Biology subjects

Buegger, F.

Publications and source records attributed to Buegger, F..

5 recordsLinked to original sources

bioRxiv2025

Provenance Legacies Override Species Effects in Shaping Oak Rhizosphere Microbiomes and Metabolomes

As climate change drives more frequent and intense drought-heat extremes, selecting drought-tolerant trees is crucial for future forest resilience. However, the role of tree-microbial associations for this key trait remains largely unclear. In this study, we investigated how geographic origin, species identity, and intrinsic water-use efficiency (iWUE) shape the rhizosphere microbiome and root-rhizosphere metabolome of pedunculate (Quercus robur) and sessile (Q. petraea) oaks. In a six-year common garden experiment, we analyzed trees from both species, each grown from seeds from two distinct geographic origins, the upper Rhine basin (URB) and the north-east German lowlands (NGL), differing in water availability, using 16S and ITS rRNA gene based metabarcoding and untargeted metabolomics. We found a consistent legacy effect of seed origin on the composition of the prokaryotic rhizosphere microbiome and the metabolome, whereas tree species had no significant impact. The bacterial family Pseudonocardiaceae was enriched at trees from the drier origin NGL, while Blastocatellaceae and Micromonosporaceae were positively associated with iWUE across samples. Higher iWUE was furthermore significantly correlated with lower prokaryotic diversity and shifts in {beta}-diversity, thereby linking a drought-adaptive host trait to the assembly of the belowground environment. Ellagic acid, a plant derived polyphenol associated with drought tolerance, was enriched in the drier origin NGL and linked to several prokaryotic taxa in correlation networks. The rhizosphere fungal community, however, was largely unaffected by origin or species. Solely fungal community evenness declined with increasing iWUE. Together, our findings suggest that ecotypic adaptation linked to origin can outweigh the effect of species-level traits in shaping the oak rhizosphere microbiome and metabolome. These findings emphasize that provenance-driven ecotypic adaptation can strongly influence plant-microbe interactions and underscore the need for provenance-aware selection and microbiome-informed assisted migration as strategies to strengthen forest drought resilience under global climate change.

ecology↗

bioRxiv2025

Functional diversity of soil microbial communities increases with ecosystem development

Land abandonment is the single largest process of land-use change in the Global North driving succession and afforestation at continental scales, but assessing its impacts on soil microbial communities remains a challenge. Here, we established a nationwide successional gradient of paired grassland and forest sites to track developments in microbial structure and functioning following land abandonment and gradually changing plant communities. We show that microbes generally respond through threshold dynamics, leading to increasing functional but decreasing taxonomic diversity. Succession also increased the specialization of microbial nutrient (C-N-P) cycling genes while decreasing genetic redundancy, highlighting a putative trade-off between two desirable ecosystem properties: functional diversity and functional redundancy. Increasing fungal functional diversity underpinned higher microbial C-cycling capacity, underscoring the causal link between functional traits and ecosystem processes. Changing litter quality similarly provided a mechanistic link between plant and microbial communities despite otherwise largely decoupled successional developments. Land abandonment is frequently touted as an opportunity to increase biodiversity and carbon storage. Our results show that deeper knowledge about the multifaceted development of soil microbial communities and its links to plant communities during succession may be needed to fully grasp the impacts of global land abandonment processes.

ecology↗

bioRxiv2024

Multiomics plasticity in seed traits of pan-genome wheat cultivars

The molecular basis of cultivar-level variations in polyploid wheat that enables environmental adaptation while maintaining yield and quality in polyploid wheat remains poorly understood. We conducted a detailed phenotypic assessment and multiomics analysis of nine pan-genome polyploid wheat cultivars grown under control and drought conditions. We aimed to investigate the subgenome-level variations, cultivar differences and biochemical mechanisms affecting plant fitness under moderate drought stress. Intrinsic water use efficiency, grain yield, and grain protein content and quality differed among cultivars, supporting the plasticity of drought stress responses. Biased proteome and metabolome abundance changes in response to moderate drought stress during the vegetative stage indicate different strategies for the utilization of homeologous protein isoforms assigned to the A, B, and D subgenomes. Drought effects were detected at the protein level, but significant changes were observed in central carbon pathway metabolites and micronutrient profiles. The subgenomic localization of seed storage proteins highlight differences in nutrient reservoir accumulation and emphasizes the enhanced role of S-rich prolamins in the stress response. Subgenomic variations define cultivar phenotypes by producing molecules that accumulate and enable the underlying trade-offs between environmental adaptation and yield- or quality-related traits. These variations can be used to select crops with increased stress resistance without compromising yield.

plant biology↗

bioRxiv2022

Towards understanding diversity, endemicity and global change vulnerability of soil fungi

Fungi play pivotal roles in ecosystem functioning, but little is known about their global patterns of diversity, endemicity, vulnerability to global change drivers and conservation priority areas. We applied the high-resolution PacBio sequencing technique to identify fungi based on a long DNA marker that revealed a high proportion of hitherto unknown fungal taxa. We used a Global Soil Mycobiome consortium dataset to test relative performance of various sequencing depth standardization methods (calculation of residuals, exclusion of singletons, traditional and SRS rarefaction, use of Shannon index of diversity) to find optimal protocols for statistical analyses. Altogether, we used six global surveys to infer these patterns for soil-inhabiting fungi and their functional groups. We found that residuals of log-transformed richness (including singletons) against log-transformed sequencing depth yields significantly better model estimates compared with most other standardization methods. With respect to global patterns, fungal functional groups differed in the patterns of diversity, endemicity and vulnerability to main global change predictors. Unlike -diversity, endemicity and global-change vulnerability of fungi and most functional groups were greatest in the tropics. Fungi are vulnerable mostly to drought, heat, and land cover change. Fungal conservation areas of highest priority include wetlands and moist tropical ecosystems.

ecology↗

bioRxiv2020

Cyanobacterial NOS expression improves nitrogen use efficiency, nitrogen-deficiency tolerance and yield in Arabidopsis

Developing strategies to improve nitrogen (N) use efficiency (NUE) in plants is a challenge to reduce environmental problems linked to over-fertilization. The nitric oxide synthase (NOS) enzyme from the cyanobacteria Synechococcus PCC 7335 (SyNOS) has been recently identified and characterized. SyNOS catalyzes the conversion of arginine to citrulline and nitric oxide (NO), and then 70% of the produced NO is rapidly oxidized to nitrate by an unusual globin domain in its 5'-terminus. In this study, we assessed whether SyNOS expression in plants affects N metabolism improving NUE and yield. Our results showed that transgenic Arabidopsis plants had higher primary shoot length and shoot branching when grown in N-deficient conditions and higher seed production in N-sufficient and -deficient conditions. Moreover, transgenic plants showed significantly increased NUE in both N conditions. No differences were observed in N uptake for SyNOS lines. However, SyNOS lines presented an increase in N assimilation/remobilization under low N conditions. In addition, SyNOS lines had greater N-deficiency tolerance compared to wt plants. Our results support that SyNOS expression generates a positive effect on N metabolism and seed production in Arabidopsis, and it might be envisaged as a strategy to improve productivity in crops under adverse N environments.

plant biology↗