Warm and dry weather accelerates and elongates <Emphasis Type="Italic">Cladosporium</Emphasis> spore seasons in Poland

Temperature is the environmental factor that systematically changes for decades and, as in plants and animals, can significantly affect the growth and development of fungi, including the abundance of their sporulation. During the time of study (2010–2012), a rapid increase in air temperature was observed in Poland, which coincided with the substantial decrease in rainfall. The increase in annual mean temperatures at three monitoring sites of this study was 0.9 °C in Lublin and Rzeszow (east Poland) and 2.0 °C in Poznan (west Poland). Such warming of air masses was comparable to the average global air temperature rise in the period of 1880–2012 accounting for 0.85 °C, as reported by the Intergovernmental Panel on Climate Change. Moreover, there was a substantial decrease in rainfall, ranging from 32.7 % (Poznan) to 43.0 % (Rzeszow). We have demonstrated that under such conditions the mean and median values of total Cladosporium spore counts significantly increased and the spore seasons were greatly accelerated. Moreover, earlier start and later end of the season caused its extension, lasting from over 20 days in Rzeszow to around 60 days in Lublin and Poznan, when the cumulative amount of 5–95 % of spores was considered. The time of reaching the cumulative amount of 50 % of spores was up to 25 days earlier (difference in Poznan between 2010 and 2012). There was also a striking acceleration of the date of the maximal Cladosporium spore concentration per cubic metre of air (26 days for Lublin, 43 for Poznan and 56 for Rzeszow).     

Soil application of Beauveria bassiana GHA against apple sawfly,Hoplocampa testudinea (Hymenoptera: Tenthredinidae): Field mortality and fungal persistence

Low impact alternatives to synthetic insecticides for the control of apple sawfly (Hoplocampa testudinea Klug) are scarce encumbering pest management in organic apple orchards. We investigated the soil persistence and field efficacy of the entomopathogenic fungus Beauveria bassiana (Balsamo) Vuillemin (BotaniGard) against apple sawfly under common organic orchard practices. We also assessed the efficacy of B. bassiana GHA and Metarhizium brunneum Petch (indigenous strain) against sawfly in the laboratory. Larvae treated with either fungus in the laboratory died faster than control larvae and displayed 49.4%–68.4% mycosis. In the field, B. bassiana density remained high in the week after application, during larval descent to the soil. Fungal density decreased to 25% at 49 d after application and to 0.4% after 55 weeks. Molecular markers revealed that the majority of fungal isolates recovered comprised the applied B. bassiana strain GHA. Larvae pupating in soil cages in the orchard for 49 d displayed 17% mycosis. The high efficacy under laboratory conditions was not seen in the field. B. bassiana application resulted in densities above the upper natural background level during the growing season, but reversion to background levels occurred within a year. It remains to be investigated whether this has a detrimental effect on nontarget organisms. Additional work is needed to bridge the knowledge gap between laboratory and field efficacy in orchards.     

Bacteriophages engineered to display foreign peptides may become short-circulating phages

Bacteriophages draw scientific attention in medicine and biotechnology, including phage engineering, widely used to shape biological properties of bacteriophages. We developed engineered T4-derived bacteriophages presenting seven types of tissue-homing peptides. We evaluated phage accumulation in targeted tissues, spleen, liver and phage circulation in blood (in mice). Contrary to expectations, accumulation of engineered bacteriophages in targeted organs was not observed, but instead, three engineered phages achieved tissue titres up to 2 orders of magnitude lower than unmodified T4. This correlated with impaired survival of these phages in the circulation. Thus, engineering of T4 phage resulted in the short-circulating phage phenotype. We found that the complement system inactivated engineered phages significantly more strongly than unmodified T4, while no significant differences in phages’ susceptibility to phagocytosis or immunogenicity were found. The short-circulating phage phenotype of the engineered phages suggests that natural phages, at least those propagating on commensal bacteria of animals and humans, are naturally optimized to escape rapid neutralization by the immune system. In this way, phages remain active for longer when inside mammalian bodies, thus increasing their chance of propagating on commensal bacteria. The effect of phage engineering on phage pharmacokinetics should be considered in phage design for medical purposes.     

Expression of a glycosylated GFP as a bivalent reporter in exocytosis

The complex-type N-linked glycans of plants differ markedly in structure from those of animals. Like those of insects and mollusks they lack terminal sialic acid(s) and may contain an α-(1,3)-fucose (Fuc) linked to the proximal GlcNAc residue and/or a β-(1,2)-xylose (Xyl) residue attached to the proximal mannose (Man) of the glycan core. N-glycosylated GFPs were used in previous studies showing their effective use to report on membrane traffic between the ER and the Golgi apparatus in plant cells. In all these cases glycosylated tags were added at the GFP termini. Because of the position of the tag and depending on the sorting and accumulation site of these modified GFP, there is always a risk of processing and degradation, and this protein design cannot be considered ideal. Here, we describe the development of three different GFPs in which the glycosylation site is internally localized at positions 80, 133, or 172 in the internal sequence. The best glycosylation site was at position 133. This glycosylated GFPgl133 appears to be protected from undesired processing of the glycosylation site and represents a bivalent reporter for biochemical and microscopic studies. After experimental validation, we can conclude that amino acid 133 is an effective glycosylation site and that the GFPgl133 is a powerful tool for in vivo investigations in plant cell biology.     

