The regulatory gene nit-2 of Neurospora crassa complements a nnu mutant of Gibberella zeae (Fusarium graminearum).

The nnu mutant of Gibberella zeae (=Fusarium graminearum) is unable to catabolize many of the nitrogen sources utilized by its wild-type parent, and may have suffered a mutation in the major nitrogen regulatory locus. Transformation of this mutant with the major nitrogen regulatory gene from Neurospora crassa, nit-2, restored the wild-type phenotype, thus confirming that the nnu mutation is in the major nitrogen regulatory locus of G. zeae. Our results are consistent with the premise of conservation of the structure of regulatory factors and suggest the possibility that functional DNA homologues of this regulatory element occur across a broad range of ascomycetous fungi.