Table I.

Number and type of the selected mutants

Activity of the Ars gene under control of the Nia1 promoter is shown in the pNia1-Ars lines where +, −, and ++ represent presence, absence, and overexpression of activity in the appropriate screening media, respectively. Growth (+) or no growth (−) on nitrate media of the same strains is indicated in the Nit lines. AI, Ammonium insensitive mutants; NI, nitrate insensitive mutants; ON, overexpressed in nitrate mutants. –, No mutant of this type.

Phenotype for ARS Activity and NitNumber of Isolated Mutants
AINION
pNia1-Ars+40
pNia1-Ars47
pNia1-Ars++58
Nit713
Nit+404045
Total145