Figure 5. Effects of sulfite on catalase activity and gene expression in wild-type and ZmSO over-expression tobacco plants.

(A) Effect of sulfite on total catalase (CAT) activity in wild-type and OE lines (OE-3 and OE-7). Leaf samples from wild-type and OE plants were harvested after 16 h of 5 mM Na₂SO₃ treatment and total CAT activities were analyzed. Values are means ± SE (n = 6). Means denoted by the same letter did not significantly differ at P<0.05. (B) Effect of sulfite on transcription levels of Cat1 in wild-type and OE lines (OE-3 and OE-7). (C) Effect of sulfite on transcription levels of Cat2 in wild-type and OE lines (OE-3 and OE-7). In both assays, leaf samples from wild-type and OE plants were harvested after 16 h of 5 mM Na₂SO₃ treatment and transcriptional expression of Cat1 and Cat2 was detected by qRT-PCR.