LexA-TaSTOP1-A exhibits transactivation potential in yeast. EGY48 cells co-expressing the lexA-TaSTOP1-A and a report cassette bearing the lacZ gene driven by a promoter containing lexA binding sites were grown in selective medium in the presence or absence of Al. Qualitative overlay-assay performed on solid medium (A) and quantitative measurements of β-galactosidase activity normalized to the A600 of cells (B). Values are means (± SD) of six independent transformants. Asterisks denote significant differences as identified by paired t-tests (**: P < 0.001).