Figure 5. The HpDTC1 promoter is regulated by abiotic and biotic stress responses in the moss Physcomitrella patens.

(a) HpDTC1 promoter::GUS (HpDTC1::GUS) expression was histochemically visualized after 24 h stress treatment. The HpDTC1::GUS reporter was highly induced by CuCl₂ (500 μM), chitosan (250 μg/ml), and chitosan oligomers (Average Mw = 4000–6000, 250 μg/ml), but not by jasmonate, JA, (100 μM) on leafy gametophores (upper panel). The vector control line did not respond to the stress treatments (lower panel). Scale bars: 1 mm. The quantitative data for HpDTC1::GUS reporter induction at 24 h treatment (b) by CuCl₂ (500 μM), chitosan (250 μg/ml), chitosan oligomers (250 μg/ml), and JA (100 μM), and at the indicated time (c) by CuCl₂ (500 μM) and chitosan (250 μg/ml). The GUS activity of HpDTC1::GUS gametophores was fluorometrically determined. Data are presented as mean ± standard deviation of biological replicates (n = 5 for (b), n = 4 for (c); *p < 0.001).