000K utf8 1100 $c2024 1500 eng 2050 urn:nbn:de:gbv:8:3-2024-01143-8 3000 Dölger, Jasper Lauritz 4000 Potassium/magnesium antagonism$dan investigation of its characteristics during uptake, translocation, and physiological functions$hChristian-Albrechts-Universität zu Kiel [Dölger, Jasper Lauritz] 4030 Kiel$nChristian-Albrechts-Universität zu Kiel 4209 The primary cause of the global occurrence of Mg deficiency is the wide potassium (K)/magnesium (Mg) ratios in the soil solution. High K concentrations have been demonstrated to suppress the uptake of Mg. In addition, mounting evidence indicated that K can suppress the translocation and physiological functions of Mg in plants. The current models and working hypotheses do not account for all findings and contradictions regarding this nutrient interaction. Therefore, this thesis aims to investigate the characterization of the exact pattern of K/Mg interaction and evaluate foliar fertilization as an alternative application form under antagonistic conditions. According to the current model, high concentrations of K suppress the uptake of Mg, as both cations are absorbed through non-selective cation channels. The results of this study on oat and maize demonstrated that the suppressive effect of K on Mg uptake is limited. The suppressive effect diminishes with the further increase of the K/Mg ratio. These findings are supported by investigated Mg-specific uptake transporter ZmMGT10, which exhibited higher relative mRNA expression levels in response to elevated K exposure in maize plants. Despite the long-standing recognition of ZmMGT10 as a selective Mg uptake transporter under conditions of deficiency, its role in the K/Mg interaction remained unexplored prior to this study. Furthermore, this thesis on maize and oat demonstrates that elevated levels of K in the root have a synergistic rather than antagonistic effect on Mg translocation, contrary to the previous assumption by the scientific consensus. These findings are additionally supported by the investigation of a Mg-specific translocation transporter (MGR6). Under high K concentrations, this transporter exhibited higher expression levels. Due to the long-term increase in Mg translocation under such high K conditions, it can be inferred that a greater quantity of Mg is translocated via MGR6. 4950 https://nbn-resolving.org/urn:nbn:de:gbv:8:3-2024-01143-8$xR$3Volltext$534 4961 https://macau.uni-kiel.de/receive/macau_mods_00005445 5051 630 5550 antagonism 5550 foliar fertilization 5550 magnesium deficiency 5550 potassium 5550 transporter