Biology subjects

Berg, G.

Publications and source records attributed to Berg, G..

6 recordsLinked to original sources

bioRxiv2025

Plant sexual and asexual contributions to the seed microbiome

The seed microbiome plays a key role in the assembly of the plant microbiome, which has major impacts on plant functioning. Nonetheless, little is known about the origin of the seed microbiome. We investigated the relative contributions of two hypothesized transmission routes: sexual inheritance (via reproductive organs) and asexual inheritance (via the plant vascular system). To do that, we sampled shoot endophytes both before bloom and at seed maturity stages, apple flower ovaries and pollen sacs, and mature seeds from field-grown apple trees (Malus domestica BO_SCPLOWORKHC_SCPLOW. cv Gala Galaxy Selecta). We showed that bacterial richness, diversity and composition differ among tissue types, with shoots before bloom harboring a higher diversity than ovary and pollen. Source tracking revealed that both sexual (30.3%) and asexual (23.8%) pathways contributed to seed microbiome assembly, with shoots at seed maturity being the dominant source. Notably, a large proportion (49.5%) of the seed microbiome originated from unknown sources. Lastly, the transmission pathways significantly differed among bacterial genera, with Pseudomonas primarily linked to shoots, Rhizobacter to pollen and Burkholderia to the ovary. Insights into seed microbiome origin offers new opportunities to enhance seed health and crop productivity through microbiome-assisted breeding.

ecology↗

bioRxiv2025

Prosystemin-derived signals: bridging leaf microbiome dynamics and defense activation

AbstractThe use of plant-derived peptides as resistance inducers provides innovative and potentially environmentally friendly methods to safeguard crop health. Although their use is increasing rapidly, their broader impact, particularly on plant-associated microbiomes, remains underexplored. This study investigated the influence of a promising immunomodulatory peptide derived from the tomato defense protein prosystemin on the tomato phyllosphere microbiome. We applied the peptide via foliar spray biweekly to simulate common agricultural practices from the planting stage to two months post-germination. Using a shotgun metagenomics approach combined with qPCR, we identified bacterial communities of high abundance (up to 4.6 log10 bacterial 16S rRNA copies) and high diversity, mainly comprising Actino-, Alphaproteo- and Gammaproteobacteria, on all tomato leaves. The peptide treatment led to a significant and targeted shift in the bacterial community, characterized by reduced diversity and network complexity and species loss, i.e., Streptomyces. The enrichment was predominantly observed in bacterial genera such as Acinetobacter, Sphingobium, Sphingomonas, Brevundimonas, and Massilia, which are typically associated with improved plant growth and stress resilience. Intriguingly, shifts in both taxonomic and functional profile upon peptide application aligned with patterns typically observed during plant defense activation, involving jasmonic acid and related secondary metabolites. Members of the Sphingomonadaceae family, particularly Sphingobium yanoikuyae, have emerged as potential drivers of such microbial dynamics, likely adapting to plant upregulated defenses and potentially supporting its resilient phenotype. Overall, in addition to its well-established role in combating tomato pests and necrotrophic fungi, the prosystemin-derived peptide paves the way for disentangling peptide-induced resistance and its interplay with the plant microbiota.

plant biology↗

bioRxiv2024

"Tiny Biome Tales": a gamified review about the influence of lifestyle choices on the human microbiome

In the last two decades, new discoveries from microbiome research have changed our understanding of human health. It became evident that daily habits and lifestyle choices shape the human microbiome and ultimately determine health or disease. Therefore, we developed "Tiny Biome Tales" (https://microbiome.gamelabgraz.at/), a science pedagogy video game designed like a scientific review based exclusively on peer-reviewed articles, to teach about the influence of lifestyle choices on the human microbiome during pregnancy, early and adult life, and related health consequences. Despite the scientific character, it can be played by a broad audience. Here, we also present a scientific assessment, and showed that playing the game significantly contributed to knowledge gain. The innovative style of the "gamified review" represents an ideal platform to disseminate future findings from microbiome research by updating existing and adding new scenes to the game.

scientific communication and education↗

bioRxiv2024

Biological management, rather than chemical management, promotes the interaction between plants and their microbiome

