Mycoparasitism of Endophytic Fungi Isolated From Reed on Soilborne Phytopathogenic Fungi and Production of Cell Wall-Degrading Enzymes In Vitro

Antagonism of three endophytic fungi isolated from common reed (Phragmites australis) against eight soilborne pathogenic fungi was investigated on potato dextrose agar by light microscopy, scanning electron microscopy, and transmission electron microscopy. Inhibitory zones were not observed. The microscopical studies suggested that the endophytes inhibit growth of soilborne pathogens by means of coiling around hyphae and, after penetration, the degradation of hyphal cytoplasm. Since penetration of hyphae seems to play a major role in parasitism, we studied the production of cell wall degrading enzymes by the three endophytes. Choiromyces aboriginum produced higher activities of β-1,3-glucanases compared to Stachybotrys elegans and Cylindrocarpon sp. For C. aboriginum and S. elegans, colloidal chitin was the best substrate for the induction of β-1,3-glucanases and chitinases, respectively. This result suggests that mycoparasitism by endophytes on soilborne plant pathogens can be explained by their mycoparasitic activity.     

Improvement of the Fungal Biocontrol Agent Trichoderma atroviride To Enhance both Antagonism and Induction of Plant Systemic Disease Resistance

Biocontrol agents generally do not perform well enough under field conditions to compete with chemical fungicides. We determined whether transgenic strain SJ3-4 of Trichoderma atroviride, which expresses the Aspergillus niger glucose oxidase-encoding gene, goxA, under a homologous chitinase (nag1) promoter had increased capabilities as a fungal biocontrol agent. The transgenic strain differed only slightly from the wild-type in sporulation or the growth rate. goxA expression occurred immediately after contact with the plant pathogen, and the glucose oxidase formed was secreted. SJ3-4 had significantly less N-acetylglucosaminidase and endochitinase activities than its nontransformed parent. Glucose oxidase-containing culture filtrates exhibited threefold-greater inhibition of germination of spores of Botrytis cinerea. The transgenic strain also more quickly overgrew and lysed the plant pathogens Rhizoctonia solani and Pythium ultimum. In planta, SJ3-4 had no detectable improved effect against low inoculum levels of these pathogens. Beans planted in heavily infested soil and treated with conidia of the transgenic Trichoderma strain germinated, but beans treated with wild-type spores did not germinate. SJ3-4 also was more effective in inducing systemic resistance in plants. Beans with SJ3-4 root protection were highly resistant to leaf lesions caused by the foliar pathogen B. cinerea. This work demonstrates that heterologous genes driven by pathogen-inducible promoters can increase the biocontrol and systemic resistance-inducing properties of fungal biocontrol agents, such as Trichoderma spp., and that these microbes can be used as vectors to provide plants with useful molecules (e.g., glucose oxidase) that can increase their resistance to pathogens.     

Insect-damaged corn stalks decompose at rates similar to Bt-protected, non-damaged corn stalks

The relative decomposability of corn (Zea mays L.) residues from insect (Bt)-protected hybrids and conventional hybrids cultivated under insect pressure was investigated in two studies. Above-ground biomass, residue macromolecular composition, and stalk physical strength were also measured. In the first decomposition study, chopped residues (stalks and leaves) were used from a corn rootworm-protected (Cry3Bb1) hybrid and its non-Bt near isoline that were grown in replicated plots infested with corn rootworms (Diabrotica spp.). In the second study, residue (intact stalk sections) was used from three European corn borer (ECB, Ostrinia nubilalis Hübner)-resistant (Cry1Ab) hybrids representing different seed manufacturer/maturity date series, their non-Bt near isolines, two Cry3Bb1-protected isolines, and three additional conventional hybrids, all cultivated in replicated plots under conditions of elevated ECB pressure. In both studies, insect-resistant residues decomposed at rates similar to their non-protected near isolines. No evidence was found that insect-protected hybrids produced more above-ground biomass or had distinct residue composition. While some measures of mechanical stalk strength indicated that ECB-damaged stalks were not as stiff as protected stalks, these physical differences did not translate into differences in residue decomposition. We conclude that while individual hybrids may vary in their production of biomass, residue composition or residue decomposability, these characteristics do not systematically vary with the presence of the Bt gene conferring insect resistance, even under conditions of insect pressure.     

Immunohistochemical detection of secretoneurin, a novel neuropeptide endoproteolytically processed from secretogranin II, in normal human endocrine and neuronal tissues

Summary An antiserum raised against a synthetic peptide derived from the primary amino sequence of rat secretogranin II (chromogranin C) was used for immunological (quantitative radioimmunoassay analysis) and immunohistochemical studies of normal human endocrine and nervous tissues. This antibody recognized a novel and biologically active neuropeptide which was coined as secretoneurin. In endocrine tissues, secretoneurin was mainly co-localized with chromogranin A and B with some exceptions (e.g., parathyroid gland). Secretoneurin was demonstrated immunohistochemically in the adrenal medulla, thyroid C cells, TSH- and FSH/LH-produting cells of the anterior pituitary, A and B cells of pancreatic islets, in endocrine cells of the gastrointestinal tract and the bronchial mucosa, and the prostate. Immunoreactivity determined by radioimmunoassay analysis revealed high secretoneurin levels in the anterior and posterior pituitary and lower levels in pancreatic and thyroid tissue. A strong secretoneurin immunoreactivity was also found in ganglion cells of the submucdsal and myenteric plexus of the gastrointestinal tract, and in ganglionic cells of dorsal root ganglia, peripheral nerves, and ganglion cells of the adrenal medulla. Thus, secretoneurin may serve as a useful marker of gangliocytic/neuronal differentiation.     

