However, L-trp results in neither repression nor derepression in the mutant, but it can counteract the activity of CXM or IPA.

• 对CXM抗性变株,CXM与IPA均表现为去阻遏作用,L-trp不具阻遏作用,但可抵消CXM和IPA的去阻遏作用。