Vanda Adamkova

The ERF family is one of the largest families of plant-specific transcription factors, controlling diverse developmental processes and stress responses. Extensive gene duplication and redundancy in flowering plants have generated large ERF repertoires, complicating comparisons of ERF function across land-plant lineages. How ERF transcription factor repertoires and their functions have evolved across land plants remains poorly understood. Here, we reconstruct the phylogenetic relationships and expansion of ERF transcription factors across land plants and exploit the compact ERF repertoire of the model liverwort Marchantia polymorpha to investigate their functional diversification. Systematic gain-of-function analysis reveals that different clades of ERFs can drive distinct cell fate and reprogramming outcomes in Marchantia, in addition to stress-related functions. Interestingly, we found that Mp ERF2 , the sole Group I ERF in Marchantia, phylogenetically related to the WIND clade, promotes rhizoid cell differentiation. This contrast with the role of the WIND clade in wound-induced regeneration in Arabidopsis. Heterologous expression of At WIND1 in Marchantia was also capable of inducing rhizoid formation, supporting the hypothesis that this reprogramming capacity is conserved at the protein level. On the other hand, loss of Mp ERF2 reduced rhizoid coverage but did not significantly impair regeneration. These findings provide an evolutionary framework for understanding the functional evolution of ERF transcription factors and how conserved transcriptional regulators are co-opted into novel developmental programs during the radiation of land plants.

Upon activation, plant nucleotide-binding leucine-rich repeat (NLR) immune receptors are known to assemble into oligomeric resistosomes that insert into the plasma membrane, forming calcium (Ca ²⁺ )–permeable channels and triggering immunity. Here, we found that the RPW8-like coiled-coil NLR (CC _R -NLR) N requirement gene 1 (NRG1) primarily targets organelles instead of the plasma membrane. Unlike canonical CC-NLRs, activated NRG1 accumulated at the chloroplast envelope and channeled stromal Ca ²⁺ into the cytosol. AlphaFold modeling of the NRG1 resistosome revealed an unusually long amino-terminal membrane-insertion structure that could span the double membrane of the chloroplast. Nanobody-mediated relocalization showed functional membrane specificity: Chloroplast trapping abolished activity of the canonical helper CC-NLR NRC4 but not NRG1. NRG1 orthologs, from nonflowering lineages to angiosperms, targeted chloroplasts, suggesting that organelle-centered defense dates back at least ~360 million years. We propose that CC-NLR diversification has enabled compartment-specific immune signaling to capture diverse Ca ²⁺ stores.

Communication between cellular organelles is essential for mounting effective innate immune responses. The transport of organelles to pathogen penetration sites and their assembly around the host membrane, which delineates the plant-pathogen interface, are well-documented. However, whether organelles associate with these specialized interfaces, and the extent to which this process contributes to immunity, remain unknown. Here, we discovered defense-related membrane contact sites (MCS) comprising a membrane tethering complex between chloroplasts and the extrahaustorial membrane (EHM) surrounding the haustorium of the pathogen Phytophthora infestans in Nicotiana benthamiana. The assembly of this complex involves association between the chloroplast outer envelope protein CHLOROPLAST UNUSUAL POSITIONING 1 (CHUP1) and its plasma membrane-associated partner KINESIN-LIKE PROTEIN FOR ACTIN-BASED CHLOROPLAST MOVEMENT 1 (KAC1). Our biochemical assays revealed that CHUP1 and KAC1 interact, and infection cell biology assays demonstrated their co-accumulation in foci where chloroplasts contact the EHM. Genetic depletion of CHUP1 or KAC1 reduces the focal deposition of callose around the haustorium without affecting other core immune processes. Our findings suggest that the chloroplast-EHM attachment complex promotes plant focal immunity, revealing key components and their potential roles in the deposition of defense materials at the pathogen interface. These results advance our understanding of organelle-mediated immunity and highlight the significance of MCS in plant-pathogen interactions.

Urinary tract infections (UTIs) are one of the most common bacterial diseases both in communities and in hospitalized patients, and at the same, time they are one of the most common indications for the use of antibiotics. UTI guidelines are generally available nationally or internationally, but they do not address all aspects of UTI treatment for different patient cohorts, age, gender, or comorbidities. The aim of the study was to point out the importance of stratified cumulative antibiograms at the level of individual health care facilities and the significant differences between epidemiological data, not only at the national level, but also at the local level. Our study analyses data from 383 patients with UTIs from a hospital department, General University Hospital (GUH), and 272 patients from an outpatient medical facility, Urocentrum (UC). This analysis focuses on the most common UTI causative agent, Escherichia coli, its representation as the causative agent of UTI in patients with complicated acute cystitis (N30), and its representation in complicated acute cystitis in patients with prostate cancer (C61). In addition to the frequency of occurrence, a sub-analysis of the incidence of resistance of E. coli to commonly used antibiotics by age, gender, diagnosis, and medical facility was performed. Results: The most common causative agent of UTI was E. coli. In patients with N30, it was 70% in GUH and 54% in UC, but in oncological patients with UTI, it was only 39% and 35%, respectively. In patients with UTI in C61, there was a significant difference in susceptibility of E. coli between individual health care facilities. Lower resistance was found in UC opposite to GUH isolates in ampicillin, with 29.8% vs. 65%, p = 0.001; amoxicillin/clavulanic acid, with 8.5% vs. 30%, p = 0.01; with 2.1% vs. 17.5% in pivmecillinam, p = 0.01; with 10.6% vs. 37.5% in co-trimoxazole, p = 0.003; and ciprofloxacin, with 10.6% vs. 30%, p = 0.04. The study shows significant differences in the sensitivity of urinary E. coli isolates in patients in relation to age, gender, medical devices, and the presence of comorbidities.

