1. Dynamics of responses in compatible potato - potato virus Y interaction are modulated by salicylic acidŠpela Baebler, Katja Stare, Maja Kovač, Andrej Blejec, Nina Prezelj, Tjaša Stare, Polona Kogovšek, Maruša Pompe Novak, S. Rosahl, Maja Ravnikar, Kristina Gruden, 2011, izvirni znanstveni članek Povzetek: To investigate the dynamics of the potato – Potato virus Y (PVY) compatible interaction in relation to salicylic acid - controlled pathways we performed experiments using non-transgenic potato cv. Désirée, transgenic NahG-Désirée, cv. Igor and PVYNTN, the most aggressive strain of PVY. The importance of salicylic acid in viral multiplication and symptom development was confirmed by pronounced symptom development in NahG-Désirée, depleted in salicylic acid, and reversion of the effect after spraying with 2,6-dichloroisonicotinic acid (a salicylic acid - analogue). We have employed quantitative PCR for monitoring virus multiplication, as well as plant responses through expression of selected marker genes of photosynthetic activity, carbohydrate metabolism and the defence response. Viral multiplication was the slowest in inoculated potato of cv. Désirée, the only asymptomatic genotype in the study. The intensity of defence-related gene expression was much stronger in both sensitive genotypes (NahG-Désirée and cv. Igor) at the site of inoculation than in asymptomatic plants (cv. Désirée). Photosynthesis and carbohydrate metabolism gene expression differed between the symptomatic and asymptomatic phenotypes. The differential gene expression pattern of the two sensitive genotypes indicates that the outcome of the interaction does not rely simply on one regulatory component, but similar phenotypical features can result from distinct responses at the molecular level.
Ključne besede: plant viruses, plant diseases
Objavljeno v DiRROS: 04.03.2025; Ogledov: 297; Prenosov: 152
 Celotno besedilo (632,53 KB)
Gradivo ima več datotek! Več... |
2. Chloroplast vesiculation and induced chloroplast vesiculation and senescence-associated gene 12 expression during tomato flower pedicel abscissionMagda Tušek-Žnidarič, Maja Zagorščak, Živa Ramšak, Katja Stare, Marko Chersicola, Maruša Pompe Novak, Aleš Kladnik, Marina Dermastia, 2025, izvirni znanstveni članek Povzetek: Abscission is a tightly regulated process in which plants shed unnecessary, infected, damaged, or aging organs, as well as ripe fruits, through predetermined abscission zones in response to developmental, hormonal, and environmental signals. Despite its importance, the underlying mechanisms remain incompletely understood. This study highlights the deleterious effects of abscission on chloroplast ultrastructure in the cells of the tomato flower pedicel abscission zone, revealing spatiotemporal differential gene expression and key transcriptional networks involved in chloroplast vesiculation during abscission. Significant changes in chloroplast structure and vesicle formation were observed 8 and 14 h after abscission induction, coinciding with the differential expression of vesiculation-related genes, particularly with upregulation of Senescence-Associated Gene 12 (SAG12) and Chloroplast Vesiculation (CV). This suggests a possible vesicle transport of chloroplast degrading material for recycling by autophagy-independent senescence-associated vacuoles (SAVs) and CV-containing vesicles (CCVs). Ethylene signaling appears to be involved in the regulation of these processes, as treatment with a competitive inhibitor of ethylene action, 1-methylcyclopropene, delayed vesiculation, reduced the expression of SAG12, and increased expression of Curvature Thylakoid 1A (CURT1A). In addition, chloroplast vesiculation during abscission was associated with differential expression of photosynthesis-related genes, particularly those involved in light reactions, underscoring the possible functional impact of the observed structural changes. This work provides new insights into the molecular and ultrastructural mechanisms underlying abscission and offers potential new targets for agricultural or biotechnological applications.
