In order to keep personal contacts to a minimum, it is strongly recommended to work from home as much as possible (Allgemeinverfügung des Landes SA). That means that experimental research of the RTG groups is limited to obligatory processes to protect yourself and your fellow human beings at least until 5 April 2020.

To support PhD students who are now impaired in their work the Deutsche Forschungsgemeinschaft DFG offered the opportunity to extend projects of the RTG (DFG-Schreiben). To get more information to the effects of the coronavirus pandemic on the work of the DFG visit: DFG website.

The spread of the covid-19 virus impacts greatly on campus life (uni-halle.de/coronavirus/) and now also on our RTG activities. The research by PhD students is (so far) not affected. Research is going on. However, in line with the notion to minimize all social interactions to limit the spread of the virus, all group activities of the RTG, including weekly seminars and our planned Retreat, are suspended until further notice.

Claire Letanneur, a very kind PhD student from the Université du Québec à Trois-Rivières, visited the lab of Dr. Martin Schattat for two month. Here she continued working on the host-pathogen interaction and the signaling of effector proteins. Today she will give her final report with the title “Melampsora larici-populina host-specific effector homologs: Do they have a role to play in the infection process?” to our RTG members. Two month went by too fast…. All best for the future!

Now it’s fixed: At the end of March we will have our first Retreat in the LEUCOREA – Lutherstadt Wittenberg. PIs and PhD students will present their projects and progress in talks and posters. We can look forward to a lively scientific exchange and constructive discussions.

We proudly announce that our next RTG 2498 guest will be Dr. Marie Barberon from the Université de Genève, Switzerland. On the 26 November she will personally visit some RTG-groups and talk to the PIs and PhD-students about recent research. In the evening she will give a lecture about “Plasticity of root permeability for nutrient acquisition” as a part of the Halle Plant Science Colloquium. We’re really looking forward to meeting her.

Abstract: Plant roots forage the soil to acquire water and nutrients for growth and development. This function is closely linked to their anatomy: water and nutrients move radially through the concentric layers of epidermis, cortex, and endodermis before entering the vasculature. This arrangement allows for three uptake scenarios: the “symplastic pathway”, where the outer cells actively take up nutrients, which are then transported from cell to cell through plasmodesmata; the “apoplastic pathway”, where nutrients are transported in the apoplast and blocked by the endodermal apoplastic barrier (Casparian strips); and the “coupled trans-cellular pathway”, where nutrients are transported sequentially from one cell to another by polarized influx and efflux carriers and are barred by the endodermal diffusion barrier (suberin lamellae). My group aims to functionally characterize these pathways for nutrient acquisition by a combination of physiology, cell biology and developmental approaches. We are particularly interested in suberin lamellae and plasmodesmata function and regulations for nutrient acquisition.

On Tuesday, 05 November the RTG 2498 welcomes Prof. Ralph Hückelhoven from TUM Weihenstephan in Freising. His research focuses the biological and molecular causes of plant diseases. In Halle he will give a talk as part of the Halle Plant Science Colloquium at 17:00  about “Mechanisms of ROP GTPase signalling in plant disease susceptibility“. We’re looking forward to meeting him and learn more about pathogen-host-interactions on the molecular level.

Abstract: Plant diseases and resistance to fungal pathogens are often considered as two sides of the same coin. In this context, disease is the result of the failure of defense due to a lack of pathogen recognition or suppression of host defenses or both. However, in case of long-lasting biotrophic interactions, it may be insufficient for the pathogen to just avoid recognition and suppress defense. Instead, a successful biotroph may take advantage of host susceptibility factors, which actively support the pathogen. The barley ROP (RHO OF PLANTs) GTPase RACB is a susceptibility factor in interaction with the barley powdery mildew fungus Blumeria graminis f. sp. hordei (Bgh). In healthy plants, RACB is involved in cell polarity and cytoskeleton organization and we hypothesize that Bgh profits from these functions in effector triggered susceptibility. Indeed, a non-conventional effector of Bgh interacts with RACB and destabilizes microtubules. We now identified further possible upstream and downstream interaction partners of RACB by yeast two hybrid assays, co-immunoprecipitation and FRET FLIM assays. This identified another possible effector of Bgh, several scaffold proteins that might link RACB to downstream executer pathways and proteins of membrane signalling and organization. Several of those RACB-interaction partners show the potential to support susceptibility to Bgh and display RACB-dependent subcellular localization at sites of fungal invasion or at microtubules. Together, data strongly suggest that RACB is a central hub in a network of susceptibility factors that is directly´addressed by fungal effector proteins. Additionally, RACB could represent a susceptibility factor, which does not control host immunity but rather supports processes, which are required by Bgh during accommodation of the haustorium.

The RTG 2498 invited Prof. Jim Whelan from LaTrobe University, Australia to give a talk as part of the Halle Plant Science Colloquium on Tuesday, 08 October at 17:00. He is an outstanding expert in the field of plant mitochondrial biogenesis and with his talk about “Mitochondrial Signaling – Specific and Shared Pathways” he perfectly supports our RTG. We’re really looking forward to meeting him.

Abstract: To achieve functional plasticity, mitochondrial activity needs to be coordinated on the cellular level via anterograde and retrograde signaling pathways, that control mitochondrial biogenesis from seed germination to senescence. At a transcriptional level, the integration of these mitochondrial pathways with those in chloroplasts, hormonal and environmental signalling pathways is being uncovered. At a post-transcriptional level, the regulation of various cellular functions via controlling RNA and protein turnover, protein trafficking and enzyme activity, also impact mitochondrial function. Also, recent studies suggest post-translational regulation of mitochondrial retrograde signaling. Together these studies show that mitochondria not only respond to stress, but also act as a sensors for cellular metabolism, and inputs from mitochondria re-program cellular processes from mitotic activity to cell death to optimise plant growth.