Nonribosomal peptides, key biocontrol components for Pseudomonas fluorescens In5, isolated from a Greenlandic suppressive soil.

UnlabelledPotatoes are cultivated in southwest Greenland without the use of pesticides and with limited crop rotation. Despite the fact that plant-pathogenic fungi are present, no severe-disease outbreaks have yet been observed. In this report, we document that a potato soil at Inneruulalik in southern Greenland is suppressive against Rhizoctonia solani Ag3 and uncover the suppressive antifungal mechanism of a highly potent biocontrol bacterium, Pseudomonas fluorescens In5, isolated from the suppressive potato soil. A combination of molecular genetics, genomics, and matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) imaging mass spectrometry (IMS) revealed an antifungal genomic island in P. fluorescens In5 encoding two nonribosomal peptides, nunamycin and nunapeptin, which are key components for the biocontrol activity by strain In5 in vitro and in soil microcosm experiments. Furthermore, complex microbial behaviors were highlighted. Whereas nunamycin was demonstrated to inhibit the mycelial growth of R. solani Ag3, but not that of Pythium aphanidermatum, nunapeptin instead inhibited P. aphanidermatum but not R. solani Ag3. Moreover, the synthesis of nunamycin by P. fluorescens In5 was inhibited in the presence of P. aphanidermatum. Further characterization of the two peptides revealed nunamycin to be a monochlorinated 9-amino-acid cyclic lipopeptide with similarity to members of the syringomycin group, whereas nunapeptin was a 22-amino-acid cyclic lipopeptide with similarity to corpeptin and syringopeptin.ImportanceCrop rotation and systematic pest management are used to only a limited extent in Greenlandic potato farming. Nonetheless, although plant-pathogenic fungi are present in the soil, the farmers do not experience major plant disease outbreaks. Here, we show that a Greenlandic potato soil is suppressive against Rhizoctonia solani, and we unravel the key biocontrol components for Pseudomonas fluorescens In5, one of the potent biocontrol bacteria isolated from this Greenlandic suppressive soil. Using a combination of molecular genetics, genomics, and microbial imaging mass spectrometry, we show that two cyclic lipopeptides, nunamycin and nunapeptin, are important for the biocontrol activity of P. fluorescens In5 both in vitro and in microcosm assays. Furthermore, we demonstrate that the synthesis of nunamycin is repressed by the oomycete Pythium aphanidermatum. Overall, our report provides important insight into interkingdom interference between bacteria and fungi/oomycetes

Radial Bargmann representation for the Fock space of type B

Let $\nu_{\alpha,q}$ be the probability and orthogonality measure for the $q$-Meixner-Pollaczek orthogonal polynomials, which has appeared in \cite{BEH15} as the distribution of the $(\alpha,q)$-Gaussian process (the Gaussian process of type B) over the $(\alpha,q)$-Fock space (the Fock space of type B). The main purpose of this paper is to find the radial Bargmann representation of $\nu_{\alpha,q}$. Our main results cover not only the representation of $q$-Gaussian distribution by \cite{LM95}, but also of $q^2$-Gaussian and symmetric free Meixner distributions on $\mathbb R$. In addition, non-trivial commutation relations satisfied by $(\alpha,q)$-operators are presented.Comment: 13 pages, minor changes have been mad

Baryogenesis by B - L generation due to superheavy particle decay

We have shown that the $B-L$ generation due to the decay of the thermally produced superheavy fields can explain the Baryon assymmetry in the universe if the superheavy fields are heavier than $10^{13-14}$ GeV. Note that although the superheavy fields have non-vanishing charges under the standard model gauge interactions, the thermally prduced baryon asymmetry is sizable. The $B-L$ violating effective operators induced by integrating the superheavy fields have dimension 7, while the operator in the famous leptogenesis has dimension 5. Therefore, the constraints from the nucleon stability can be easily satisfied.Comment: 12 pages, 4 figures, 3 table

