2.7.2.8 additional information threefold repression of enzyme formation by arginine 725629 2.7.2.8 up the enzyme expression is significantly induced by PEG 6000 (10% (w/v)), NaCl (100 mM), abscisic acid (0.1 mM), brassinosteroid (50 nM) and H2O2 (10 mM) 761182