Geisenheim University

Geisenheim, Germany

Geisenheim University

Geisenheim, Germany
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Graeber K.,University of London | Graeber K.,Albert Ludwigs University of Freiburg | Linkies A.,Albert Ludwigs University of Freiburg | Linkies A.,Geisenheim University | And 12 more authors.
Proceedings of the National Academy of Sciences of the United States of America | Year: 2014

Seed germination is an important life-cycle transition because it determines subsequent plant survival and reproductive success. To detect optimal spatiotemporal conditions for germination, seeds act as sophisticated environmental sensors integrating information such as ambient temperature. Here we show that the DELAY OF GERMINATION 1 (DOG1) gene, known for providing dormancy adaptation to distinct environments, determines the optimal temperature for seed germination. By reciprocal gene-swapping experiments between Brassicaceae species we show that the DOG1-mediated dormancy mechanism is conserved. Biomechanical analyses showthat thismechanism regulates the material properties of the endosperm, a seed tissue layer acting as germination barrier to control coat dormancy. We found that DOG1 inhibits the expression of gibberellin (GA)-regulated genes encoding cell-wall remodeling proteins in a temperature-dependent manner. Furthermore we demonstrate that DOG1 causes temperature-dependent alterations in the seed GA metabolism. These alterations in hormone metabolism are brought about by the temperature-dependent differential expression of genes encoding key enzymes of the GA biosynthetic pathway. These effects of DOG1 lead to a temperature-dependent control of endosperm weakening and determine the optimal temperature for germination. The conserved DOG1-mediated coat-dormancymechanismprovides a highly adaptable temperature-sensing mechanism to control the timing of germination.

Hanf J.H.,Geisenheim University | Schweickert E.,Geisenheim University
Journal of Wine Research | Year: 2014

Wine cooperatives have a long tradition and still account for roughly a third of the German wine market. Based on cooperative values and seven cooperative principles, the legally manifested business goal of cooperatives is to patronize their members' business activities. As the members are grape growers, member-orientation leads to a business policy of production-orientation which stands in strong contrast to the customer orientation which is associated with saturated competitive markets. The aim of this article is to analyse this area of conflict. Based on the results of this analysis, we intend to shed some light on the relation between the wines produced by cooperatives and their origin as a means of marketing. © 2014 Taylor & Francis.

Reineke A.,Geisenheim University | Thiery D.,CNRS Agroecology Lab
Journal of Pest Science | Year: 2016

We review direct and indirect effects of climate change on both the grapevine plant as a host for phytophagous insects, as well as on grape insect pests, their natural enemies and corresponding future grape plant protection strategies. Phenology, voltinism and distribution ranges are well known traits of many arthropods influenced by temperature as the key abiotic factor and thus by current and future climate change scenarios. Case studies of grapevine pests based on data from three decades point to clear changes in phenology of grape berry moths, shifts in distribution ranges of leafhoppers as vectors of grapevine diseases and range expansion of grapevine mealybugs. These case studies also illustrate the need to include data on putatively changed tri-trophic interactions in vineyards when predicting impacts of climate change on grapevine pest insects. Hence, future pest management strategies should be based on a sound set of field data obtained for both pests and antagonists under changed abiotic conditions, which can also build the basis for refining and extending currently existing models for forecasting population levels of respective insect pests. © 2016 Springer-Verlag Berlin Heidelberg

Szolnoki G.,Geisenheim University
Journal of Cleaner Production | Year: 2013

This cross-national study investigates different aspects of sustainability from the wine producers' point of view. A qualitative study conducted with fifty-five wine producers in the USA, France, Spain, Italy, Germany, Hungary and Greece was undertaken to analyse the producers' definition, evaluation and practice of sustainability in the wine industry. Results show that the interviewed producers mainly associated the term sustainability solely with the environmental dimension; whereas some wineries applied a more complete approach of sustainability including not only the environmental, but also the economic as well as the social dimensions. Regarding the production management systems, there is some ambiguity since many of the interviewees confuse the terms organic, biodynamic and sustainable. The majority of the wineries participating in this study complain about the lack of information among relevant organizations, producers and consumers concerning sustainability. The barriers to this flow of information might be the great challenge the sustainable wine industry will face in future. All these findings indicate the necessity of closer cooperation of national organizations on an international level in order to provide the information needed by the wine producers and consumers. © 2013 Elsevier Ltd. All rights reserved.

