Induced plant volatiles allow sensitive monitoring of plant health status in greenhouses

A novel approach to support the inspection of greenhouse crops is based on the measurement of volatile organic compounds emitted by unhealthy plants.This approach has attracted some serious interest over the last decade. In pursuit of this interest, we performed several experiments at the laboratory-scale to pinpoint marker volatiles that can be used to indicate certain health problems. In addition to these laboratory experiments, pilot and model studies were performed in order to verify the validity of these marker volatiles under real-world conditions. This paper provides an overview of results and gives an outlook on the use of plant volatiles for plant health monitoring.Key words: plant health, volatiles, plant pathogens, plant infection     

Effect of man-made electromagnetic fields on common <i>Brassicaceae Lepidium sativum</i> (cress d’Alinois) seed germination: a preliminary replication study

Under high levels of radiation (70-100 µW/m2 =175 mV/m), seeds of Brassicaceae Lepidium sativum (cress d’Alinois) never germinated. In fact, the first step of seeds’ germination ‒ e.g. imbibitions of germinal cells ‒ could not occur under radiation, while inside the humid compost such imbibitions occurred and roots slightly developed. When removed from the electromagnetic field, seeds germinated normally. The radiation was, thus, most likely the cause of the non-occurrence of the seeds’ imbibitions and germination.     

Arbuscular mycorrhizal fungal diversity in high-altitude hypersaline Andean wetlands studied by 454-sequencing and morphological approaches

Withania somnifera, also known as Indian ginseng is known to contain valuable bioactive compounds, called withanolides that structurally resemble ginsenosides of Panax ginseng. These compounds provide the basis of pharmacological relevance in traditional systems of medicine. In the present study, 150 hairy root lines of W. somnifera were induced of which nine fast growing lines were analysed for their growth and withanolide content. Hairy root line W9 was selected due to its high specific growth rate (0.196 ± 0.005 d^?1) and high withanolide content. The response to different concentrations of elicitors (methyl jasmonate and P. indica cell homogenate) and various exposure durations was assessed in the W9 hairy root line. The withanolide content as well as the pattern of gene expression from MVA, MEP and sterol pathway, was evaluated using qPCR. Though gene expression and withanolide content were found to be elevated in almost all MeJ and CHP treatments, the exposure of hairy roots to 15 μM MeJ for 4 h gave the maximum withanolide yield. The results suggest that the elicitation potential of methyl jasmonate was higher than that of P. indica cell homogenate for increasing withanolide levels in hairy roots of W. somnifera.     

Proteomics characterization of outer membrane vesicles from the extraintestinal pathogenic Escherichia coli DeltatolR IHE3034 mutant

Extraintestinal pathogenic Escherichia coli are the cause of a diverse spectrum of invasive infections in humans and animals, leading to urinary tract infections, meningitis, or septicemia. In this study, we focused our attention on the identification of the outer membrane proteins of the pathogen in consideration of their important biological role and of their use as potential targets for prophylactic and therapeutic interventions. To this aim, we generated a DeltatolR mutant of the pathogenic IHE3034 strain that spontaneously released a large quantity of outer membrane vesicles in the culture supernatant. The vesicles were analyzed by two-dimensional electrophoresis coupled to mass spectrometry. The analysis led to the identification of 100 proteins, most of which are localized to the outer membrane and periplasmic compartments. Interestingly based on the genome sequences available in the current public database, seven of the identified proteins appear to be specific for pathogenic E. coli and enteric bacteria and therefore are potential targets for vaccine and drug development. Finally we demonstrated that the cytolethal distending toxin, a toxin exclusively produced by pathogenic bacteria, is released in association with the vesicles, supporting the recently proposed role of bacterial vesicles in toxin delivery to host cells. Overall, our data demonstrated that outer membrane vesicles represent an ideal tool to study Gram-negative periplasm and outer membrane compartments and to shed light on new mechanisms of bacterial pathogenesis.     

Cytoplasmic dynein could be key to understanding neurodegeneration

A new mouse mutation, Sprawling, highlights an essential role for the dynein heavy chain in sensory neuron function, but it lacks the ability of other known heavy-chain mutations to ameliorate neurodegeneration due to defective superoxide dismutase.