Effects of food quality on trade‐offs among growth,immunity and survival in the greater wax moth Galleria mellonella

The resources available to an individual in any given environment are finite, and variation in life history traits reflect differential allocation of these resources to competing life functions. Nutritional quality of food is of particular importance in these life history decisions. In this study, we tested trade‐offs among growth, immunity and survival in 3 groups of greater wax moth (Galleria mellonella) larvae fed on diets of high and average nutritional quality. We found rapid growth and weak immunity (as measured by encapsulation response) in the larvae of the high‐energy food group. It took longer to develop on food of average nutritional quality. However, encapsulation response was stronger in this group. The larvae grew longer in the low‐energy food group, and had the strongest encapsulation response. We observed the highest survival rates in larvae of the low‐energy food group, while the highest mortality rates were observed in the high‐energy food group. A significant negative correlation between body mass and the strength of encapsulation response was found only in the high‐energy food group revealing significant competition between growth and immunity only at the highest rates of growth. The results of this study help to establish relationships between types of food, its nutritional value and life history traits of G. mellonella larvae.     

Characterization of a <Emphasis Type="Italic">Pinus sylvestris</Emphasis> thaumatin-like protein gene and determination of antimicrobial activity of the in vitro expressed protein

Thaumatin-like proteins (TLPs) are pathogenesis-related proteins, which are involved in plant defense responses to pathogen infection. Expression of the Pinus sylvestris L. TLP gene is up-regulated by methyl jasmonate treatment and inoculation with Heterobasidion annosum. A full-length Pinus taeda TLP gene sequence was used to design PCR primers for amplification of the full-length TLP gene from P. sylvestris. A putative 705-bp open reading frame of TLP gene was cloned into Escherichia coli cells, and then subcloned into the overexpression vector pET100 using BL21 Star expression bacteria. Optimization of the expression of recombinant TLP was achieved by decreasing both expression temperature and IPTG concentration. The purified 24.6-kDa TLP shows antimicrobial activity against 12 fungal species.     

NMR-based metabolomics using earthworms as potential indicators for soil health

Soil health is key for sustainable productivity and adaptation to climate change. Agricultural practice can significantly impact on soil health. The aim of this study was to examine the effect of two land management regimes on organisms (earthworms) that may be used as indicators for soil health via NMR metabolomics. Earthworms are important in the soil decomposition process and viewed as a sentinel species in soil. The presence/absence of earthworm species and their relative abundances provide a gross indication of the health of the soil and it is expected that land use would affect earthworm metabolism as the populations rose or declined in response to changing soil health parameters. In order to test this hypothesis metabolomics approaches were employed to determine if biological indicators of soil change can be detected. Two species of earthworms, an unidentified native species and the European species Aporrectodea caliginosa, were collected from properties in Victoria, Australia where the land was treated with either biological (organic) or conventional (chemical) treatment regimes. Both lipid and aqueous NMR metabolomics for earthworms was employed, demonstrating that class classifications can be achieved with both datasets and provide orthogonal, complementary, chemical information. The study indicates that land-use has a measurable effect on the biochemistry of worm populations. Potential biomarkers of land use and worm stress were found, including elevated levels of glucose, maltose, alanine and triacylglycerides. This study demonstrates the utility of NMR metabolomics approaches in detecting biomarkers related to land treatment regimes and potentially soil health attributes. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.