Kecskemeti E.,Geisenheim University | Berkelmann-Lohnertz B.,Geisenheim University | Reineke A.,Geisenheim University
PLoS ONE | Year: 2016

Using barcoded pyrosequencing fungal and bacterial communities associated with grape berry clusters (Vitis vinifera L.) obtained from conventional, organic and biodynamic vineyard plots were investigated in two subsequent years at different stages during berry ripening. The four most abundant operational taxonomic units (OTUs) based on fungal ITS data were Botrytis cinerea, Cladosporium spp., Aureobasidium pullulans and Alternaria alternata which represented 57% and 47% of the total reads in 2010 and 2011, respectively. Members of the genera Sphingomonas, Gluconobacter, Pseudomonas, Erwinia, and Massilia constituted 67% of the total number of bacterial 16S DNA reads in 2010 samples and 78% in 2011 samples. Viticultural management system had no significant effect on abundance of fungi or bacteria in both years and at all three sampling dates. Exceptions were A. alternata and Pseudomonas spp. which were more abundant in the carposphere of conventional compared to biodynamic berries, as well as Sphingomonas spp. which was significantly less abundant on conventional compared to organic berries at an early ripening stage in 2011. In general, there were no significant differences in fungal and bacterial diversity indices or richness evident between management systems. No distinct fungal or bacterial communities were associated with the different maturation stages or management systems, respectively. An exception was the last stage of berry maturation in 2011, where the Simpson diversity index was significantly higher for fungal communities on biodynamic compared to conventional grapes. Our study highlights the existence of complex and dynamic microbial communities in the grape cluster carposphere including both phytopathogenic and potentially antagonistic microorganisms that can have a significant impact on grape production. Such knowledge is particularly relevant for development, selection and application of effective control measures against economically important pathogens present in the grape carposphere. © 2016 Kecskeméti et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Otto D.,Johannes Gutenberg University Mainz | Petersen R.,Johannes Gutenberg University Mainz | Brauksiepe B.,Geisenheim University | Braun P.,Geisenheim University | Schmidt E.R.,Johannes Gutenberg University Mainz
Molecular Breeding | Year: 2014

The columnar growth habit of apple trees (Malus × domestica Borkh.) is a unique plant architecture phenotype that arose as a bud sport mutation of a McIntosh tree in the 1960s. The mutation ("Co gene") led to trees (McIntosh Wijcik) with thick, upright main stems and short internodes that generate short fruit spurs instead of long lateral branches. Although Co has been localized to chromosome 10, in a region approximately between 18.5 and 19 Mb, its molecular nature is unknown. In a classical positional cloning approach in combination with the analysis of NGS data, we cloned and analyzed the Co region. Our results show that the insertion of a Ty3/Gypsy retrotransposon into a non-coding region at position 18.8 Mb is the only detectable genomic difference between McIntosh and McIntosh Wijcik and is found in all columnar cultivars. The genetic effect of the insertion is unclear; however, Illumina® RNA-seq data of McIntosh and McIntosh Wijcik suggest that the columnar growth habit is associated with differential expression of the retrotransposon transcript, causing changes in the expression levels of many protein coding genes. The mechanism by which the Gypsy retrotransposon is involved in generating the columnar habit is not yet clear; our findings form the basis for tackling this question. © 2013 Springer Science+Business Media Dordrecht.

Bonisch F.,TU Munich | Frotscher J.,Geisenheim University | Stanitzek S.,University of Bonn | Ruhl E.,Geisenheim University | And 3 more authors.
Plant Physiology | Year: 2014

Terpenoids represent one of the major classes of natural products and serve different biological functions. In grape (Vitis vinifera), a large fraction of these compounds is present as nonvolatile terpene glycosides. We have extracted putative glycosyltransferase (GT) sequences from the grape genome database that show similarity to Arabidopsis (Arabidopsis thaliana) GTs whose encoded proteins glucosylate a diversity of terpenes. Spatial and temporal expression levels of the potential VvGT genes were determined in five different grapevine varieties. Heterologous expression and biochemical assays of candidate genes led to the identification of a UDP-glucose: monoterpenol b-D-glucosyltransferase (VvGT7). The VvGT7 gene was expressed in various tissues in accordance with monoterpenyl glucoside accumulation in grape cultivars. Twelve allelic VvGT7 genes were isolated from five cultivars, and their encoded proteins were biochemically analyzed. They varied in substrate preference and catalytic activity. Three amino acids, which corresponded to none of the determinants previously identified for other plant GTs, were found to be important for enzymatic catalysis. Site-specific mutagenesis along with the analysis of allelic proteins also revealed amino acids that impact catalytic activity and substrate tolerance. These results demonstrate that VvGT7 may contribute to the production of geranyl and neryl glucoside during grape ripening. © 2014 American Society of Plant Biologists. All Rights Reserved.

