FIG. 5.

Relative SPI1 mRNA/ACT1 mRNA ratios for the wild type (WT) and Δmsn2 and Δmsn4 mutants 1 h following yeast cell population exposure to 2,4-D (0.3 mM, pH 3.5). Relative SPI1 mRNA/ACT1 mRNA ratios (A) were obtained by densitometry of the autoradiograms (B) and are average values from three experiments. The relative mRNA ratio for the wild type immediately before exposure to the herbicide (control [c]) was set as 1. (C) Corresponding growth curves for the wild-type BY4741 strain (•) and Δspi1 (○), Δmsn2 (▵), and Δmsn4 (□) deletion mutants. Arrows, cell samples harvested for Northern blot assays.