Analysis of Vir protein translocation from Agrobacterium tumefaciens using Saccharomyces cerevisiae as a model: evidence for transport of a novel effector protein VirE3

Plant sciencesMicrobial Biotechnolog

VirB/D4-dependent protein translocation from Agrobacterium into plant cells

Microbial BiotechnologyPlant science

LandSense: Coupling citizen science and earth observation data to promote environmental monitoring

The Horizon 2020 project, LandSense, is a modern citizen observatory for Land Use & Land Cover (LULC) monitoring, that connects citizens with Earth Observation (EO) data to transform current approaches to environmental decision making. Citizen Observatories are community-driven mechanisms to complement existing environmental monitoring systems and can be fostered through EO-based mobile and web applications, allowing citizens to not only play a key role in LULC monitoring, but also to be directly involved in the co-creation of such solutions. Within LandSense, citizens can participate in ongoing demonstration pilots using their own devices (e.g. mobile phones and tablets), through interactive reporting, gaming applications and mapathons. Campaigns in Vienna, Toulouse, Amsterdam, Serbia, Spain and Indonesia address topics such as urban greenspaces, agricultural management and biodiversity/habitat threat monitoring. For example, in the case of Toulouse and Indonesia, hotspots of change in LULC are identified through Sentinel 2 time series analysis. These hotspots are then validated by citizens and interested stakeholders either directly on-site via customized mobile applications, providing geotagged photos, or remotely via the online LandSense Engagement platform. The presentation will not only showcase the tools and results from these campaigns, but also highlight how citizen-driven observations can contribute to sustainable development. Such initiatives present clear opportunities to integrate citizen-driven observations with established authoritative data sources to further extend GEOSS and Copernicus capacities, and support comprehensive environmental monitoring systems. In addition, these applications have considerable potential in lowering expenditure costs on in-situ data collection and current calibration/validation approaches within the processing chain of environmental monitoring activities both within and beyond Europe

Origin and Evolution of GALA-LRR, a New Member of the CC-LRR Subfamily: From Plants to Bacteria?

The phytopathogenic bacterium Ralstonia solanacearum encodes type III effectors, called GALA proteins, which contain F-box and LRR domains. The GALA LRRs do not perfectly fit any of the previously described LRR subfamilies. By applying protein sequence analysis and structural prediction, we clarify this ambiguous case of LRR classification and assign GALA-LRRs to CC-LRR subfamily. We demonstrate that side-by-side packing of LRRs in the 3D structures may control the limits of repeat variability within the LRR subfamilies during evolution. The LRR packing can be used as a criterion, complementing the repeat sequences, to classify newly identified LRR domains. Our phylogenetic analysis of F-box domains proposes the lateral gene transfer of bacterial GALA proteins from host plants. We also present an evolutionary scenario which can explain the transformation of the original plant LRRs into slightly different bacterial LRRs. The examination of the selective evolutionary pressure acting on GALA proteins suggests that the convex side of their horse-shoe shaped LRR domains is more prone to positive selection than the concave side, and we therefore hypothesize that the convex surface might be the site of protein binding relevant to the adaptor function of the F-box GALA proteins. This conclusion provides a strong background for further functional studies aimed at determining the role of these type III effectors in the virulence of R. solanacearum

Crowdsourcing public perceptions of urban green space quality: A case study of Rembrandt park in Amsterdam

City-dwellers are realizing the benefits of green spaces and are flocking to urban parks. City planners face the challenge of ensuring that urban green spaces are functional for all citizens. To make informed choices they need the right information and that is where the Mijn Park app can help. Research shows that when considering the social functions of urban green spaces, quality is just as important as quantity. It is easy enough to map how much green spaces there are, but how do we measure their quality? How do city planners ensure that the city?s green areas are attractive, accessible and inclusive ? for everyone? The Vrije Universiteit Amsterdam in collaboration with the International Institute for Applied Systems Analysis developed Mijn Park, a mobile application that will help city planners do just that. As part of the LandSense Citizen Observatory, the ?Mijn Park? (My Park) app asks respondents to go to several locations in a park and give subjective responses to those locations. They are then further questioned about how they use the whole park and how much they would like to see certain changes made in the park. This information provides information that can help to inform decisions about any renovations or improvements to the park. A pilot campaign was conducted in the summer of 2018 in Rembrandt park in Amsterdam and insights from the citizen-driven observations were shared with the Department of Planning and Sustainability of Amsterdam

The presence and characterization of a virF gene on Agrobacterium vitis Ti plasmids

Microbial Biotechnolog

The Bases of Crown Gall Tumorigenesis

International audienc

Interaction of the virulence protein VirF of agrobacterium tumefaciens with plant homologs of the yeast Skp1 protein

AbstractThe infection of plants by Agrobacterium tumefaciens leads to the formation of crown gall tumors due to the transfer of a nucleoprotein complex into plant cells that is mediated by the virulence (vir) region–encoded transport system (reviewed in [1–5]). In addition, A. tumefaciens secretes the Vir proteins, VirE2 and VirF, directly into plant cells via the same VirB/VirD4 transport system [6], and both assist there in the transformation of normal cells into tumor cells. The function of the 22 kDa VirF protein is not clear. Deletion of the virF gene in A. tumefaciens leads to diminished virulence [7, 8] and can be complemented by the expression of the virF gene in the host plant. This finding indicates that VirF functions within the plant cell [8]. Here, we report that the VirF protein is the first prokaryotic protein with an F box by which it can interact with plant homologs of the yeast Skp1 protein. The presence of the F box turned out to be essential for the biological function of VirF. F box proteins and Skp1p are both subunits of a class of E3 ubiquitin ligases referred to as SCF complexes. Thus, VirF may be involved in the targeted proteolysis of specific host proteins in early stages of the transformation process