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Junior research group VirusInteractNachwuchsgruppe VirusInteract

Junior research group VirusInteract

Research focus

  • Molecular plant virology
  • Interactome analysis of plant cell and virus
  • Plant viruses in biotechnology
  • Mechanisms of plant virus resistance

The aim of our research is to analyze and characterize the molecular mechanisms and interactions between plant cell & virus. Plant pathogens belonging to the families of Geminiviridae and Nanoviridae cause serious crop damage worldwide. These viruses have the capacity to re-program the cell to its favors by use of multifunctional virus proteins and interaction with host factors. We want to identify these functions and interaction partners with special focus on suppression of host pathogen response and intra- and intercellular viral transport to gain basic insights into virus infection and cellular functions.

Research projects

  • Analyzing plant stress granules in response to plant viruses

There is increasing evidence that, similar to mammalian cells, plant cells also utilize SGs for posttranscriptional gene control. Surprisingly, composition, function, and (dis)assembly mechanism of plant SGs is poorly investigated. Furthermore, there are only a few studies, which link biotic stress, e.g. virus infection with plant SGs, whereas there are numerous studies describing the role and the importance of SGs in counteracting viral infections in human or animal diseases. Therefore, we will stress the questions, if the Arabidopsis G3BP (a key enzyme for SG formation) is also essential in plant SGs formation (by KO and OEX approaches) and if we can identify other plant homologues of mammalian SGs (proteomic approach). Is G3BP function also affected by plant viruses to hamper proper SGs function and can we use this system to elucidate conserved mechanisms? Thus, the overall aim of this part of the study is to analyze and to characterize plant SGs and to elucidate their role in plant stress response, with special emphasis on viral infections.

This is a DFG funded project.

 

  • Development of a viral-based CRISPR/Cas-system for potato (DeviCCpo)

Plant genome editing is achieved by expression of sequence-specific nucleases (SSN). DNA-free RNA virus vector-mediated expression of SSNs is a promising approach for transgene integration-free targeted mutagenesis in plants. However, such a DNA-free RNA virus vector-system has not been fully established yet. The proposed project aims to develop an RNA virus-based CRISPR/Cas9-system to introduce gene-specific knock-outs in plants, as a proof-of-concept, but also for a novel application in potato. Second growth occurs when potato plants are grown under elevated temperatures and results in an up to 100% loss of marketable tubers. We will target a potato gene which will significantly improve tuber yield under heat stress. In addition, the RNA virus-based concept opens the possibility to transform meristematic tissue. Consequently, the RNA virus-based CRISPR/Cas9-system will be applied not only to potato leaf discs but also onto eyes of microtubers to simplify the technique and to enable gene targeting in a genotype independent manner.
Thus, the proposed project will not only develop a novel CRISPR/Cas9 delivery system, but also a novel application technique and, in addition, will assess a novel gene target in potato of commercial interest.

This is a BMBF sponsored project.

  

 

 

Molecular and cellular aspects of the life cycle of multipartite viruses: Nanoviruses

Emerging plant viruses are a threat worldwide. Studying their life cycles in details is a prerequisite to reveal alternative control strategies. We will target the family Nanoviridae for both practical and fundamental reasons: i) it represents a huge threat for Musaceae crop (genus Babuvirus) and for legumes (genus Nanovirus), and ii) it has adopted the enigmatic "multipartite" organization, with its genome composed of several nucleic acid segments each encapsidated individually. Nanoviruses being multipartite viruses with the highest number of genome segments described thus far, they are perfect models to investigate processes that might be specific to this viral genomic architecture most frequently adopted by plant viruses. In particular, how such viruses can efficiently infect a high proportion of cells/hosts with at least one copy of each of their numerous genome segments remains elusive. It is deemed impossible in the literature that actually questions the conceptual frame with which we try to comprehend the multipartite viral systems. Consistently, we recently showed that a nanovirus do not function in a way that fits the current concepts in virology. The virus spreads distinct genome segments in distinct individual cells of the host. These segments functionally complement across cells and thereby define a pluricellular way of life. This unprecedented discovery in virology now requires in depth investigation to decipher the mechanisms allowing such a surprising viral lifestyle. More specifically the Krenz group analyzes the viral proteins role during virus-host interactions, while the Blanc group studies the within-host viral population dynamics and the virus-vector interactions during plant-to-plant transmission. Through this project, we will join forces to study the full lifecycle. We propose to decipher the biochemical and biological properties of various nanoviral gene products interacting with host plants and aphid vectors. We aim to understand how distinct viral genome segments initially expressed in distinct plant cells actually function, how they can communicate and complement at a distance and at a supra-cellular scale. We will analyze the properties of the viral gene products with a focus on those with yet unknown function, and on properties that could be involved in trafficking among cells for complementation. Likewise, we will strive to understand how virus particles successfully travel through the body of their aphid vectors, ensuring that all segments are acquired, transported across aphid's cell barriers, and inoculated together.

This is a DFG funded project.