caa a22 4500 606217681 CHVBK 20210128101109.0 cr unu---uuuuu 210128e20150701xx s 000 0 eng 10.1007/s11104-015-2412-x doi (NATIONALLICENCE)springer-10.1007/s11104-015-2412-x Root expression of nitrogen metabolism genes reflects soil nitrogen cycling in an organic agroecosystem [Elektronische Daten] [Timothy Bowles, Philipp Raab, Louise Jackson] Background and aims: Roots in agroecosystems encounter spatially and temporally heterogeneous nitrogen (N) availability in soil. Understanding root physiological processes in concert with soil microbial N dynamics following spatially discrete N pulses under field conditions will aid in the management of agroecosystem processes for N use efficiency. Methods: This study examined the short-term response (<5days) of tomato (Solanum lycopersicum L.) roots and soil N cycling to a pulse of inorganic N in an undisturbed soil patch on an organic farm using a novel combination of molecular and 15N isotopic techniques. Results: Tomato roots rapidly responded to and exploited the N pulse via upregulation of key N metabolism genes (e.g. cytosolic glutamine synthetase GS1) that comprise the core physiological response of roots to patchy soil N availability. Strong root activity limited accumulation of soil NO3 − despite high rates of gross nitrification. Roots out-competed soil microbes for the inorganic N, even on a short time scale, likely as a result of high plant N demand and microbial C limitation. The transient root gene expression response (absent by 4days after the N pulse) underscored the sensitivity of root N uptake to local N availability. Conclusions: Root expression of genes such as GS1 could complement soil inorganic N pools and measurements of soil microbial activity to serve as integrative indicators of rapid plant-soil N cycling. Springer International Publishing Switzerland, 2015 Root gene expression nationallicence Cytosolic glutamine synthetase nationallicence Isotope pool dilution nationallicence Tomato ( Solanum lycopersicum ) nationallicence Nitrogen cycling nationallicence Bowles Timothy Department of Land, Air and Water Resources, University of California Davis, 95616, Davis, CA, USA aut Raab Philipp Department of Land, Air and Water Resources, University of California Davis, 95616, Davis, CA, USA aut Jackson Louise Department of Land, Air and Water Resources, University of California Davis, 95616, Davis, CA, USA aut Plant and Soil Springer International Publishing 392/1-2(2015-07-01), 175-189 0032-079X 392:1-2<175 2015 392 11104 https://doi.org/10.1007/s11104-015-2412-x text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s11104-015-2412-x text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Bowles Timothy Department of Land, Air and Water Resources, University of California Davis, 95616, Davis, CA, USA aut NATIONALLICENCE 700 1- Raab Philipp Department of Land, Air and Water Resources, University of California Davis, 95616, Davis, CA, USA aut NATIONALLICENCE 700 1- Jackson Louise Department of Land, Air and Water Resources, University of California Davis, 95616, Davis, CA, USA aut NATIONALLICENCE 773 0- Plant and Soil Springer International Publishing 392/1-2(2015-07-01), 175-189 0032-079X 392:1-2<175 2015 392 11104