Biology subjects

Rosenkranz, M.

Publications and source records attributed to Rosenkranz, M..

6 recordsLinked to original sources

bioRxiv2024

Deciphering plant-beneficial fungal interactions: Unravelling metabolic diversity that underpins communication between Laccaria bicolor and Trichoderma

With over 250 known species, the genus Trichoderma (Ascomycota, Hypocreaceae) is found in various soils, on plant surfaces and as plant endophytes. While Trichoderma species are known as mycoparasites, their antagonistic behaviour can also negatively affect other beneficial fungi, such as mycorrhizal fungi. To gain insight into the metabolic signals involved in the interactions between the ectomycorrhizal fungus (ECM) Laccaria bicolor (Basidomycota, Hydnangiaceae), and different mycoparasitic Trichoderma spp. (T. harzianum strains WM24a1, MS8a1 and ES8g1, and T. atrobrunneum), we performed in vitro dual-confrontation experiments. We studied the volatile organic compounds (VOCs), hyphal metabolomes and soluble metabolites released by each of the fungi in various co-cultivation scenarios. The results revealed an altered growth of the mycelia depending on the degree of contact: When Trichoderma spp. and L. bicolor shared only the same headspace, Trichoderma spp. growth was at least partially inhibited, whereas in direct contact the growth of L. bicolor was impaired. Distinct strain- and species-specific changes in hyphal metabolites, in exudates and volatile emission were revealed from each of the studied fungi. We identified both core metabolite profiles and interaction-specific metabolic responses that were related to carbohydrate, lipid, nucleotide, energy and amino acid metabolisms. Volatile and soluble metabolites revealed temporal and spatial adjustments in dual cultures compared to solitary cultures, suggesting rapid contact-dependent adaptations and demonstrating the dynamic communication mechanisms between Trichoderma spp. and the ECM. These results suggest a central role for both emitted and secreted fungal metabolites in the fungal non-self-recognition and in interaction with each other.

microbiology↗

bioRxiv2024

Connectome predictive modeling of trait mindfulness

IntroductionTrait mindfulness refers to ones disposition or tendency to pay attention to their experiences in the present moment, in a non-judgmental and accepting way. Trait mindfulness has been robustly associated with positive mental health outcomes, but its neural underpinnings are poorly understood. Prior resting-state fMRI studies have associated trait mindfulness with within- and between-network connectivity of the default-mode (DMN), fronto-parietal (FPN), and salience networks. However, it is unclear how generalizable the findings are, how they relate to different components of trait mindfulness, and how other networks and brain areas may be involved. MethodsTo address these gaps, we conducted the largest resting-state fMRI study of trait mindfulness to-date, consisting of a pre-registered connectome predictive modeling analysis in 367 adults across three samples collected at different sites. ResultsIn the model-training dataset, we did not find connections that predicted overall trait mindfulness, but we identified neural models of two mindfulness subscales, Acting with Awareness and Non-judging. Models included both positive networks (sets of pairwise connections that positively predicted mindfulness with increasing connectivity) and negative networks, which showed the inverse relationship. The Acting with Awareness and Non-judging positive network models showed distinct network representations involving FPN and DMN, respectively. The negative network models, which overlapped significantly across subscales, involved connections across the whole brain with prominent involvement of somatomotor, visual and DMN networks. Only the negative networks generalized to predict subscale scores out-of-sample, and not across both test datasets. Predictions from both models were also negatively correlated with predictions from a well-established mind-wandering connectome model. ConclusionsWe present preliminary neural evidence for a generalizable connectivity models of trait mindfulness based on specific affective and cognitive facets. However, the incomplete generalization of the models across all sites and scanners, limited stability of the models, as well as the substantial overlap between the models, underscores the difficulty of finding robust brain markers of mindfulness facets.

neuroscience↗

bioRxiv2024

Sound perception in realistic surgery scenarios: Towards EEG-based auditory work strain measures for medical personnel.

