Pilzliche Verderbsflora von Möhren aus ökologischer und konventioneller Erzeugung

We investigated the fungal spoilage of carrots grown by different cultivation methods and stored at 5 °C at high humidity for up to 7 months. For this purpose, we used both microscopic analysis of pure cultures and DNA-based, culture-independent methods, namely, Single Strand Conformation Polymorphism (SSCP) and Terminal Restriction Length Polymorphism (T-RFLP). Moreover, fungi were identified on the basis of the sequences of 18S rDNA fragments from SSCP gels and from pure cultures. Additional analytical parameters included firmness and growth of two fungal strains on experi-mentally inoculated carrots. Both microscopic and DNA-based methods revealed that spoiled carrots cultivated at different sites carried different fungal species. The ob-served spectrum of species depended on the identification method. Using culture-independent methods, we detected fungi (e.g. species of basidiomycetes) not found on carrots up to now. No significant effect of the method of carrot cultivation (organic vs. conventional) on fungal spoilage patterns was observed. Likewise, no clear rela-tion between sites and methods of carrot cultivation and firmness or growth of experi-mentally inoculated fungi was found

Charakterisierung der Mikroflora und Beurteilung der Haltbarkeit verderblicher pflanzlicher Produkte aus ökologischer und konventioneller Erzeugung mit Hilfe neuer Methoden

Um festzustellen, wie sich unterschiedliche Anbauformen auf die spezifische Verderbsflora und die Lagerfähigkeit von Möhren und anderen verderblichen Erntegütern auswirken, wurde Erntegut aus definierter Erzeugung der Jahre 2004, 2005 und 2006 bis zu 7 Monaten bei 5°C und 95% rF gelagert. Vier von 42 eingelagerten Möhrenvarianten verdarben durch Pilze, davon zwei ökologische Feldversuchproben, die experimentell mit organischem Stickstoff „überdüngt“ worden waren. Weitere Hinweise auf einen Einfluss der Anbauform auf die Lagerfähigkeit gab es nicht. Die Fingerprint-Methoden SSCP und ARDRA weisen Unterschiede in der ribosomalen RNA nach und erfassten Unterschiede in der Zusammensetzung der Bakterienflora sowie deren Verschiebung während der Lagerung von Möhren. Deutliche Effekte der Anbauform gab es nicht. ARDRA und SSCP ergaben bei Reinkulturen von Pilzen unterschiedliche DNA Fragmentmuster. Die SSCP-Methode sowie die T-RFLP-Methode, einer Weiterentwicklung der ARDRA, erfasste Unterschiede in der Pilzflora bei Möhrenproben mit sichtbarem pilzlichen Verderb. Pilz-Reinkulturen von verdorbenen Möhren erwiesen sich sowohl morphologisch als auch nach Klonierung und Sequenzierung von rDNA im Wesentlichen als bekannte Erreger von Möhren-Lagerkrankheiten. Kultivierungsunabhängige Methoden (Sequenzierung von DNA Fragmenten aus SSCP-Gelen von Pilzgemeinschaften) ergaben auch Arten (z.B. von Basidiomyceten), die bisher noch nicht im Zusammenhang mit dem Verderb von Möhren beschrieben wurden. Diese Methodik erfasste auch Unterschiede in der Pilzflora verdorbener Zwiebeln, Pastinaken und Tomaten. Konventionelle mikrobiologische Methoden, Festigkeitsmessungen sowie die Wund Inokulation von Möhren mit Botrytis cinerea bzw. Fusarium sp. ergaben keine eindeutigen Hinweise auf einen Einfluss von Anbauform und Standort

Untersuchungen zur Erfassung von Unterschieden in der mikrobiellen Besiedlung und der Haltbarkeit von Möhren aus unterschiedlichen Anbauformen

