Biology subjects

Brunner, F.

Publications and source records attributed to Brunner, F..

3 recordsLinked to original sources

bioRxiv2025

Plant Growth Promoting fungal endophyte Colletotrichum tofieldiae Ct0861 reduces mycotoxigenic Aspergillus fungi in maize grains

1.BackgroundMaize (Zea mays L.) is a globally critical crop that faces numerous challenges, including contamination by mycotoxigenic fungi such as Aspergillus spp., which threaten food safety and marketability. This study evaluates the potential of the fungal endophyte Colletotrichum tofieldiae strain Ct0861 as a bioinoculant to enhance maize productivity and investigates its impact on the maize-associated bacterial and fungal microbiomes. ResultsField trials showed that Ct0861 treatment enhances biomass and yield compared to controls, irrespective of the application method assayed (seed or spray application). Comprehensive microbiome profiling across soil, rhizosphere, roots, leaves, and grains revealed that Ct0861 inoculation induced subtle, compartment-specific effects on microbial diversity and composition, with similar effects for the two application methods used. Fungal alpha-diversity in grains was significantly reduced, while beta-diversity analyses showed localized shifts, particularly in soil and grain-associated microbial communities. Despite these changes, the core microbiome assemblages remained stable, indicating minimal alteration to the broader microbiome structure. Remarkably, Ct0861 significantly reduced the prevalence of Aspergillus spp. in maize grains, as confirmed by controlled infection assays. This reduction resulted in lower aflatoxin levels, demonstrating the biocontrol potential of Ct0861. ConclusionThese findings underscore Ct0861s dual benefits in enhancing crop yield and safety reducing fungal mycotoxin contamination. Further studies are necessary to elucidate the underlying mechanisms and expand its application across diverse agroecosystems.

microbiology↗

bioRxiv2024

Maize associated bacterial and fungal microbiomes show contrasting conformation patterns that are resilient to water availability

Plant-associated microorganisms can help crops to alleviate water stress and increase the resilience of agricultural ecosystems to climate change. However, we still lack knowledge on the dynamics of bacterial and fungal microbial kingdoms within the soil and plant microbiomes and the response of these communities to different conditions such us, for example, water restrictions. This information is essential for the development of microbiome-based solutions to improve crop resilience to stressors associated to climate change. In this work, we explored: i) the conformation of the bacterial and fungal assemblages of different soil and plant compartments (bulk soil, rhizosphere, roots, leaves and grains) along the crop cycle of maize in an open field trial; and ii) the effect of water restriction on the maize microbiome comparing optimal irrigation with a 30% reduction of water supply. Our results show that microbial communities are highly structured along soil and plant compartments, with contrasting patterns for bacteria and fungi that were intensified towards the end of the plant cycle. Root showed the most differentiated bacterial assemblage while fungi conformed a very distinct community in the leaf, suggesting a relevant contribution of aerial fungal propagules to the microbiome of this plant organ. Despite the reductions in plant growth and yield, the microbiome of limited-watered plants did not show severe alterations. Still, significant impacts were observed within compartments, being fungi more responsive to limited watering than bacteria. Network analysis suggest that bacteria and fungi may play different roles in the shifts observed under water stress.

microbiology↗

bioRxiv2020

Quantifying multivariate genotype-by-environment interactions, evolutionary potential and its context-dependence in natural populations of the water flea, Daphnia magna.

Genotype-by-environment interactions (G x E) underpin the evolution of plastic responses in natural populations. Theory assumes that G x E interactions exist but empirical evidence from natural populations is equivocal and difficult to interpret because G x E interactions are normally univariate plastic responses to a single environmental gradient. We compared multivariate plastic responses of 43 Daphnia magna clones from the same population in a factorial experiment that crossed temperature and food environments. Multivariate plastic responses explained more than 30% of the total phenotypic variation in each environment. G x E interactions were detected in most environment combinations irrespective of the methodology used. However, the nature of G x E interactions was context-dependent and led to environment-specific differences in additive genetic variation (G-matrices). Clones that deviated from the population average plastic response were not the same in each environmental context and there was no difference in whether clones varied in the nature (phenotypic integration) or magnitude of their plastic response in different environments. Plastic responses to food were aligned with additive genetic variation (gmax) at both temperatures, whereas plastic responses to temperature were not aligned with additive genetic variation (gmax) in either food environment. These results suggest that fundamental differences may exist in the potential for our population to evolve novel responses to food versus temperature changes, and challenges past interpretations of thermal adaptation based on univariate studies.

evolutionary biology↗