations, and hence, genotypic effects on seed ageing. Abiotic and biotic stresses were found to affect seed longevity. To address aspects of abiotic, including oxidative, stress, two major antioxidant groups were analysed. No correlation was found between seed deterioration and the lipid‐soluble tocochromanols, nor with oil, starch and protein contents. Conversely, the water‐soluble glutathione and related thiols were converted to disulphides, indicating a strong shift towards more oxidizing intracellular conditions, in seeds subjected to long‐term dry storage at two temperatures or to two artificial ageing treatments. The data suggest that intracellular pH and (bio)chemical processes leading to seed deterioration were influenced by the type of ageing or storage. Moreover, seed response to ageing or storage treatment appears to be significantly influenced by both maternal environment and genetic background.     

Glutathione S transferase mu polymorphism and gastric cancer in the Portuguese population

The glutathione S-transferases appear to form part of a protective mechanism against the development of cancer where environmental chemical carcinogens are involved. In humans one member of the mu class gene family (GSTM1) has been shown to be polymorphic and is only expressed in ~50% of individuals. Previous studies have shown a possible link between the null phenotype and susceptibility to cancer but have been equivocal regarding stomach cancer. To evaluate any association in Portuguese gastric cancer individuals with GSTM1 variability, we performed GST M 1 polymorphism by PCR amplification in 148 gastric cancer patients and in 84 healthy control individuals. We found no statistical differences between the gastric cancer and control populations (wild type phenotype: 52%, 48%; null phenotype: 48%, 52%, respectively). A subset analysis into site of tumour also revealed no significant differences between the groups, although we found a slight increase of the wild type phenotype in the samples of the antrum compared with the control population (57% vs 48%, respectively; 2= 1.18; p 0.28) and a slight increase of the null phenotype in the signet ring cells/mucocellular group (2= 1.05; p 0.3). However, in both cases it did not reach statistical significance. A subset analysis of the histological groups following the WHO criteria revealed a statistically significant difference (2= 3.704; p 0.05) between the moderately differentiated gastric adenocarcinoma and the presence of the wild type phenotype. These results do not support the hypothesis that the GSTM1 null phenotype predisposes to gastric cancer in the Portuguese population and the moderately differentiated gastric adenocarcinoma seems to be associated with the presence of the G STM 1 wild type phenotype.     

Randomized controlled trial of supported employment in England: 2 year follow-up of the Supported Work and Needs (SWAN) study

Studies from North America have concluded that supported employment using the Individual Placement and Support (IPS) model is effective in helping individuals with severe and persistent mental illness gain competitive employment. The aim of this study was to investigate the effectiveness and cost-effectiveness of IPS in England in patients followed up for 2 years. Patients with severe mental illness were randomised to IPS or local vocational services (treatment as usual). Service use and costs were measured. Two hundred-nineteen participants were randomised, and 86% re-assessed 2 years later. In the multivariate analysis, relatively low rates of competitive employment were found in both the intervention group and the treatment as usual group, although significantly more patients obtained competitive employment in the treatment arm (22% vs. 11%, p=0.041). There were no significant differences in costs. The employment rate among participants receiving IPS was lower than in previously published reports, and the number needed to treat to obtain the benefit of IPS was relatively high. This may reflect difficulties in the implementation of IPS where it is not structurally integrated within mental health teams, as well as economic disincentives which lead to lower levels of motivation for patients and mental health professionals.     

Effect of Low Salt Concentrations on Nitrate Reductase and Peroxidase of Sugar Beet Leaves

Nitrate reductase, peroxidase, nitrate and sugar contents ofsugar beet leaves were increased by low NaCl concentrations.The salt was applied in the nutrient solution at concentrationsof 2, 4 and 10 mM and determinations were made at 24, 48, 72and 96 h after salt applications. Nitrate reductase was assayed both in vitro and in vivo. Inthe latter case maximum activity was attained in the first 24h for all salt concentrations after which there was a declineuntil control level was reached. Maximum nitrate content wasobserved at 48 h. It is suggested that in the first hours thesalt stimulated preferentially the flux of nitrate into theinducer nitrate pool. Maximum sugar content occurred in thefirst 24 h. This may be associated with the increase in nitratereductase activity as sugars are a source of reducing powerfor the enzyme and can supply energy and carbon skeletons forthe induction process. The salt treatments also stimulated peroxidase, maximum activitybeing reached at 48 h. Key words: Sugar beet, Sodium chloride, Nitrate reductase, Peroxidase