Biology subjects

Rosenkranz, M.

Publications and source records attributed to Rosenkranz, M..

12 recordsLinked to original sources

bioRxiv2026

Fungal volatiles drive lifestyle-dependent, systemic metabolic reprogramming in poplar

O_LIRationale: Although trees encounter diverse fungal communities, it is unclear how they adjust their physiology in response to fungal ecological strategies before physical contact. We tested whether volatile organic compounds (VOCs) emitted by fungi are sufficient to induce systemic, lifestyle-consistent metabolic states in poplar roots and leaves. C_LIO_LIMethods: Populus x canescens roots were exposed to VOCs from a pathogen (Heterobasidion annosum), a saprotroph (Postia placenta) or an ectomycorrhizal mutualist (Laccaria bicolor) for six weeks in a contact-free pot-in-pot system. Untargeted LC-MS metabolomics characterized VOC-induced metabolic reprogramming in roots and leaves. C_LIO_LIKey results: Fungal VOC exposure alone reconfigured the metabolomes of roots and leaves, with strong discrimination between treatments despite belowground exposure. Poplar revealed a shared VOC-responsive component, but also fungus-specific programmes: pathogen VOCs produced a suppression-dominated systemic phenotype; saprotroph VOCs promoted lipid-centred metabolic activation; and mutualist VOCs elicited restrained, compatibility-consistent shifts with targeted pathway modulation. C_LIO_LIMain conclusion: Volatile-mediated surveillance allows trees to anticipate fungal lifestyle-associated cues and adjust systemic metabolism before physical contact occurs. This links airborne fungal cues to whole-plant physiological configuration and extends plant-fungal recognition beyond contact-dependent mechanisms. C_LI One-sentence summaryVolatile-mediated surveillance allows trees to anticipate fungal lifestyle and adjust systemic metabolism before physical contact occurs.

plant biology↗

bioRxiv2025

Volatile cues from pathogenic, mutualistic and saprotrophic fungi cause specific, fungus-dependent responses in poplar

Plants are exposed to complex interactions with belowground organisms, yet how they differentiate between mutualistic and pathogenic fungi before physical contact remains largely unknown. We exposed the roots of young Populus x canescens to volatile organic compounds (VOCs) emitted by either a pathogenic (Heterobasidion annosum), a saprotrophic (Postia placenta), or an ectomycorrhizal (Laccaria bicolor) fungus. VOC analysis of the shared rhizosphere headspace and leaf emissions revealed that poplar plants could perceive and respond to fungal identity solely through airborne cues. The root-zone headspace contained fungus-specific sesquiterpene fingerprints that remained similar after three and six weeks of co-cultivation: Pathogen-derived VOCs induced constant high sesquiterpene emissions from the root-zone, whereas mycorrhiza caused low but targeted emissions of specific sesquiterpenes. In contrast, saprotrophic VOCs caused a temporal shift in root-zone VOC pattern, with increased sesquiterpene emissions after six weeks. Fungal VOC exposure also altered leaf VOC emissions, enriching alkanes, esters and monoterpenes. Initially, leaf VOC emissions were fungal lifestyle-specific but they converged over time, indicating systemic signal integration of belowground signals. These findings demonstrate that trees can discriminate "friend-versus-foe" through VOCs alone, extending pattern-recognition theory beyond contact-dependent cues. Multivariate analyses suggested organ-specific chemical strategies: roots function as chemosensors decoding fungal volatilomes, while systemic adjustments shape aboveground VOC profiles. Understanding the plant response to fungal VOCs may offer potential for developing early pathogen diagnostics and further elucidate the volatile-mediated plant-fungal interactions.

plant biology↗

bioRxiv2025

Neural response attenuation for shorter inter-onset intervals between sounds in a natural soundscape

Sensory attenuation of auditory evoked potentials (AEPs), particularly N1 and P2 components, has been widely demonstrated in response to simple, repetitive stimuli sequences of isolated synthetic sounds. It remains unclear, however, whether these effects generalize to complex soundscapes where temporal and acoustic features vary more broadly and dynamically. In this study, we investigated whether the inter-onset interval (IOI), the time between successive sound events, modulates AEP amplitudes in a complex auditory scene. We derived acoustic onsets from a naturalistic soundscape and applied temporal response function (TRF) analysis to EEG data recorded from normal hearing listeners. Our results showed that shorter IOIs are associated with attenuated N1 and P2 amplitudes, replicating classical adaptation effects in a naturalistic soundscape. These effects remained stable when controlling for other acoustic features such as intensity and envelope sharpness and across different TRF model specifications. Integrating IOI information into predictive modelling revealed that neural dynamics were captured more effectively than simpler onset models when training data were matched. These findings highlight the brains sensitivity to temporal structure even in highly variable auditory environments, and show that classical lab findings generalize to naturalistic soundscapes. Our results underscore the need to include temporal features alongside acoustic ones in models of real-world auditory processing. HighlightsO_LINeural responses (N1, P2) to sound events are attenuated when inter-onset intervals are short, replicating classic attenuation effects in a naturalistic soundscape. C_LIO_LIAutomatic onset detection from complex, ecologically valid soundscapes enables fine-grained analysis of temporal auditory dynamics. C_LIO_LIThese findings highlight that temporal sensitivity in auditory processing persists even in highly variable, real-world acoustic environments. C_LI

neuroscience↗

bioRxiv2025

The effect of task demand on EEG responses to irrelevant sound and speech in simulated surgical environments.