Ključne besede: abscission, chloroplast vesiculation, CURT1A, CV-containing vesicle, senescence-associated vacuole, ethylene, gene expression, tomato flower pedicel
Objavljeno v DiRROS: 10.01.2025; Ogledov: 476; Prenosov: 239
Celotno besedilo (10,69 MB)
Gradivo ima več datotek! Več... |
3. The StPti5 ethylene response factor acts as a susceptibility factorby negatively regulating the potato immune responseto pathogensAnna Coll Rius, Tjaša Lukan, Katja Stare, Maja Zagorščak, Tjaša Mahkovec Povalej, Špela Baebler, Salomé Prat, Núria Sánchez Coll, Marc Valls, Marko Petek, Kristina Gruden, 2024, izvirni znanstveni članek Povzetek: Ethylene response factors (ERFs) have been associated with biotic stress in Arabidopsis, while their function in non-model plants is still poorly understood. Here we investigated the role of potato ERF StPti5 in plant immunity.
We show that StPti5 acts as a susceptibility factor. It negatively regulates potato immunity against potato virus Y and Ralstonia solanacearum, pathogens with completely different modes of action, and thereby has a different role than its orthologue in tomato. Remarkably, StPti5 is destabilised in healthy plants via the autophagy pathway and accumulates exclusively in the nucleus upon infection. We demonstrate that StEIN3 and StEIL1 directly bind the StPti5 promoter and activate its expression, while synergistic activity of the ethylene and salicylic acid pathways is required for regulated StPti expression.
To gain further insight into the mode of StPti5 action in attenuating potato defence responses, we investigated transcriptional changes in salicylic acid deficient potato lines with silenced StPti5 expression. We show that StPti5 regulates the expression of other ERFs and downregulates the ubiquitin-proteasome pathway as well as several proteases involved in directed proteolysis.
This study adds a novel element to the complex puzzle of immune regulation, by deciphering a two-level regulation of ERF transcription factor activity in response to pathogens.
Ključne besede: ethylene response factor, immune signalling, potato virus Y, Pti5, Ralstonia solanacearum, Solanum tuberosum, susceptibility factor
Objavljeno v DiRROS: 29.08.2024; Ogledov: 664; Prenosov: 871
Celotno besedilo (2,55 MB)
Gradivo ima več datotek! Več... |
4. Salicylic acid is an indispensable component of the Ny-1 resistance-gene-mediated response against Potato virus Y infection in potatoŠpela Baebler, Kamil Witek, Marko Petek, Katja Stare, Magda Tušek-Žnidarič, Maruša Pompe Novak, Jenny Renaut, K. Szajko, D. Strzelczyk-Żyta, W. Marczewski, Karolina Morgiewicz, Kristina Gruden, Jacek Hennig, 2014, izvirni znanstveni članek Povzetek: The purpose of the study was to investigate the role of salicylic acid (SA) signalling in Ny-1-mediated hypersensitive resistance (HR) of potato (Solanum tuberosum L.) to Potato virus Y (PVY). The responses of the Ny-1 allele in the Rywal potato cultivar and transgenic NahG-Rywal potato plants that do not accumulate SA were characterized at the cytological, biochemical, transcriptome, and proteome levels. Analysis of noninoculated and inoculated leaves revealed that HR lesions started to develop from 3 d post inoculation and completely restricted the virus spread. At the cytological level, features of programmed cell death in combination with reactive oxygen species burst were observed. In response to PVY infection, SA was synthesized de novo. The lack of SA accumulation in the NahG plants led to the disease phenotype due to unrestricted viral spreading. Grafting experiments show that SA has a critical role in the inhibition of PVY spreading in parenchymal tissue, but not in vascular veins. The whole transcriptome analysis confirmed the central role of SA in orchestrating Ny-1-mediated responses and showed that the absence of SA leads to significant changes at the transcriptome level, including a delay in activation of expression of genes known to participate in defence responses. Moreover, perturbations in the expression of hormonal signalling genes were detected, shown as a switch from SA to jasmonic acid/ethylene signalling. Viral multiplication in the NahG plants was accompanied by downregulation of photosynthesis genes and activation of multiple energy-producing pathways.