Surgical personnel face various stressors in the workplace, including environmental sounds. Mobile electroencephalography (EEG) offers a promising approach for objectively measuring how individuals perceive sounds. In this study, we utilized mobile EEG to explore how a realistic soundscape is perceived during simulated laparoscopic surgery. To examine the varying demands placed on personnel in different situations, we manipulated the cognitive demand during the surgical task, using a memory task. To assess responses to the soundscape, we calculated event-related potentials for distinct sound events and temporal response functions for the ongoing soundscape. Although participants reported varying degrees of demand under different conditions, no significant effects were observed on surgical task performance or EEG parameters. However, changes in surgical task performance and EEG parameters over time were noted, while subjective results remained consistent over time. These findings highlight the importance of using multiple measures to fully understand the complex relationship between sound processing and cognitive demand. Furthermore, in the context of combined EEG and audio recordings in real-life scenarios, sparse representations of the soundscape have advantages over more detailed representations. Our results indicate that both types of representations are equally effective in eliciting neural responses. Overall, this study marks a significant step towards objectively investigating sound processing in applied settings.

neuroscience↗

bioRxiv2024

Lifestyle-specific responses of Trichoderma spp. in mycoparasitic confrontations and implications for biocontrol of Populus x canescens

O_LITrichoderma spp. are gaining popularity in agriculture and forestry due to their multifaceted roles in promoting plant growth through e.g. nutrient translocation, hormone production, induction of plant systemic resistance, but also direct antagonism of other fungi. However, the mycotrophic nature of the genus bears the risk of possible interference with other native plant-beneficial fungi, such as ectomycorrhiza, in the rhizosphere. Such interference could yield unpredictable consequences for the host plants of these ecosystems. C_LIO_LIWe investigated whether Trichoderma spp. can differentiate between beneficial ectomycorrhizal fungi (represented by Laccaria bicolor and Hebeloma cylindrosporum) and pathogenic fungi (represented by Fusarium graminearum and Alternaria alternata) in different confrontation scenarios, including a newly developed olfactometer "race tube"-like system. C_LIO_LIUsing two independent species, T. harzianum, and T. atrobrunneum, with plant-growth-promoting and immune-stimulating properties towards Populus x canescens, our study revealed robustly accelerated growth towards phytopathogens, while showing a contrary response to ectomycorrhizal fungi. Transcriptomic analyses identified distinct genetic programs during interaction corresponding to the lifestyles, emphasizing the expression of mycoparasitism-related genes only in the presence of phytopathogens. C_LIO_LIThe findings reveal a critical mode of fungal community interactions belowground and suggest that Trichoderma spp. can distinguish between fungal partners of different lifestyles already at a distance. C_LI

microbiology↗

bioRxiv2022

Breadth of Fc-mediated effector function delineates grades of clinical immunity following human malaria challenge

Controlled human malaria challenge studies in semi-immune volunteers provide an unparalleled opportunity to robustly identify mechanistic correlates of protection. We leveraged this platform to undertake a head-to-head comparison of seven functional antibody assays that are relevant to immunity against the erythrocytic merozoite stage of Plasmodium falciparum. Fc-mediated effector functions were strongly associated with protection from clinical symptoms of malaria and exponential parasite multiplication while the gold standard growth inhibition assay was not. The breadth of Fc-mediated effector function clearly discriminated grades of clinical immunity following challenge. These findings present a paradigm shift in the understanding of the mechanisms that underpin immunity to malaria and have important implications for vaccine development.

immunology↗

bioRxiv2022

Investigating the attentional focus to workplace-related soundscapes in a complex audio-visual-motor task using EEG

In demanding work situations (e.g., during a surgery) the processing of complex soundscapes varies over time and can be a burden for medical personnel. Here we study, using mobile electroencephalography (EEG), how humans process workplace-related soundscapes while performing a complex audio-visual-motor task (3D Tetris). Specifically, we wanted to know how the attentional focus changes the processing of the soundscape as a whole. Participants played a game of 3D Tetris in which they had to use both hands to control falling blocks. At the same time, participants listened to a complex soundscape, similar to what is found in an operating room (i.e., sound of machinery, people talking in the background, alarm sounds, and instructions). In this within-subject design, participants had to react to instructions (e.g., "place the next Block in the upper left corner") and to sounds depending on the experimental condition, either to a specific alarm sound originating from a fixed location or to a beep sound that originated from varying locations. Attention to the alarm reflected a narrow attentional focus, as it was easy to detect and most of the soundscape could be ignored. Attention to the beep reflected a wide attentional focus, as it required the participants to monitor multiple different sound streams. Results show the robustness of the N1 and P3 event related potential response during this dynamic task with a complex auditory soundscape. Furthermore, we used temporal response functions to study auditory processing to the whole soundscape. This work is a step towards studying workplace-related sound processing in the operating room using mobile EEG.

neuroscience↗