Carrots cultivated by different methods were compared with respect to their response to post-harvest storage and inoculation with phytopathogenic fungi. No culture-related differences in firmness and in the behaviour of the carrots during lactic fermentation could be detected. Fresh (organic) carrots were found to be more rapidly colonized by Botrytis if they had been cultivated with additional organic nitrogen, and use of “bio-dynamic preparations” strengthened the colonization resistance of these carrots. The SSCP-method revealed different fingerprints of PCR-amplified bacterial DNA isolated from the surface of different batches of carrots. When carrots were stored for 6 month prior to inoculation, resistance against colonization by Fusarium sp. decreased, in particular if they had received additional nitrogen but no “biodynamic preparations”. The results indicate that a combination of inoculation studies, use of novel methods in characterizing the spoilage flora, and selected physical and organoleptic parameters has potential in detecting cultivation-dependent differences between batches of carrots with respect to their spoilage flora and shelf life

The salt-responsive transcriptome of chickpea roots and nodules via deepSuperSAGE

Background: The combination of high-throughput transcript profiling and next-generation sequencing technologies is a prerequisite for genome-wide comprehensive transcriptome analysis. Our recent innovation of deepSuperSAGE is based on an advanced SuperSAGE protocol and its combination with massively parallel pyrosequencing on Roche's 454 sequencing platform. As a demonstration of the power of this combination, we have chosen the salt stress transcriptomes of roots and nodules of the third most important legume crop chickpea (Cicer arietinum L.). While our report is more technology-oriented, it nevertheless addresses a major world-wide problem for crops generally: high salinity. Together with low temperatures and water stress, high salinity is responsible for crop losses of millions of tons of various legume (and other) crops. Continuously deteriorating environmental conditions will combine with salinity stress to further compromise crop yields. As a good example for such stress-exposed crop plants, we started to characterize salt stress responses of chickpeas on the transcriptome level. Results: We used deepSuperSAGE to detect early global transcriptome changes in salt-stressed chickpea. The salt stress responses of 86,919 transcripts representing 17,918 unique 26 bp deepSuperSAGE tags (UniTags) from roots of the salt-tolerant variety INRAT-93 two hours after treatment with 25 mM NaCl were characterized. Additionally, the expression of 57,281 transcripts representing 13,115 UniTags was monitored in nodules of the same plants. From a total of 144,200 analyzed 26 bp tags in roots and nodules together, 21,401 unique transcripts were identified. Of these, only 363 and 106 specific transcripts, respectively, were commonly up-or down-regulated (> 3.0-fold) under salt stress in both organs, witnessing a differential organ-specific response to stress. Profiting from recent pioneer works on massive cDNA sequencing in chickpea, more than 9,400 UniTags were able to be linked to UniProt entries. Additionally, gene ontology (GO) categories over-representation analysis enabled to filter out enriched biological processes among the differentially expressed UniTags. Subsequently, the gathered information was further cross-checked with stress-related pathways. From several filtered pathways, here we focus exemplarily on transcripts associated with the generation and scavenging of reactive oxygen species (ROS), as well as on transcripts involved in Na(+) homeostasis. Although both processes are already very well characterized in other plants, the information generated in the present work is of high value. Information on expression profiles and sequence similarity for several hundreds of transcripts of potential interest is now available. Conclusions: This report demonstrates, that the combination of the high-throughput transcriptome profiling technology SuperSAGE with one of the next-generation sequencing platforms allows deep insights into the first molecular reactions of a plant exposed to salinity. Cross validation with recent reports enriched the information about the salt stress dynamics of more than 9,000 chickpea ESTs, and enlarged their pool of alternative transcripts isoforms

Systemic virus distribution and host responses in brain and intestine of chickens infected with low pathogenic or high pathogenic avian influenza virus

