Email: wolfram.weckwerth@univie.ac.at

All plant roots secrete various metabolites into the root-soil system making up to 40% of their photosynthetic productivity [1]. These enormously complex root exudates have various functions for nutrient acquisition, and most obviously plant – soil microbiome interactions. Plants control the soil microbiome with these root exudates adjusting the species composition of the rhizosphere microbiota involved in nutrient transformations, decomposition and mineralization of organic substances which eventually determines soil quality.

One remarkable process is the secretion of metabolites from the root system which are able to inhibit nitrification processes of bacteria and archaea called biological nitrification inhibition [1]. In effect BNI can lead to less nitrate loss from the soil, especially in conjunction with nitrogen fertilization, and eventually improve nitrogen use efficiency (NUE) of the plant [1]. We are investigating these processes in various cereals such as millets and wheat. Intriguingly, BNI activity is also depending on drought-stress conditions, offering a potential route to improve NUE and drought resistance [2].

Recently, we have introduced the concept of Panomics applied to large germplasm collections [3]. Panomics applies integrative analysis of metabolomics, proteomics, RNAseq, metabolic modelling, AI, machine learning and genomic prediction to natural genetic variation of large crop germplasm collections [3]. The aim is to provide intimate molecular information for breeding programs addressing resilient and sustainable agricultural production systems [1, 2].

Using this platform we investigated various wheat genotypes with respect to their root exudate metabolomes and corresponding effects on the soil microbiota, as well as nitrifiers and BNI activity.

[1] Ghatak, A., et al. (2023) PANOMICS at the interface of root-soil microbiome and BNI. Trends Plant Sci 28, 106-122

[2] Ghatak, A. et al. (2022) Root exudation of contrasting drought-stressed pearl millet genotypes conveys varying biological nitrification inhibition (BNI) activity. Biol Fertil Soils 58, 291-306,

[3] Weckwerth W et al (2020) PANOMICS meets germplasm. Plant Biotechnol J 18: 1507-1525