NSTX tangential divertor camera

Strong magnetic field shear around the divertor x-point is numerically predicted to lead to strong spatial asymmetries in turbulence driven particle fluxes. To visualize the turbulence and associated impurity line emission near the lower x-point region, a new tangential observation port has been recently installed on NSTX. A reentrant sapphire window with a moveable in-vessel mirror images the divertor region from the center stack out to R 80 cm and views the x-point for most plasma configurations. A coherent fiber optic bundle transmits the image through a remotely selected filter to a fast camera, for example a 40500 frames/sec Photron CCD camera. A gas puffer located in the lower inboard divertor will localize the turbulence in the region near the x-point. Edge fluid and turbulent codes UEDGE and BOUT will be used to interpret impurity and deuterium emission fluctuation measurements in the divertor

50-plus years of fungal viruses

AbstractMycoviruses are widespread in all major taxa of fungi. They are transmitted intracellularly during cell division, sporogenesis, and/or cell-to-cell fusion (hyphal anastomosis), and thus their life cycles generally lack an extracellular phase. Their natural host ranges are limited to individuals within the same or closely related vegetative compatibility groups, although recent advances have established expanded experimental host ranges for some mycoviruses. Most known mycoviruses have dsRNA genomes packaged in isometric particles, but an increasing number of positive- or negative-strand ssRNA and ssDNA viruses have been isolated and characterized. Although many mycoviruses do not have marked effects on their hosts, those that reduce the virulence of their phytopathogenic fungal hosts are of considerable interest for development of novel biocontrol strategies. Mycoviruses that infect endophytic fungi and those that encode killer toxins are also of special interest. Structural analyses of mycoviruses have promoted better understanding of virus assembly, function, and evolution

A Direct Method for Measuring Heat Conductivity in Intracluster Medium

The inverse Compton scattering of the cosmic microwave background (CMB) radiation with electrons in the intracluster medium which has a temperature gradient, was examined by the third-order perturbation theory of the Compton scattering. A new type of the spectrum distortion of the CMB was found and named as gradient T Sunyaev-Zel'dovich effect (gradT SZE). The spectrum has an universal shape. The spectrum crosses over zero at 326GHz. The sign of the spectrum depends on the relative direction of the line-of-sight to the direction of the temperature gradient. This unique spectrum shape can be used to detect the gradT SZE signal by broad-band or multi-frequency observations of the SZE. The amplitude of the spectrum distortion does not depend on the electron density and is proportional to the heat conductivity. Therefore, the gradT SZE provides an unique opportunity to measure thermally nonequilibrium electron momentum distribution function when the ICM has a temperature gradient and the heat conductivity in the ICM. However, the expected amplitude of the signal is very small. The modifications to the thermal SZE spectrum due to variety of known effects, such as relativistic correction etc., can become problematic when using multi-frequency separation techniques to detect the gradT SZE signal.Comment: 18pages, 3figures, accepted for publication in Ap

Capsid Structure of dsRNA Fungal Viruses

Most fungal, double-stranded (ds) RNA viruses lack an extracellular life cycle stage and are transmitted by cytoplasmic interchange. dsRNA mycovirus capsids are based on a 120-subunit T = 1 capsid, with a dimer as the asymmetric unit. These capsids, which remain structurally undisturbed throughout the viral cycle, nevertheless, are dynamic particles involved in the organization of the viral genome and the viral polymerase necessary for RNA synthesis. The atomic structure of the T = 1 capsids of four mycoviruses was resolved: the L-A virus of Saccharomyces cerevisiae (ScV-L-A), Penicillium chrysogenum virus (PcV), Penicillium stoloniferum virus F (PsV-F), and Rosellinia necatrix quadrivirus 1 (RnQV1). These capsids show structural variations of the same framework, with 60 asymmetric or symmetric homodimers for ScV-L-A and PsV-F, respectively, monomers with a duplicated similar domain for PcV, and heterodimers of two different proteins for RnQV1. Mycovirus capsid proteins (CP) share a conserved α-helical domain, although the latter may carry different peptides inserted at preferential hotspots. Insertions in the CP outer surface are likely associated with enzymatic activities. Within the capsid, fungal dsRNA viruses show a low degree of genome compaction compared to reoviruses, and contain one to two copies of the RNA-polymerase complex per virion