<p>Abstract</p> <p>Background</p> <p>Avian influenza virus (AIV) is classified into two pathotypes, low pathogenic (LP) and high pathogenic (HP), based on virulence in chickens.</p> <p>Differences in pathogenicity between HPAIV and LPAIV might eventually be related to specific characteristics of strains, tissue tropism and host responses.</p> <p>Methods</p> <p>To study differences in disease development between HPAIV and LPAIV, we examined the first appearance and eventual load of viral RNA in multiple organs as well as host responses in brain and intestine of chickens infected with two closely related H7N1 HPAIV or LPAIV strains.</p> <p>Results</p> <p>Both H7N1 HPAIV and LPAIV spread systemically in chickens after a combined intranasal/intratracheal inoculation. In brain, large differences in viral RNA load and host gene expression were found between H7N1 HPAIV and LPAIV infected chickens. Chicken embryo brain cell culture studies revealed that both HPAIV and LPAIV could infect cultivated embryonic brain cells, but in accordance with the absence of the necessary proteases, replication of LPAIV was limited. Furthermore, TUNEL assay indicated apoptosis in brain of HPAIV infected chickens only. In intestine, where endoproteases that cleave HA of LPAIV are available, we found minimal differences in the amount of viral RNA and a large overlap in the transcriptional responses between HPAIV and LPAIV infected chickens. Interestingly, brain and ileum differed clearly in the cellular pathways that were regulated upon an AI infection.</p> <p>Conclusions</p> <p>Although both H7N1 HPAIV and LPAIV RNA was detected in a broad range of tissues beyond the respiratory and gastrointestinal tract, our observations indicate that differences in pathogenicity and mortality between HPAIV and LPAIV could originate from differences in virus replication and the resulting host responses in vital organs like the brain.</p

Mutagenesis and Functional Studies with Succinate Dehydrogenase Inhibitors in the Wheat Pathogen Mycosphaerella graminicola

A range of novel carboxamide fungicides, inhibitors of the succinate dehydrogenase enzyme (SDH, EC 1.3.5.1) is currently being introduced to the crop protection market. The aim of this study was to explore the impact of structurally distinct carboxamides on target site resistance development and to assess possible impact on fitness

When Correction Turns Positive:Processing Corrective Prosody in Dutch

Current research on spoken language does not provide a consistent picture as to whether prosody, the melody and rhythm of speech, conveys a specific meaning. Perception studies show that English listeners assign meaning to prosodic patterns, and, for instance, associate some accents with contrast, whereas Dutch listeners behave more controversially. In two ERP studies we tested how Dutch listeners process words carrying two types of accents, which either provided new information (new information accents) or corrected information (corrective accents), both in single sentences (experiment 1) and after corrective and new information questions (experiment 2). In both experiments corrective accents elicited a sustained positivity as compared to new information accents, which started earlier in context than in single sentences. The positivity was not modulated by the nature of the preceding question, suggesting that the underlying neural mechanism likely reflects the construction of an interpretation to the accented word, either by identifying an alternative in context or by inferring it when no context is present. Our experimental results provide strong evidence for inferential processes related to prosodic contours in Dutch

Molekulare Muster der bakteriellen Besiedelung von Möhren aus ökologischer und konventioneller Erzeugung

Um festzustellen, wie sich unterschiedliche Anbauformen auf die bakterielle Besiedlung von Möhren auswirken, wurde Erntegut aus definierter Erzeugung bis zu sieben Monate gelagert (5°C, 95% relative Feuchte) und die bakterielle Flora auf der Oberfläche mit Hilfe DNA-basierter Fingerprint-Methoden charakterisiert. Während der Lagerung verdarben vier von 34 Möhrenvarianten sichtbar durch Pilze, davon zwei Proben von Möhren aus ökologischem Anbau, die experimentell im Rahmen eines Feldversuchs mit organischem Stickstoff „überdüngt“ worden waren. Die Fingerprint-Methoden SSCP (Single Strand Conformation Polymorphism) und ARDRA (Amplified Ribosomal DNA Restriction Analysis) weisen Unterschiede in der ribosomalen RNA nach und erfassten Unterschiede in der Zusammensetzung der Bakterienflora sowie deren Verschiebung während der Lagerung von Möhren. Deutliche Effekte der Anbauform gab es nicht. Die T-RFLP(Terminal Restriction Fragment Length Polymorphism)-Methode, eine Weiterentwicklung der ARDRA, erfasste Unterschiede in der Bakterienbesiedlung bei Möhrenproben mit sichtbarem Verderb