Interactions between root and shoot herbivores of Ammophila arenaria in the laboratory do not translate into correlated abundances in the field

Over the past decades a growing body of literature has presented proof of the possible interactions between foliar and root herbivores. These effects can be positive, negative or neutral in either direction, depending on the species and the involved mechanism. Most of these studies however concern experiments under controlled conditions. Whether these interactions affect the distribution of herbivores under natural conditions still largely remains an open question. This study examined interactions between root feeding nematodes and shoot feeding aphids on Ammophila arenaria in the laboratory. We subsequently addressed the question whether expectations from this experiment are reflected in correlations between plant related variables and the abundance of both herbivores in the field. We demonstrated that nematodes and aphids can negatively affect each other in a controlled microcosm. In the field however no significant correlations between nematode and aphid abundances could be detected. There, shorter plants with a more vital leaf set and a higher root density supported the highest numbers of aphids. Plants with a lower root density and higher root vitality held more migratory endoparasitic nematodes, while more nematode cysts were found among roots with a low vitality. A certain plant property can furthermore affect above‐ and belowground herbivores in the opposite direction, such as root density in this case. This study suggests that effects of root herbivores on foliar herbivores or vice versa seem to be blurred in a field situation where other variables related to plant vitality and water content structure the herbivore populations. Therefore, caution should be used in generalising the prevalence of these interactions between the above‐ and belowground fauna, based solely on laboratory experiments.     

Dual-color superresolution microscopy reveals nanoscale organization of mechanosensory podosomes

Podosomes are multimolecular mechanosensory assemblies that coordinate mesenchymal migration of tissue-resident dendritic cells. They have a protrusive actin core and an adhesive ring of integrins and adaptor proteins, such as talin and vinculin. We recently demonstrated that core actin oscillations correlate with intensity fluctuations of vinculin but not talin, suggesting different molecular rearrangements for these components. Detailed information on the mutual localization of core and ring components at the nanoscale is lacking. By dual-color direct stochastic optical reconstruction microscopy, we for the first time determined the nanoscale organization of individual podosomes and their spatial arrangement within large clusters formed at the cell–substrate interface. Superresolution imaging of three ring components with respect to actin revealed that the cores are interconnected and linked to the ventral membrane by radiating actin filaments. In core-free areas, αMβ2 integrin and talin islets are homogeneously distributed, whereas vinculin preferentially localizes proximal to the core and along the radiating actin filaments. Podosome clusters appear as self-organized contact areas, where mechanical cues might be efficiently transduced and redistributed. Our findings call for a reevaluation of the current “core–ring” model and provide a novel structural framework for further understanding the collective behavior of podosome clusters.     

The Possibility of Meeting Greenhouse Energy and CO<Subscript>2</Subscript> Demands Through Utilisation of Cucumber and Tomato Residues

The article examines the possibility of using residues from greenhouse cucumber and tomato cultivation as biomass for energy and CO₂ production in order to meet greenhouse needs. Methane fermentation and combustion were compared. Moreover, the legitimacy of ensiling as a storage method for biogas plant was evaluated. The tested waste was found to be an unsuitable feedstock for the production of silage due to low sugar and high protein content. Fresh waste had a higher biogas yield than silage; however, its fermentation lasted longer. Furthermore, the results showed that, in the case of fresh residues, the methane fermentation proved to be a more energy-efficient process, while air-dry biomass is a more sustainable feedstock for combustion. The energy and CO₂ balance showed that, regardless of the method used, the available quantity of waste is too small to meet the greenhouse needs.     

Larger direct than indirect effects of multiple environmental changes on leaf nitrogen of forest herbs

Plant and Soil - Shrub encroachment has profound influences on regional carbon cycling. However, few studies have examined the changes in soil organic carbon (SOC) components at the molecular level...     

Solid-phase synthesis of peptidosulfonamide containing peptides derived from Leu-enkephalin

Using Boc or Fmoc-protected β-substituted aminoethanesulfonyl chlorides (2-substituted taurylchlorides) the solid-phase synthesis of dipeptidosulfonamides as well as peptidosulfonamide containing peptides derived from Leu-enkephalin is described. The binding activity of the peptidosulfonamide YGGFL derivatives is reported.