Ključne besede: plant-pathogen interactions, Potato virus Y, salicylic acid, whole transcriptome analysis
Objavljeno v DiRROS: 01.08.2024; Ogledov: 643; Prenosov: 435
Celotno besedilo (4,98 MB)
Gradivo ima več datotek! Več... |
5. Bimodal dynamics of primary metabolism-related responses in tolerant potato-Potato virus Y interactionNeža Turnšek, Živa Ramšak, Katja Stare, Tjaša Stare, Dominik Vodnik, Andrej Blejec, Kristina Gruden, Wolfram Weckwerth, Stefanie Wienkoop, 2015, izvirni znanstveni članek Povzetek: Background
Potato virus Y (PVY) is a major pathogen that causes substantial economic losses in worldwide potato production. Different potato cultivars differ in resistance to PVY, from severe susceptibility, through tolerance, to complete resistance. The aim of this study was to better define the mechanisms underlying tolerant responses of potato to infection by the particularly aggressive PVYNTN strain. We focused on the dynamics of the primary metabolism-related processes during PVYNTN infection.
Results
A comprehensive analysis of the dynamic changes in primary metabolism was performed, which included whole transcriptome analysis, nontargeted proteomics, and photosynthetic activity measurements in potato cv. Désirée and its transgenic counterpart depleted for accumulation of salicylic acid (NahG-Désirée). Faster multiplication of virus occurred in the NahG-Désirée, with these plants developing strong disease symptoms. We show that while the dynamics of responses at the transcriptional level are extensive and bimodal, this is only partially translated to the protein level, and to the final functional outcome. Photosynthesis-related genes are transiently induced before viral multiplication is detected and it is down-regulated later on. This is reflected as a deficiency of the photosynthetic apparatus at the onset of viral multiplication only. Interestingly, specific and constant up-regulation of some RuBisCO transcripts was detected in Désirée plants, which might be important, as these proteins have been shown to interact with viral proteins.
In SA-deficient and more sensitive NahG-Désirée plants, consistent down-regulation of photosynthesis-related genes was detected. A constant reduction in the photochemical efficiency from the onset of viral multiplication was identified; in nontransgenic plants this decrease was only transient. The transient reduction in net photosynthetic rate occurred in both genotypes with the same timing, and coincided with changes in stomatal conductivity.
Conclusions
Down-regulation of photosynthesis-related gene expression and decreased photosynthetic activity is in line with other studies that have reported the effects of biotic stress on photosynthesis. Here, we additionally detected induction of light-reaction components in the early stages of PVYNTN infection of tolerant interaction. As some of these components have already been shown to interact with viral proteins, their overproduction might contribute to the absence of symptoms in cv. Désirée.
Ključne besede: plant-pathogen interactions, Potato virus Y, potyviridae, salicylic acid, whole transcriptome analysis, shot-gun proteomics, photosynthetic parameters
Objavljeno v DiRROS: 29.07.2024; Ogledov: 705; Prenosov: 485
 Povezava na celotno besedilo
Gradivo ima več datotek! Več... |
6. Comparison between proteome and transcriptome response in potato (Solanum tuberosum L.) leaves following potato virus Y (PVY) infectionTjaša Stare, Katja Stare, Wolfram Weckwerth, Stefanie Wienkoop, Kristina Gruden, 2017, izvirni znanstveni članek Povzetek: Plant diseases caused by viral infection are affecting all major crops. Being an obligate intracellular organisms, chemical control of these pathogens is so far not applied in the field except to control the insect vectors of the viruses. Understanding of molecular responses of plant immunity is therefore economically important, guiding the enforcement of crop resistance. To disentangle complex regulatory mechanisms of the plant immune responses, understanding system as a whole is a must. However, integrating data from different molecular analysis (transcriptomics, proteomics, metabolomics, smallRNA regulation etc.) is not straightforward. We evaluated the response of potato (Solanum tuberosum L.) following the infection with potato virus Y (PVY). The response has been analyzed on two molecular levels, with microarray transcriptome analysis and mass spectroscopy-based proteomics. Within this report, we performed detailed analysis of the results on both levels and compared two different approaches for analysis of proteomic data (spectral count versus MaxQuant). To link the data on different molecular levels, each protein was mapped to the corresponding potato transcript according to StNIB paralogue grouping. Only 33% of the proteins mapped to microarray probes in a one-to-one relation and additionally many showed discordance in detected levels of proteins with corresponding transcripts. We discussed functional importance of true biological differences between both levels and showed that the reason for the discordance between transcript and protein abundance lies partly in complexity and structure of biological regulation of proteome and transcriptome and partly in technical issues contributing to it.