Tattoo and piercing as signals of biological quality

Tattoos and non-conventional piercings are used in many societies. There are several social reasons for which people use these forms of body decorations (e.g., marking social status or signaling membership within a subculture). However, it is interesting why only some people within a group that uses body decoration as a badge of membership decide upon such decorations. Since both tattoos and piercings can present health risks (e.g., due to blood-borne disease transmission risk), we postulate that people who decide to have such a body decoration might have relatively higher biological quality and that tattoos/piercings can be an honest signal of genetic quality. The possible opposite hypothesis is the “attractiveness increase hypothesis,” according to which people use body decorations to increase their own physical attractiveness or to hide some shortcomings in their appearance (e.g., low body symmetry). To test these hypotheses, we compared body fluctuating asymmetry, which is considered a good measure of developmental stability, between individuals wearing tattoos and/or non-conventional piercings (n=116) and a control group (without such body decorations) (n=86). We found that majority of the absolute and relative fluctuating asymmetry indices had significantly lower values in individuals with tattoos/piercings than in the control group. This effect was strongly driven by males. Higher body symmetry of the men having tattoo or piercing indicates that this type of body decoration in the western society can be related to the honest signal of biological quality only for men. We did not find support for the “attractiveness increase hypothesis” for either sex.     

Yeast and other lower eukaryotic organisms for studies of Vps13 proteins in health and disease

Human Vps13 proteins are associated with several diseases, including the neurodegenerative disorder Chorea‐acanthocytosis (ChAc), yet the biology of these proteins is still poorly understood. Studies in Saccharomyces cerevisiae, Dictyostelium discoideum, Tetrahymena thermophila and Drosophila melanogaster point to the involvement of Vps13 in cytoskeleton organization, vesicular trafficking, autophagy, phagocytosis, endocytosis, proteostasis, sporulation and mitochondrial functioning. Recent findings show that yeast Vps13 binds to phosphatidylinositol lipids via 4 different regions and functions at membrane contact sites, enlarging the list of Vps13 functions. This review describes the great potential of simple eukaryotes to decipher disease mechanisms in higher organisms and highlights novel insights into the pathological role of Vps13 towards ChAc.      

Nuclear microsatellite markers reveal the low genetic structure of <Emphasis Type="Italic">Pinus mugo</Emphasis> Turra (dwarf mountain pine) populations in Europe

Twenty-one populations (555 individuals) covering the entire native range of Pinus mugo Turra (dwarf mountain pine) were investigated for genetic variation scored at 13 nuclear microsatellite markers (nSSRs). The main objective of the present study was to determine the genetic structure across the present distribution of the species and locate populations of different genetic compositions. Most of the genetic variation was observed within the populations (95%). The assignment of populations based on Bayesian clustering methods revealed that the Sudeten populations of P. mugo form a separate genetic cluster. These stands have likely been established through the founder effects of Alpine migrants. The distribution and level of SSR polymorphisms, along with no evidence of isolation by distance or phylogeographic structure, indicate that the present populations of P. mugo have diverged relatively recently and originate from a larger glacial distribution of the species. One peripheral stand from Italy had the lowest values of most calculated genetic variation indices. This stand could therefore be more susceptible to genetic drift and a negative impact of predicted environmental changes. We discuss our findings with respect to previously published results on the genetic and morphological variation of P. mugo and with consideration for the conservation genetics of the species.     

Mannose,but not glucose or sucrose,disturbs actin cytoskeleton in <Emphasis Type="Italic">Arabidopsis thaliana</Emphasis> leaves

A dynamic cytoskeleton able to recognize and respond to both abiotic and biotic stimuli is necessary for the proper functioning of a living cell. The cytoskeleton is involved in cell growth and division, maintenance of cell shape, cytoplasmic streaming, and organelle movements. Numerous studies have focused on the relationships between sugar metabolism, sugar signaling, and the cytoskeleton in yeast and animal cells. Data on such connections in plants are scarce. In the present study we investigated the effects of exogenously delivered sugars on the plant actin cytoskeleton. Detached Arabidopsis thaliana leaves were incubated with sugars for 2 days and the cytoskeleton was visualized using fluorescent-labeled phalloidin. Glucose and sucrose did not influence the pattern of the actin cytoskeleton. In contrast, mannose caused the disappearance of filamentous structures and generated actin foci. The symptoms started to be visible after 24 h of the exposure to mannose. The effect did not occur in Nicotiana tabacum mesophyll cells. This insensitivity was probably due to the presence of phosphomannose isomerase in tobacco cells. Mannose is commonly used as a selection marker for the transformation of plants lacking the enzymes responsible for the metabolism of mannose-6-phosphate. Exposure to this hexose has been linked with DNA fragmentation and a release of cytochrome c from mitochondria. Both responses are treated as features of programmed cell death. However, in our experiments no DNA laddering was observed in mannose-treated Arabidopsis leaves.