1Complex soundscapes in high-stakes environments, such as the operating room (OR), are characterized by a variety of overlapping auditory stimuli and present significant challenges for personnel, particularly during periods of high demand. This study investigates how task demand and an OR soundscape including irrelevant speech, influence perceived work-load, surgical performance, and auditory processing in a simulated surgical environment, using mobile electroencephalography (EEG). Participants performed two simulated surgical tasks, namely peg transfer and suturing, representing a low-demand and high-demand task, respectively. The tasks were performed under two sound conditions: An OR soundscape was presented with irrelevant speech or alone. Neural responses to transient and continuous auditory stimuli were analyzed using event-related potentials (ERPs) and temporal response functions (TRFs), respectively. Results showed that irrelevant speech increased self-reported workload and distraction. EEG analyses revealed reduced neural responses to transient sounds and irrelevant speech under high task demand, reflecting early-stage sensory filtering of auditory distractions. Notably, an inverse relationship was observed between neural responses to speech and self-reported workload, indicating that the speech responses may serve as a marker for perceived workload. Overall, this study demonstrates the potential of EEG to assess irrelevant sound processing in realistic work-like settings and highlights the critical role of task demand in modulating neural responses and self-reported workload to soundscapes.

neuroscience↗

bioRxiv2025

Volatile-Mediated Plant Defense Networks: Field Evidence for Isoprene as a Short-Distance Immune Signal

Isoprene, the most abundant hydrocarbon emitted by vegetation, protects photosynthesis against oxidative and thermal stress and significantly impacts atmospheric chemistry. While laboratory studies suggest a role for isoprene in plant defense, its function in plant-plant communication under natural conditions remains unclear. Here, we demonstrate that isoprene acts as a signaling molecule, triggering systemic immune responses in neighboring plants against bacterial pathogens under field conditions. We established an experimental system using wild-type and transgenic silver birch (Betula pendula) lines engineered to emit varying levels of isoprene. Over two growing seasons, we examined the effects of birch-emitted volatile organic compounds on neighboring Arabidopsis thaliana, including wild-type and immune signaling mutants (llp1: legume lectin-like protein 1; jar1: jasmonate resistant 1). Isoprene emission rates positively correlated with systemic resistance in receiver plants, with higher emissions enhancing inhibition of Pseudomonas syringae growth. This immune response occurred independently of jasmonate signaling but required functional LLP1, suggesting a specific recognition pathway. By combining Arabidopsis mutant responses with birch volatile profiles, we confirmed that isoprene, rather than other terpenoids, mediates this effect. These findings reveal an unrecognized ecological function of isoprene as an airborne immune signal, establishing transgenic birch as a robust model for studying volatile-mediated plant defense networks in natural environments. Our results provide new insights into the molecular mechanisms underlying plant volatile perception and expand our understanding of chemical communication in terrestrial ecosystems. Significance StatementIsoprene, the most abundant volatile organic compound released by plants, protects against abiotic stress. Here, we demonstrate that isoprene also functions under ambient atmosphere as a short-distance immune signal, enhancing neighboring plants resistance to bacterial pathogens. This finding reveals a putative ecological role of isoprene in plant defense networks and suggests strategies for sustainable agriculture and forest management under environmental stress.

plant biology↗

bioRxiv2024

From Beeps to Streets: Unveiling Sensory Input and Relevance Across Auditory Contexts

This study investigates the neural basis of sound perception in everyday life using EEG data recorded in an office-like environment over 3.5 hours. We investigated how contextual factors such as personal relevance, task complexity and stimulus properties influence auditory processing in ecologically valid settings. By systematically increasing the complexity of acoustic scenes and tasks, we analysed changes in neural responses, particularly in the N100 and P300 components. Our results show that while the P300 is a stable marker of attention in both isolated sounds and complex soundscapes, the N100 is more sensitive to task complexity and environmental factors. This highlights the importance of context in shaping auditory perception. Furthermore, our results suggest that laboratory-based findings can be partially generalised to real-world settings, although task demands significantly influence neural markers. These findings provide new opportunities to study sound perception in naturalistic settings, without sacrificing the control typically afforded by laboratory studies.

neuroscience↗

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↗