Ključne besede: proteomics, transcriptomics, potato, potato virus Y
Objavljeno v DiRROS: 24.07.2024; Ogledov: 694; Prenosov: 416
Celotno besedilo (1,41 MB)
Gradivo ima več datotek! Več... |
7. quantGenius : implementation of a decision support system for qPCR-based gene quantificationŠpela Baebler, Miha Svalina, Marko Petek, Katja Stare, Ana Rotter, Maruša Pompe Novak, Kristina Gruden, 2017, izvirni znanstveni članek Povzetek: Background
Quantitative molecular biology remains a challenge for researchers due to inconsistent approaches for control of errors in the final results. Due to several factors that can influence the final result, quantitative analysis and interpretation of qPCR data are still not trivial. Together with the development of high-throughput qPCR platforms, there is a need for a tool allowing for robust, reliable and fast nucleic acid quantification.
Results
We have developed “quantGenius” (http://quantgenius.nib.si), an open-access web application for a reliable qPCR-based quantification of nucleic acids. The quantGenius workflow interactively guides the user through data import, quality control (QC) and calculation steps. The input is machine- and chemistry–independent. Quantification is performed using the standard curve approach, with normalization to one or several reference genes. The special feature of the application is the implementation of user-guided QC-based decision support system, based on qPCR standards, that takes into account pipetting errors, assay amplification efficiencies, limits of detection and quantification of the assays as well as the control of PCR inhibition in individual samples. The intermediate calculations and final results are exportable in a data matrix suitable for further statistical analysis or visualization. We additionally compare the most important features of quantGenius with similar advanced software tools and illustrate the importance of proper QC system in the analysis of qPCR data in two use cases.
Conclusions
To our knowledge, quantGenius is the only qPCR data analysis tool that integrates QC-based decision support and will help scientists to obtain reliable results which are the basis for biologically meaningful data interpretation.
Ključne besede: quantitative molecular biology, quantitative PCR, nucleic acid quantification, web application, decision support system
Objavljeno v DiRROS: 24.07.2024; Ogledov: 653; Prenosov: 371
Celotno besedilo (1,49 MB)
Gradivo ima več datotek! Več... |
8. Structural basis for the multitasking nature of the potato virus Y coat proteinAndreja Kežar, Luka Kavčič, Martin Pólak, Jiři Nováček, Ion Gutiérrez-Aguirre, Magda Tušek-Žnidarič, Anna Coll Rius, Katja Stare, Kristina Gruden, Maja Ravnikar, David Pahovnik, Ema Žagar, Franci Merzel, Gregor Anderluh, Marjetka Podobnik, 2019, izvirni znanstveni članek Povzetek: Potato virus Y (PVY) is among the most economically important plant pathogens. Using cryoelectron microscopy, we determined the near-atomic structure of PVY’s flexuous virions, revealing a previously unknown lumenal interplay between extended carboxyl-terminal regions of the coat protein units and viral RNA. RNA–coat protein interactions are crucial for the helical configuration and stability of the virion, as revealed by the unique near-atomic structure of RNA-free virus-like particles. The structures offer the first evidence for plasticity of the coat protein’s amino- and carboxyl-terminal regions. Together with mutational analysis and in planta experiments, we show their crucial role in PVY infectivity and explain the ability of the coat protein to perform multiple biological tasks. Moreover, the high modularity of PVY virus-like particles suggests their potential as a new molecular scaffold for nanobiotechnological applications.