Bonisch F.,TU Munich | Frotscher J.,Geisenheim University | Stanitzek S.,University of Bonn | Ruhl E.,Geisenheim University | And 3 more authors.
Plant Physiology | Year: 2014

Monoterpenols serve various biological functions and accumulate in grape (Vitis vinifera), where a major fraction occurs as nonvolatile glycosides. We have screened the grape genome for sequences with similarity to terpene URIDINE DIPHOSPHATE GLYCOSYLTRANSFERASES (UGTs) from Arabidopsis (Arabidopsis thaliana). A ripening-related expression pattern was shown for three candidates by spatial and temporal expression analyses in five grape cultivars. Transcript accumulation correlated with the production of monoterpenyl β-D-glucosides in grape exocarp during ripening and was low in vegetative tissue. Targeted functional screening of the recombinant UGTs for their biological substrates was performed by activity-based metabolite profiling (ABMP) employing a physiologic library of aglycones built from glycosides isolated from grape. This approach led to the identification of two UDP-glucose:monoterpenol β-D-glucosyltransferases. Whereas VvGT14a glucosylated geraniol, R,S-citronellol, and nerol with similar efficiency, the three allelic forms VvGT15a, VvGT15b, and VvGT15c preferred geraniol over nerol. Kinetic resolution of R,S-citronellol and R,S-linalool was shown for VvGT15a and VvGT14a, respectively. ABMP revealed geraniol as the major biological substrate but also disclosed that these UGTs may add to the production of further glycoconjugates in planta. ABMP of aglycone libraries provides a versatile tool to uncover novel biologically relevant substrates of small-molecule glycosyltransferases that often show broad sugar acceptor promiscuity. © 2014 American Society of Plant Biologists. All Rights Reserved.

Guardiola M.,CSIC - Center for Advanced Studies of Blanes | Frotscher J.,Geisenheim University | Uriz M.-J.,CSIC - Center for Advanced Studies of Blanes
Marine Biology | Year: 2016

Sponges are considered poor invaders, and no genetic studies on introduced sponges have been performed up to now. Paraleucilla magna is the first calcareous sponge introduced to the Mediterranean and Northeastern Atlantic. The study aimed at investigating the genetic makeup and connectivity of the introduced populations of P. magna and at exploring signs of local phenotypic adaptation, to gain insight on the species invasive potential. Ten populations along the species introduction range (Brazil, Açores, Madeira, and continental Europe) were genetically characterized by using nine microsatellite markers. Most populations were genetically structured as suggested by significant Dst and Fst values, significant differences among populations (AMOVA) and the presence of private alleles. The analyzed populations belonged to three genetically homogeneous groups (K) according to the Bayesian algorithm (structure software) and the UPGMA dendrogram. Genetic diversity within populations was higher than expected. Recurrent introductions of non-randomly selected individuals from the native sources may have contributed to the heterozygote deficit found in all populations by forming pedigree structures with mating among relatives. Moreover, the species biological cycle was monitored in a population established on native Mediterranean assemblages (41°40′27″N, 2°47′25″E) and compared with the species cycle in other habitats. Contrasting life spans, growth habits, and reproduction cycles, depending on the habitat conditions, were recorded. To summarize, high genetic diversity, phenotypic local adaptation, and high reproduction rates altogether allow predicting the fast proliferation of P. magna in newly colonized regions and point to its strong invasive potential. © 2016, The Author(s).

Chen T.-W.,Leibniz University of Hanover | Kahlen K.,Geisenheim University | Stutzel H.,Leibniz University of Hanover
Plant, Cell and Environment | Year: 2015

There are conflicting opinions on the relative importance of photosynthetic limitations under salinity. Quantitative limitation analysis of photosynthesis provides insight into the contributions of different photosynthetic limitations, but it has only been applied under saturating light conditions. Using experimental data and modelling approaches, we examined the influence of light intensity on photosynthetic limitations and quantified the osmotic and ionic effects of salinity on stomatal (LS), mesophyll (LM), biochemical (LB) and light (LL) limitations in cucumber (Cucumis sativusL.) under different light intensities. Non-linear dependencies of LS, LM and LL to light intensity were found. Osmotic effects on LS and LM increased with the salt concentration in the nutrient solution (Ss) and the magnitude of LM depended on light intensity. LS increased with the Na+ concentration in the leaf water (Sl) and its magnitude depended on Ss. Biochemical capacity declined linearly with Sl but, surprisingly, the relationship between LB and Sl was influenced by Ss. © 2014 John Wiley & Sons Ltd.

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