Kruse C.,University of Heidelberg |
Haas F.H.,University of Heidelberg |
Jost R.,Murdoch University |
Reiser B.,RLP AgroScience GmbH |
And 5 more authors.
Journal of Plant Physiology | Year: 2012
The antifungal activities of many sulfur-containing defense compounds suggest a connection between pathogen infection, primary sulfur metabolism and sulfate nutritional status of plants. This relationship was investigated using Arabidopsis thaliana plants that were cultivated under different sulfur regimes and challenged by Alternaria brassicicola. Plants grown with 500 μM sulfate were significantly less infected compared to plants grown on 50 μM sulfate. Upon infection, the formation of the sulfur-containing defense compound camalexin and the gene expression of the sulfur-rich defense peptide defensin were clearly enhanced in plants grown with an optimal compared to a sufficient sulfate supply in the growth medium. Elevated levels of sulfite and O-acetylserine and cysteine biosynthetic enzymes after infection indicated a stimulation of sulfur metabolism under the higher sulfate supply. The results suggest that, in addition to pathogen-triggered activation of sulfur metabolism and sulfur-containing defense compound formation, the sulfate nutritional status is sensed to contribute to plant defense. © 2012 Elsevier GmbH.
Dalakouras A.,RLP AgroScience GmbH |
Dadami E.,RLP AgroScience GmbH |
Wassenegger M.,RLP AgroScience GmbH |
Wassenegger M.,University of Heidelberg
Viruses | Year: 2015
Viroids are non-encapsidated, non-coding, circular, single-stranded RNAs (ssRNAs). They are classified into the families Pospiviroidae and Avsunviroidae, whose members replicate in the nucleus and chloroplast of plant cells, respectively. Viroids have a wide host range, including crop and ornamental plants, and can cause devastating diseases with significant economic losses. Thus, several viroids are world-wide, classified as quarantine pathogens and, hence, there is an urgent need for the development of robust antiviroid strategies. RNA silencing-based technologies seem to be a promising tool in this direction. Here, we review the recent advances concerning the complex interaction of viroids with the host’s RNA silencing machinery, evaluate past and present antiviroid approaches, and finally suggest alternative strategies that could potentially be employed in the future in order to achieve transgenic and non-transgenic viroid-free plants. © 2015 by the authors; licensee MDPI, Basel, Switzerland.
Rosenhauer M.,Bingen University of Applied Sciences |
Felsenstein F.G.,EpiGene GmbH |
Piepho H.-P.,University of Hohenheim |
Hofer M.,RLP AgroScience GmbH |
Petersen J.,Bingen University of Applied Sciences
Weed Research | Year: 2015
Non-target-site resistance (NTSR) comprises a set of mechanisms conferring resistance to multiple modes of action. Investigation of the number of loci involved in NTSR will aid in the understanding of these resistance mechanisms. Therefore, six different multiple herbicide-resistant Alopecurus myosuroides plants with different herbicide history were crossed in two generations with a susceptible wild type. Seeds from the backcrossing generation were studied for their segregation rate for resistance to five herbicides with four different modes of action (HRAC groups C2, A, B and K3). Taking into account that NTSR is a set of quantitative traits, the numbers of loci controlling NTSR were estimated using a normal mixture model fitted by the NLMIXED procedure of SAS. Each herbicide was controlled by a different number of loci comparing the six plants. In most of the cases, chlorotoluron resistance was controlled by one locus, whereas resistance to fenoxaprop-P-ethyl needed one or two loci. Resistance to pinoxaden was in all plants conferred by two loci. Cross-resistance of fenoxaprop-P-ethyl and pinoxaden was found in all backcrossings, indicating that at least one of the two loci is responsible for both resistances. Resistance to mesosulfuron + iodosulfuron was conferred by a minimum of two loci. Results indicated that a minimum of five different loci can be involved in a multiple NTSR plant. Furthermore, the plant-specific accumulation of NTSR loci was demonstrated. Such behaviour should be taken into account when evaluating the development and further spread of herbicide resistance. © 2015 European Weed Research Society.
PubMed | University of Heidelberg and RLP AgroScience GmbH
Type: Journal Article | Journal: Viruses | Year: 2015
Viroids are non-encapsidated, non-coding, circular, single-stranded RNAs (ssRNAs). They are classified into the families Pospiviroidae and Avsunviroidae, whose members replicate in the nucleus and chloroplast of plant cells, respectively. Viroids have a wide host range, including crop and ornamental plants, and can cause devastating diseases with significant economic losses. Thus, several viroids are world-wide, classified as quarantine pathogens and, hence, there is an urgent need for the development of robust antiviroid strategies. RNA silencing-based technologies seem to be a promising tool in this direction. Here, we review the recent advances concerning the complex interaction of viroids with the hosts RNA silencing machinery, evaluate past and present antiviroid approaches, and finally suggest alternative strategies that could potentially be employed in the future in order to achieve transgenic and non-transgenic viroid-free plants.