Ključne besede: plant pathogens, potato virus Y, viral RNA
Objavljeno v DiRROS: 23.07.2024; Ogledov: 672; Prenosov: 404
Celotno besedilo (4,43 MB)
Gradivo ima več datotek! Več... |
9. Precision transcriptomics of viral foci reveals the spatial regulation of immune-signaling genes and identifies RBOHD as an important player in the incompatible interaction between potato virus Y and potatoTjaša Lukan, Maruša Pompe Novak, Špela Baebler, Magda Tušek-Žnidarič, Aleš Kladnik, Maja Križnik, Andrej Blejec, Maja Zagorščak, Katja Stare, Barbara Dušak, Anna Coll Rius, Stephan Pollmann, Karolina Morgiewicz, Jacek Hennig, Kristina Gruden, 2020, izvirni znanstveni članek Povzetek: Whereas the activation of resistance (R) proteins has been intensively studied, the downstream signaling mechanisms leading to the restriction of the pathogen remain mostly unknown. We studied the immunity network response conditioned by the potato Ny-1 gene against potato virus Y. We analyzed the processes in the cell death zone and surrounding tissue on the biochemical and gene expression levels in order to reveal the spatiotemporal regulation of the immune response. We show that the transcriptional response in the cell death zone and surrounding tissue is dependent on salicylic acid (SA). For some genes the spatiotemporal regulation is completely lost in the SA-deficient line, whereas other genes show a different response, indicating multiple connections between hormonal signaling modules. The induction of NADPH oxidase RBOHD expression occurs specifically on the lesion border during the resistance response. In plants with silenced RBOHD, the functionality of the resistance response is perturbed and the spread of the virus is not arrested at the site of infection. RBOHD is required for the spatial accumulation of SA, and conversely RBOHD is under the transcriptional regulation of SA. Using spatially resolved RNA-seq, we also identified spatial regulation of an UDP-glucosyltransferase, another component in feedback activation of SA biosynthesis, thus deciphering a novel aspect of resistance signaling.
Ključne besede: immune signaling network, NADPH oxidase RBOHD, reactive oxygen species, salicylic acid, Sola-num tuberosum (potato), spatiotemporal response analysis, virus resistance, Potyvirus
Objavljeno v DiRROS: 22.07.2024; Ogledov: 646; Prenosov: 391
Celotno besedilo (2,87 MB)
Gradivo ima več datotek! Več... |
10. CCR5-mediated signaling is involved in invasion of glioblastoma cells in its microenvironmentMetka Novak, Miha Koprivnikar Krajnc, Barbara Hrastar, Barbara Breznik, Bernarda Majc, Mateja Mlinar, Ana Rotter, Andrej Porčnik, Jernej Mlakar, Katja Stare, Richard G. Pestell, Tamara Lah Turnšek, 2020, izvirni znanstveni članek Povzetek: Abstract
The chemokine CCL5/RANTES is a versatile inflammatory mediator, which interacts with the receptor CCR5, promoting cancer cell interactions within the tumor microenvironment. Glioblastoma is a highly invasive tumor, in which CCL5 expression correlates with shorter patient survival. Using immunohistochemistry, we identified CCL5 and CCR5 in a series of glioblastoma samples and cells, including glioblastoma stem cells. CCL5 and CCR5 gene expression were significantly higher in a cohort of 38 glioblastoma samples, compared to low-grade glioma and non-cancerous tissues. The in vitro invasion of patients-derived primary glioblastoma cells and glioblastoma stem cells was dependent on CCL5-induced CCR5 signaling and is strongly inhibited by the small molecule CCR5 antagonist maraviroc. Invasion of these cells, which was enhanced when co-cultured with mesenchymal stem cells (MSCs), was inhibited by maraviroc, suggesting that MSCs release CCR5 ligands. In support of this model, we detected CCL5 and CCR5 in MSC monocultures and glioblastoma-associated MSC in tissue sections. We also found CCR5 expressing macrophages were in close proximity to glioblastoma cells. In conclusion, autocrine and paracrine cross-talk in glioblastoma and, in particular, glioblastoma stem cells with its stromal microenvironment, involves CCR5 and CCL5, contributing to glioblastoma invasion, suggesting the CCL5/CCR5 axis as a potential therapeutic target that can be targeted with repositioned drug maraviroc.
Ključne besede: CCL5, CCR5, chemokines, glioblastoma, invasion, maraviroc, mesenchymal stem cells
Objavljeno v DiRROS: 22.07.2024; Ogledov: 707; Prenosov: 256
Povezava na datoteko |