In the face of climate change, developing sustainable agricultural practices to reduce the use of synthetic herbicides and pesticides is crucial. However, breeding for higher yields can lead to the decoupling of plant roots and beneficial rhizosphere microbes. In this study, we aim to identify potato cultivars with functional traits facilitating efficient interactions with the rhizosphere microbiome under various agricultural treatments in the field. With the results of profiling microbial communities with amplicon sequencing data of bacteria (16S rRNA gene fragments) and fungi (ITS2 region), a piecewise structural equation model was developed. This model explains the trade-off effects of agricultural management and potato cultivars on plant growth by affecting the rhizosphere microbiome. Furthermore, we highlight that plant cultivar and the rhizosphere microbiome together determine plant below-ground growth under biological management. In contrast, both components are found to be uncoupled under chemical and control management. Our study reveals the importance of considering microbiomes in the breeding process to achieve the goals of sustainable agriculture.

microbiology↗

bioRxiv2021

Buenos Aires, June 2021Inhibition of Mitochondrial Fission by Drp-1 Blockade by Short-Term Leptin and Mdvi-1 Treatment Improves White Adipose Tissue Abnormalities in Obesity and Diabetes

BackgroundObesity and type 2 diabetes are chronic diseases characterized by insulin resistance, mitochondrial dysfunction and morphology abnormalities. ObjectiveHerein, we investigated if dysregulation of mitochondrial dynamics and biogenesis is involved in an animal model of obesity and diabetes. MethodsThe effect of short-term leptin and mdivi-1 -a selective inhibitor of Drp-1 fission-protein- treatment on mitochondrial dynamics and biogenesis was evaluated in epididymal white adipose tissue (WAT) from male ob/ob mice. ResultsAn increase in Drp-1 protein levels and a decrease in Mfn2 and OPA-1 protein expression were observed with enhanced and sustained mitochondrial fragmentation in ob/ob mice compared to wt C57BL/6 animals (p<0.05). The content of mitochondrial DNA and mRNA expression of PGC-1 -both parameters of mitochondrial biogenesis- were reduced in ob/ob mice (p<0.05). Leptin and mdivi-1 treatment significantly increased mitochondrial biogenesis, improved fusion-to-fission balance and attenuated mitochondrial dysfunction, thus inducing white-to-beige adipocyte transdifferentiation. Measurements of glucose and lipid oxidation in adipocytes revealed that both leptin and mdivi-1 increase substrates oxidation while in vivo determination of blood glucose concentration showed decreased levels by 50% in ob/ob mice, almost to the wt level. ConclusionsPharmacological targeting of Drp-1 fission protein may be a potential novel therapeutic tool for obesity and type 2 diabetes.

molecular biology↗

bioRxiv2019

Unravelling native plant resistomes - The Sphagnum microbiome harbours versatile and novel antimicrobial resistance genes

The expanding antibiotic resistance crisis calls for a more in depth understanding of the importance of antimicrobial resistance genes (ARGs) in pristine environments. We, therefore, studied the microbiota associated with Sphagnum forming the main vegetation in undomesticated, evolutionary old bog ecosystems. In our complementary analysis of a culture collection, metagenomic data and a fosmid library, we identified a low abundant but highly diverse pool of resistance determinants, which targets an unexpected broad range of antibiotics including natural and synthetic compounds. This derives both, from the extraordinarily high abundance of efflux pumps (80%), and the unexpectedly versatile set of ARGs underlying all major resistance mechanisms. The overall target spectrum of detected resistance determinants spans 21 antibiotic classes, whereby {beta}-lactamases and vancomycin resistance appeared as the predominant resistances in all screenings. Multi-resistance was frequently observed among bacterial isolates, e.g. in Serratia, Pandorea, Paraburkhotderia and Rouxiella. In a search for novel ARGs we identified the new class A {beta}-lactamase Mm3. The native Sphagnum resistome comprising a highly diversified and partially novel set of ARGs contributes to the bog ecosystems plasticity. Our results shed light onto the antibiotic resistance background of non-agricultural plants and highlight the ecological link between natural and clinically relevant resistomes.

microbiology↗