Upon activation, plant NLR immune receptors are known to assemble into oligomeric resistosomes that insert into the plasma membrane, forming Ca ²⁺ -permeable channels and triggering immunity. Here, we show that the RPW8-like coiled-coil (CC _R -) NLR NRG1 primarily targets organelles instead of the plasma membrane. Unlike canonical CC-NLRs, activated NRG1 accumulates at the chloroplast envelope and channels stromal Ca ²⁺ into the cytosol. AlphaFold modeling of the NRG1 resistosome reveals an unusually long N-terminal membrane-insertion structure that would span the double chloroplast membranes. Nanobody-mediated relocalization shows functional membrane specificity: chloroplast trapping abolishes activity of the canonical helper CC-NLR NRC4 but not NRG1. NRG1 orthologs, from non-flowering lineages to angiosperms, target chloroplasts, suggesting that organelle-centered defense dates back to at least ∼360 million years. We propose that coiled-coil NLR diversification has enabled compartment-specific immune signaling to capture diverse Ca ²⁺ stores.

Streptococcus pyogenes, group A streptococci (GAS) bacteriaemia, is a life-threatening infection with high mortality, requiring fast diagnosis together with the use of appropriate antibiotic therapy as soon as possible. Our study analysed data from 93 patients with GAS bacteraemia at the General University Hospital in Prague between January 2006 and March 2024. In the years 2016–2019 there was an increase in GAS bacteraemia. Mortality in the period 2006–2019 was 21.9%; in the period 2020–2024, the mortality increased to 41.4%, p = 0.08. At the same time, in the post-2020 period, the time from hospital admission to death was reduced from 9.5 days to 3 days. A significant predictor of worse outcome in this period was high levels of procalcitonin, >35.1 µg/L (100% sensitivity and 82.35% specificity), and lactate, >5 mmol/L (90.91% sensitivity and 91.67% specificity). Myoglobin was a significant predictor in both compared periods, the AUC was 0.771, p = 0.044, and the AUC was an even 0.889, p ≤ 0.001, respectively. All isolates of S. pyogenes were susceptible to penicillin, and resistance to clindamycin was 20.3% from 2006–2019 and 10.3% in 2020–2024. Appropriate therapy was initiated in 89.1%. and 96.6%, respectively. We hypothesise that the increase in mortality after 2020 might be due to a decrease in the immune status of the population.

When a plant detects a pathogen, chloroplasts terminate photosynthetic activity and uptake vital roles in the immune system to help stave off infection, including the production of defense hormone precursors and antimicrobial reactive oxygen species. Additionally, chloroplasts associate with the nucleus and produce greater numbers of tubular extensions called stromules during immune challenge. We previously showed that during infection by the potato blight pathogen Phytophthora infestans, chloroplasts accumulate at the pathogen haustoria, hyphal extensions that are accommodated within the host cell. However, the extent to which chloroplast positioning around haustoria, or at the nucleus, contributes to immunity during infection remains unknown. Here we show a striking increase in the susceptibility to P. infestans of Nicotiana benthamiana CRISPR knock-out lines lacking the chloroplast movement and anchoring gene, CHLOROPLAST UNUSUAL POSITIONING 1 (CHUP1). However, the positioning of chloroplasts around the haustorium or nucleus is not impaired in the absence of CHUP1. Further, loss of CHUP1 leads to an extreme clustering of chloroplasts around the nucleus in the presence and absence of infection, showing that greater chloroplast-nucleus association does not necessarily equate to more robust immunity. While plants lacking CHUP1 have reduced basal stromules, they are still able to induce stromules following immune stimulation, indicating that multiple populations of stromules exist. Lastly, we found that CHUP1 is required for proper deposition of callose - a cell wall material implicated in pathogen penetration resistance - around P. infestans haustorium, but not for other core immune processes. Our results implicate chloroplasts in plant focal immunity and point to a key role of CHUP1 in facilitating the deposition of defense material at the pathogen interface.