FIG. 2.

P. ostreatus mnp gene expression, 2 h after addition of Mn²⁺ (23 ppm in 1% Tween 20) to a 7-day-old culture grown on cotton stalks. Gene expression was determined using relative RT-PCR and specific primer sets for each gene as explained in the Fig. 1 legend. Since the same pattern of linear range was observed, only one RNA concentration is presented. β-Tubulin gene expression was used as an internal control. (A) Nonamended control; (B) 1% Tween 20 control; (C) Mn²⁺ amendment (23 ppm).