Nitrogen-cycling plant microbiomes and their influence on crop nutrition

Nitrogen (N) is crucial for forming proteins, nucleic acids, and chlorophyll, essential for photosynthesis. Its availability in soil directly impacts plant metabolism, influencing growth and productivity. In agriculture, N limitation is countered with applying synthetic fertilizers, yet their excessive use poses risks like eutrophication and contributing to climate change, necessitating reduced global inputs.
Microorganisms are key players in the global N cycle. However, the role of the plant microbiome in N nutrition remains poorly understood. This project aims to investigate how plant-associated bacteria influence N cycling and enhance its uptake into plants. For this, we chose wheat as model plant, a significant crop in Austria. Wheat plants were cultivated in sterilized soil and inoculated with soil microbiomes in a controlled greenhouse setting. To avoid any abiotic factors influencing plant growth, microbial cells were extracted from diverse donor soils.
For this, several extraction methods were tested. Under N limitation, extracted microbiomes enhancing N uptake will be identified through phenotypic analysis combined with microbial community analyses. Microbiomes showing most and least beneficial effects on plant N nutrition will be further characterized by assessing N-cycling and plant N transporter genes' abundance and activity, followed by a comprehensive metagenomic analysis to understand microbiome dynamics and functions. Moreover, microorganisms with certain metabolic functions will be selectively isolated and further characterized. Their effectiveness in enhancing N uptake and promoting plant growth will be tested individually and in different consortia compositions.
This interdisciplinary study integrates microbiology, plant physiology, and bioinformatics to enhance wheat N nutrition and promote sustainable agricultural practices. Our research aims to mitigate emerging threats to human and planetary health from the overuse of industrial N fertilizers by harnessing beneficial effects of specific players within soil microbiomes