Effect of short-term exposure to high-temperature on total gene expression in the leaves of four raspberry (Rubus idaeus L.) cultivars

Summary

The effect of high temperature stress (27ºC or 37ºC for 24 h) on total gene expression profiles in the annual-fruiting raspberry (Rubus idaeus L.) cultivars ‘Autumn Bliss’, ‘Autumn Treasure’, ‘Erika’, and ‘Polka’ were evaluated at the floral initiation stage using a customised Rubus microarray. Significantly affected genes were obtained by pairwise t-tests using ‘volcano plots’ for each cultivar × treatment. A 10ºC elevation in temperature altered levels of expression, in at least one cultivar, of 644 differentially expressed genes in total, with ‘Erika’ and ‘Autumn Treasure’ showing elevated expression of 38 genes compared to ‘Autumn Bliss’ and ‘Polka’. We identified 12 common candidate genes that were modulated differentially in ‘Autumn Bliss’ and ‘Erika’ at 37ºC compared to 27ºC. In addition, two aquaporin genes (PIP1 and TIP2) were down-regulated in ‘Autumn Bliss’, but up-regulated in ‘Autumn Treasure’, ‘Polka’, and ‘Erika’ at 37ºC. Other down-regulated genes from the list of 38 genes included those encoding major latex-like proteins, plasma membrane proteins, cysteine rich proteins, and other stress-related proteins. Validation by real-time quantitative RT-PCR (RT-qPCR) indicated subtle changes in differential gene expression, suggesting a mild response to heat stress. This study used molecular tools to increase our understanding of, and to identify candidate genes involved in, the heat stress response of four annual-fruiting raspberry cultivars.     

Over-seasons analysis of quantitative trait loci affecting phenolic content and antioxidant capacity in raspberry

This study examined the total phenol content (TPC) and total anthocyanin content (TAC) in ripe fruit of progeny of a mapping population generated from a cross between the European red raspberry cv. Glen Moy ( Rubus ideaus var. idaeus) and the North American red raspberry cv. Latham ( Rubus ideaus var. strigosus) over five seasons in two different growing environments. Measurements of antioxidant capacity (FRAP and TEAC) were also carried out. TPC was highly correlated with TEAC and FRAP across the entire data set. The subset of anthocyanin content was genotype-dependent but also correlated with TPC, although the proportion of anthocyanin compounds varied between progeny. Quantitative trait locus (QTL) analysis was carried out, and key markers were tested for consistency of effects over sites and years. Four regions, on linkage groups 2, 3, 5, and 6, were identified. These agree with QTLs from a previous study over a single season and indicate that QTL effects were robust over seasons.     

Elemental Speciation and Distribution in Sediments of a Eutrophied Subtropical Freshwater Reservoir Using Postextraction Normalisation

The speciation and distribution of trace and major elements (Al, As, Cd, Cr, Cu, Fe, Mn, Ni, P, Pb and Zn) in the sediments of Emigrant Creek Dam (ECD), New South Wales Australia were investigated using sequential extraction, postextraction normalisation and spatial mapping to indicate source and dispersion patterns. Subsurface coring provided an estimate of elemental enrichment and showed that As 1.9?>?P 1.7?>?N 1.5????Cd 1.5?>?Mn 1.3 were enriched. Moreover, a high proportion of the enriched elements (mean 57, 34, 47 and 87?% for As, P, Cd and Mn, respectively) were assessed as being bioavailable. Comparisons with ISQGs found that sediments from sites in proximity to Emigrant Creek inflows had the highest accumulations of metals and the greatest potential for causing biological harm. Spatially, contaminants accumulate in ECD sediments adjacent to anthropogenic sources including a cattle dip site, dredged sediment and macrophyte dump areas, and agricultural/residential runoff. Moreover, the integrated technique and postextraction normalisation allow assessment of texturally diverse and difficult sediments.     

Diagnosis of botulism types C and D in cattle by a monoclonal antibody-based sandwich ELISA

This study was undertaken to evaluate two monoclonal antibody-based sandwich ELISAs (sELISAs) for the detection of Clostridium botulinum neurotoxins (BoNTs) types C and D from culture-enriched intestinal content samples from cattle. To validate the diagnostic significance of the presence of cultivable, toxin-producing C botulinum in the intestines of cattle, samples from both suspect and non-suspect botulism cases were examined. BoNT was detected by both sELISAs in a greater number of suspect animals than by direct testing of uncultured samples by mouse bioassay. One sELISA detected two BoNT C and one BoNT Group III mosaic isoform in three animals that were missed by the other, and both sELISAs failed to identify samples from two mouse bioassay-positive BoNT C animals. BoNT D was also detected in one non-suspect sample by one of the sELISAs.     

Treatment of cattle with DNA-encoded Flt3L and GM-CSF prior to immunization with Theileria parva candidate vaccine antigens induces CD4 and CD8 T cell IFN-γ responses but not CTL responses

Theileria parva antigens recognized by cytotoxic T lymphocytes (CTLs) are prime vaccine candidates against East Coast fever in cattle. A strategy for enhancing induction of parasite-specific T cell responses by increasing recruitment and activation of dendritic cells (DCs) at the immunization site by administration of bovine Flt3L and GM-CSF prior to inoculation with DNA vaccine constructs and MVA boost was evaluated. Analysis of immune responses showed induction of significant T. parva-specific proliferation, and IFN-γ-secreting CD4(+) and CD8(+) T cell responses in immunized cattle. However, antigen-specific CTLs were not detected. Following lethal challenge, 5/12 immunized cattle survived by day 21, whereas all the negative controls had to be euthanized due to severe disease, indicating a protective effect of the vaccine (p<0.05). The study demonstrated the potential of this technology to elicit significant MHC class II and class I restricted IFN-γ-secreting CD4(+) and CD8(+) T cells to defined vaccine candidate antigens in a natural host, but also underscores the need to improve strategies for eliciting protective CTL responses.