Duker A.,RLP AgroScience GmbH |
Kubiak R.,RLP AgroScience GmbH
Journal of Plant Diseases and Protection | Year: 2011
Stem injection of prohexadione carboxylic acid (pca) was tested to prevent blossom infection by the fire blight pathogen Erwinia amylovora on apple trees, as an alternative to applying streptomycin (Plantomycin ®). Under glasshouse conditions, the reduction in blossom infection by E. amylovora on two-year-old container-grown plants by injecting 40 mg pca was similar as applying Plantomycin ®. Under field conditions, the injection of just 10 mg pca in four-year-old field-grown trees resulted in reduced primary fire blight infection identical to that of Plantomycin ®. In both experiments, however, shoot stunting in apple trees treated with pca was observed. In addition, yield losses occurred in the field experiment, probably caused by reduced longitudinal growth. Concentrations of residues of pca in the fruits of apple trees treated with 30 and 40 mg pca were 0.0032 ppm and 0.0017 ppm, respectively, and well below the EU's reference value (0.05 ppm). Consequently, the use of stem-injected pca under field conditions is not constrained by residues in the end product. Problems caused by stunting of shoots and associated yield losses after injection with pca and the technical realisation of stem injection in orchards were discussed. © Eugen Ulmer KG, Stuttgart.
Duker A.,RLP AgroScience GmbH |
Kubiak R.,RLP AgroScience GmbH
Vitis - Journal of Grapevine Research | Year: 2011
The aim of this study was to find suitable substances to control powdery mildew by means of stem injection. The triazoles myclobutanil, penconazol and tebuconazol were used as test substances. In the first experiment, single xylem injections of these triazoles were carried out to test their effect against powdery mildew. The injections were carried out on field-grown grapevines using the ChemJet̄tree injector. Applications invariably yielded efficiency factors of over 60%. A practiceoriented effect on leaves and grapes was most notably gained using tebuconazol. In the second experiment, the repeated xylem injection of myclobutanil, penconazol and tebuconazol was carried out on field-grown grapevines with a prototypal stationary injection system to evaluate the longer-term effects. Grapevines sprayed with formulated myclobutanil (Systhane 20 EW̄penconazol (Topas̄and tebuconazol (Folicur 250 EW̄ enable the methods to be compared. Applications using the prototypal stationary injection system only yielded moderate efficiency factors. A practice-oriented effect was gained using the sprayed application. Future options for stem injection, such as combating wood-destroying fungi and phytoplasmosis, were discussed.
Luders A.,University of Kaiserslautern |
Muller C.,University of Kaiserslautern |
Boonrod K.,RLP Agroscience GmbH |
Krczal G.,RLP Agroscience GmbH |
Ziegler C.,University of Kaiserslautern
Colloids and Surfaces B: Biointerfaces | Year: 2012
Spherical plant viruses like the tomato bushy stunt virus (TBSV) allow for multiple applications in nanotechnology due to their shape. In this article, different types of the virus were created by extending coat protein (CP) at carboxylic termini with 2 different charged amino acids by point mutation. The obtained CPs carried 6 aspartic acid (negative charge) and 4 histamine (positive charge) residues. The ability of TBSV to form self assembled monolayers with large ordered areas on native and chemically modified mica will be presented. The structural differences between layers formed by the wild type and by the genetically modified types will be discussed in detail. © 2011 Elsevier B.V.
RLP AgroScience GmbH | Date: 2011-11-23
The present invention relates to a method for isolating small RNA-molecules (sRNAs) from a sample using Helper-component-protein (HC-Pro) from potyviruses. The present invention furthermore relates to an improved method for isolating sRNAs from a sample using HC-Pro together with a cupin protein or the cupin 2-superfamily domain thereof. The methods of the present invention can be used in the treatment, diagnosis and monitoring of diseases, for screening compounds modifying the number, amount, and/or concentration of sRNAs. Finally, the invention also relates to a kit for isolating sRNAs from a sample.
RLP AgroScience GmbH | Date: 2010-06-23
The present invention relates to materials and methods for the production of a transgene-free plant with altered methylation patterns. Particular embodiments of the invention provide methods, nucleic acids, vectors, plant cells, plants and kits, suitable to produce a plant, which is devoid of any transgenic materials, and therefore is transgene-free, but which shows an altered DNA methylation pattern. The present invention furthermore relates to methods, nucleic acids, vectors, plant cells, plants and kits for the production of a transgene-free plant wherein the altered methylation pattern results in the differential expression of a gene. Finally, the present invention also encompasses a method for modifying the methylation pattern in a target DNA sequence of a plant cell.