TY - JOUR AU - Kuang, Weiqi AU - Sanow, Stefan AU - Kelm, Jana M AU - Müller Linow, Mark AU - Andeer, Peter AU - Kohlheyer, Dietrich AU - Northen, Trent AU - Vogel, John P AU - Watt, Michelle AU - Arsova, Borjana TI - N-dependent dynamics of root growth and nitrate and ammonium uptake are altered by the bacterium Herbaspirillum seropedicae in the cereal model Brachypodium distachyon JO - The journal of experimental botany VL - 73 IS - 15 SN - 0022-0957 CY - Oxford PB - Oxford Univ. Press M1 - FZJ-2022-02502 SP - 5306–5321 PY - 2022 AB - Nitrogen (N) fixation in cereals by root-associated bacteria is a promising solution for reducing use of chemical N fertilizers in agriculture. However, plant and bacterial responses are unpredictable across environments. We hypothesized that cereal responses to N-fixing bacteria are dynamic, depending on N supply and time. To quantify the dynamics, a gnotobiotic, fabricated ecosystem (EcoFAB) was adapted to analyse N mass balance, to image shoot and root growth, and to measure gene expression of Brachypodium distachyon inoculated with the N-fixing bacterium Herbaspirillum seropedicae. Phenotyping throughput of EcoFAB-N was 25–30 plants h−1 with open software and imaging systems. Herbaspirillum seropedicae inoculation of B. distachyon shifted root and shoot growth, nitrate versus ammonium uptake, and gene expression with time; directions and magnitude depended on N availability. Primary roots were longer and root hairs shorter regardless of N, with stronger changes at low N. At higher N, H. seropedicae provided 11% of the total plant N that came from sources other than the seed or the nutrient solution. The time-resolved phenotypic and molecular data point to distinct modes of action: at 5 mM NH4NO3 the benefit appears through N fixation, while at 0.5 mM NH4NO3 the mechanism appears to be plant physiological, with H. seropedicae promoting uptake of N from the root medium.Future work could fine-tune plant and root-associated microorganisms to growth and nutrient dynamics. LB - PUB:(DE-HGF)16 C6 - 35512445 UR - <Go to ISI:>//WOS:000813473600001 DO - DOI:10.1093/jxb/erac184 UR - https://juser.fz-juelich.de/record/908268 ER -