Abstract - Nitrogen (N) is a primary nutrient that is essential to the survival of all living organisms. Crops are inefficient in their N use, losing 50-70% of applied N, which transforms to reactive nitrogen Nr, to the environment. This results in increased Nr species, such as NH₃ and nitrous oxide (N₂O) in the atmosphere and nitrate (NO₃^–) in terrestrial and aquatic ecosystems, which has significant consequences for climate change and environmental toxicity. In Australia, agriculture is responsible for ~80% of N₂O emissions.

One of the approaches to tackle the problem of unwanted N losses from the plant/soil system is through the use of inhibitors that delay the microbiological conversion of fertiliser N. Our current ARC funded project aims to test the effects of N movement from controlled growth solutions to improve plant on root growth and morphology without/with novel inhibitors compared to the commercial inhibitors using root growth microcosms, called ‘ROOT-TRAPR’.

This proposed project aims to transition into real world scenarios using pots and a range of soil types to achieve three main objectives:

1. Identify beneficial microbes interacting with plant roots and contributing to improved N uptake and how these interactions are impacted by new fertilizer formulations
2. Characterize in detail the rhizosphere biochemistry underlaying beneficial microbe interaction under different N supply conditions (ie with/without novel inhibitors)
3. Test the efficacy of candidate high-performing novel inhibitors on plant growth performance and ultimately yield

Results obtained from this project will provide important knowledge to identify the mechanisms underpinning plant root-soil-microbiome interactions in response to new fertilisers and eventually plant growth and N use efficiency of target crops along with the knowledge on N release of new fertilisers in response to plant signalling molecules for N acquisition.

Biography - Professor Ute Roessner obtained a PhD in Plant Biochemistry from the University of Potsdam and the Max-Planck-Institute for Molecular Plant Physiology, Germany, in 2001. Professor Roessner research interests are to develop and apply metabolomics methods to study plants grown in different conditions. In 2003 she moved to Australia where she established a GC-MS and LC-MS based metabolomics platform as part of the Australian Centre for Plant Functional Genomics. In 2007, Prof Roessner has been involved in the setup and lead of Metabolomics Australia (MA), a federal and state government funded national metabolomics service facility and led the MA node at the University of Melbourne until 2019. Between 2018 and 2022, Professor Roessner held the position as Head of School, School of BioSciences, University of Melbourne. Since 2022, Prof Roessner holds the position as Academic Director, Research Initiatives and Infrastructure at the Australian National University. Prof Roessner is a Lifetime Honorary Fellow of the International Metabolomics Society. Her contributions to pioneering science in Australia have been recognised by the election to the Victorian Honour Roll of Women in 2020 and in 2021 she has been honoured to be appointed as Member of the Order of Australia (General Division) for her contributions to tertiary education, particular the biosciences.