Thermal unfolding of small proteins with SH3 domain folding pattern

The thermal unfolding of three SH3 domains of the Tec family of tyrosine kinases was studied by differential scanning calorimetry and CD spectroscopy. The unfolding transition of the three protein domains in the acidic pH region can be described as a reversible two-state process. For all three SH3 domains maximum stability was observed in the pH region 4.5 < pH < 7.0 where these domains unfold at temperatures of 353K (Btk), 342K (Itk), and 344K (Tec). At these temperatures an enthalpy change of 196 kJ/mol, 178 kJ/mol, and 169 kJ/mol was measured for Btk-, Itk-, and Tec-SH3 domains, respectively. The determined changes in heat capacity between the native and the denatured state are in an usual range expected for small proteins. Our analysis revealed that all SH3 domains studied are only weakly stabilized and have free energies of unfolding which do not exceed 12–16 kJ/mol but show quite high melting temperatures. Comparing unfolding free energies measured for eukaryotic SH3 domains with those of the topologically identical Sso7d protein from the hyperthermophile Sulfolobus solfataricus, the increased melting temperature of the thermostable protein is due to a broadening as well as a significant lifting of its stability curve. However, at their physiological temperatures, 310K for mesophilic SH3 domains and 350K for Sso7d, eukaryotic SH3 domains and Sso7d show very similar stabilities. Proteins 31:309–319, 1998. © 1998 Wiley-Liss, Inc.     

Stereoselective anti-Prelog reduction of ketones by whole cells of Comamonas testosteroni in a ‘substrate-coupled’ approach

Lyophilized cells of the open accessible bacterium Comamonas testosteroni DSM 1455 proved to be an excellent catalyst for the asymmetric reduction of different α-azido, α-bromo, and α-nitro ketones at elevated substrate concentrations (16 g/L) in a ‘substrate-coupled’ approach using 20% (v/v) of 2-propanol as hydrogen donor. Excellent anti-Prelog stereoselectivity was obtained, which is less common found in nature.     

Give What You Get: Capuchin Monkeys (Cebus apella) and 4-Year-Old Children Pay Forward Positive and Negative Outcomes to Conspecifics

The breadth of human generosity is unparalleled in the natural world, and much research has explored the mechanisms underlying and motivating human prosocial behavior. Recent work has focused on the spread of prosocial behavior within groups through paying-it-forward, a case of human prosociality in which a recipient of generosity pays a good deed forward to a third individual, rather than back to the original source of generosity. While research shows that human adults do indeed pay forward generosity, little is known about the origins of this behavior. Here, we show that both capuchin monkeys (Cebus apella) and 4-year-old children pay forward positive and negative outcomes in an identical testing paradigm. These results suggest that a cognitively simple mechanism present early in phylogeny and ontogeny leads to paying forward positive, as well as negative, outcomes.     

Rib lesions in skeletons from early neolithic sites in Central Germany: On the trail of tuberculosis at the onset of agriculture

As an infectious disease, tuberculosis (TB) is one of the major causes of death worldwide. Paleopathological and paleomicrobiological studies indicate a long standing association of the causative agent Mycobacterium tuberculosis and its human host. Since the occurrence and the epidemic spread of this pathogen seem to be closely linked to social and biological factors, it is of particular interest to understand better the role of TB during periods of social and nutritional change such as the Neolithic. In this study, 118 individuals from three sites in Saxony‐Anhalt (Germany) dating to the Linear Pottery Culture (5400–4800 BC) were examined macroscopically to identify TB related bone lesions. In two individuals, Pott's disease was detected. In addition, periosteal reactions of varying degrees and frequency were observed mainly along the neck of the ribs in 6.5% (2/31) of subadults and 35.1% (20/57) of adults, with one site standing out markedly. Rib lesions, however, are not specific indicators of TB as they can also be caused by other diseases; so additional investigations were undertaken using histology and micro‐CT scans to say more about the disease process. Supplementary molecular analyses indicate the presence of pathogens belonging to the Mycobacterium tuberculosis complex in individuals of all sites. Furthermore, we discuss the occurrence and spread of TB during the Neolithic with regard to nutritional aspects and possible risks of infection. The data presented provide important insights into the health status of Early Neolithic populations in Central Germany. Am J Phys Anthropol, 2012. © 2012 Wiley Periodicals, Inc.     

Determination of turnover of androstenedione to estrone via aromatase in estrogen receptor positive and negative human breast cancer cell lines [Poster 48]

In one estrogen receptor (ER) negative (MDA-MB-231) and two ER positive human breast cancer cell lines (T-47-D,SK-BR-3) we measured aromatase activity by [³H]water assay and estrone (E1) production by thin-layer chromatography. Compared with ether extraction and charcoal method, lyophilization proved to be the most sensitive technique to measure the quantity of [³H]water. The extremely low contamination of the water soluble phase by [1ß-³H]androstenedione (0.02%), as well as the lack of errors due to conjugated steroids, offers the possibility to measure changes of cellular aromatase activity even at very low levels. In contrast to SK-BR-3 and MDA-MB-231 cells, we found no aromatase activity in T-47-D cells. There was no coincidence between ER status and aromatase activity. Proliferation of tumor cells was parallel with a continuous increase of aromatase activity and E1 production during mitogenic growth phase reaching highest levels at the transition from log to plateau-phase.