1.8.4.9 (NH4)2SO4 500 mM, stimulates 687585 1.8.4.9 (NH4)2SO4 highly activating 687585 1.8.4.9 Fe2+ APR contains a FeS cluster 694695 1.8.4.9 Fe2+ FeS cluster as a cofactor in PpAPR 687585 1.8.4.9 KNO3 500 mM, stimulates 687585 1.8.4.9 Mg2+ - 694695 1.8.4.9 Mg2+ activates 18-24fold at 500 mM 687585 1.8.4.9 MgCl2 500 mM, stimulates 687585 1.8.4.9 MgSO4 500 mM, stimulates 687585 1.8.4.9 additional information no iron is associated with recombinant PpPAPR 687585 1.8.4.9 NaCl all three APR isoforms increased 3fold in roots after 5 h of treatment with 150 mM NaCl, regulation of salt stress by plant hormone signalling, overview 694712