We attempted to improve the adventitious regeneration protocol in styrian oil pumpkin for subsequent use in somaclonal variation studies. The endoreduplication status of tissues might play an important role, so endopolyploidy was analyzed by flow cytometry in different organs and major differences were revealed. Endoreduplication was minimal in leaves but in other organs—particularly in the hypocotyl and epicotyl—levels up to 64C were found. The basal part of cotyledons has been reported to be the most responsive for adventitious regeneration and, using image cytometry, we identified it as the least endoreduplicated section, with a cycle value of 1.29 compared to 1.78 and 1.80 in the central and distal parts. Basal cotyledonary explants were subjected to various media combinations. Fusaric acid was added to media as a possible selective agent for somaclonal variation inducing increased tolerance to Fusarium but was surprisingly found to stimulate regeneration at a low concentration (5 mg L−1) and to induce genome doubling at medium concentrations (10 and 20 mg L−1).
COBISS.SI-ID: 7983737
Newly emerging or re-emerging diseases are a constant and significant threat to agricultural production, so prompt and accurate identification of the causative agents is required for rapid and appropriate disease management. Classical methods of pathogen detection can be successfully supplemented by next-generation sequencing (NGS), whereby sequence analysis can help in the discovery of new or emerging diseases. In 2007, hop growers in Slovenia reported the appearance of severely stunted hop plants, a phenomenon that spread rapidly within hop gardens and among farms. Classical diagnostic methods were unable to detect a new pathogen; therefore, single step high-throughput parallel sequencing of total RNA and small RNAs from plants with and without symptoms was employed to identify a novel pathogen. The sequences were assembled de novo and also mapped to reference genomes, resulting in identification of a novel sequence of Citrus bark cracking viroid (CBCVd) in the stunted hop plants. Furthermore, the presence of this novel pathogen on hop was confirmed by RT-PCR analysis of 59 plants with symptoms from 15 hop gardens, representing the main outbreak locations identified by systematic disease monitoring, and small RNA Illumina sequencing of the bulked RNA sample. The high infectivity of the newly identified CBCVd was also confirmed by biolistic inoculation of two hop cultivars, which developed aggressive symptoms in controlled conditions. This study shows the feasibility of deep sequencing for the identification of causative agents of new diseases in hop and other plants.
COBISS.SI-ID: 8056185
In this study, mild and lethal isolates from three countries were grown in simulated xylem medium and secretome analysis by 2D-DIGE showed low qualitative and high quantitative variability among the isolates. Functional classification of 194 identified proteins representing 100 unique protein accessions revealed an arsenal of cell wall-degrading enzymes and potential effectors. The set of proteins that were more abundant in at least two lethal isolates included enzymes acetylcholinesterases, lipases, polygalacturonases, pectate lyase, rhamnogalacturonan acetylesterases, acetylxylan esterase, endoglucanase, xylanases, mannosidases, and a protein similar to alginate lyase and also potential effectors necrosis- and ethylene-inducing protein, small basic 14 kDa hypothetical protein and 79 kDa hypothetical proteins.Other proteins associated with virulence showed different expression profiles between mild and lethal isolates. The results suggest that the increased virulence of lethal isolates has little background shared by all three lethal isolates and that upregulation of isolate specific sets of proteins may be most important.
COBISS.SI-ID: 8088441
In this work interaction between hop and V.albo-atrum was studied on the transcriptome level. The results gave us first insight Time course experiments was set up to follow fungal colonization patterns and interactions of resistant and susceptible hop cultivars infected with V. albo-atrum. Quantification of fungal DNA showed marked differences in spatial and temporal fungal colonization patterns in the two cultivars. Two differential display methods obtained 217 transcripts with altered expression, of which 84 showed similarity to plant proteins and 7 fungal proteins. Gene ontology categorised them into cellular and metabolic processes, response to stimuli, biological regulation, biogenesis and localization. The expression patterns of 17 transcripts with possible implication in plant immunity were examined by real-time PCR (RT-qPCR). Our results showed strong expression of genes encoding PR proteins in susceptible plants and strong up-regulation of genes implicated in ubiquitination and vesicle trafficking in the incompatible interaction and their down-regulation in susceptible plants, suggesting the involvement of these processes in the hop resistance reaction. In the resistant cultivar, the RT-qPCR expression patterns of most genes showed their peak at 20 dpi and declined towards 30 dpi, comparable to the gene expression pattern of in planta detected fungal protein and coinciding with the highest fungal biomass in plants at 15 dpi. These expression patterns suggest that the defence response in the resistant cultivar is strong enough at 20 dpi to restrict further fungus colonization. This study has been extended by the application of RNA-seq approach.
COBISS.SI-ID: 7992953
In the frame of Cost action FA1003 (04/11/2010 03/11/2014) “EastWest Collaboration for Grapevine Diversity Exploration and Mobilization of Adaptive Traits for Breeding” we improved knowledge of grapevine genetic diversity, which is essential for its long term conservation and sustainable use. The Action strengthened scientific excellence through the creation of a new interdisciplinary network. The Action bridged the actual gap that exists between the west and east European scientific communities working on grapevine genetics and breeding. It lead to completing the characterization and improved availability of research knowledge on grapevine genetic resources from the countries in eastern Europe and at the same time enpower the scientists from east European countries to participate, develop and share the results of innovative approaches of modern genetics. SCI publications published as the result of the project: MAUL, Erika, ŠTAJNER, Nataša, FAILLA, Osvaldo, et al. Identification and characterization of grapevine genetic resources maintained in Eastern European Collections. Vitis, ISSN 0042-7500, 2015, vol. 54, spec. iss., str. 5-12. http://pub.jki.bund.de/index.php/VITIS/article/view/4948. [COBISS.SI-ID 8232057], ŠTAJNER, Nataša, TOMIĆ, Lidija, PROGAR, Vasja, POKORN, Tine, LACOMBE, Thierry, LAUCOU, Valérie, BOURSIQUOT, Jean-Michel, JAVORNIK, Branka, BACILIERI, Roberto. Genetic clustering and parentage analysis of Western Balkan grapevines (Vitis vinifera L.). Vitis, ISSN 0042-7500, 2015, vol. 54, spec. iss., str. 67-72. http://pub.jki.bund.de/index.php/VITIS/article/view/5113. [COBISS.SI-ID 8231801], RUSJAN, Denis, BUBOLA, Marijan, JANJANIN, D., UŽILA, Zoran, RADEKA, Sanja, POLJUHA, Danijela, PELENGIĆ, Radojko, JAVORNIK, Branka, ŠTAJNER, Nataša. Ampelographic characterisation of grapevine accessions denominated 'Refošk', 'Refosco', 'Teran' and 'Terrano' (Vitis vinifera L.) from Slovenia, Croatia and Italy. Vitis, ISSN 0042-7500, 2015, vol. 54, spec. iss., str. 77-80. http://pub.jki.bund.de/index.php/VITIS/article/download/4982/4772. [COBISS.SI-ID 8223353] RUSJAN, Denis, PELENGIĆ, Radojko, PIPAN, Barbara, OR, E., JAVORNIK, Branka, ŠTAJNER, Nataša. Israeli germplasm: phenotyping and genotyping of native grapevines (Vitis vinifera L.). Vitis, ISSN 0042-7500, 2015, vol. 54, spec. iss., str. 87-89. http://pub.jki.bund.de/index.php/VITIS/article/download/4984/4774. [COBISS.SI-ID 8223609]
COBISS.SI-ID: 8232057