Figure 5.
Respiration activities in wild-type and mutant lines. O2-uptake rates of wild-type plants and nmat2, pmh2 and nmat2/pmh2 mutants were analyzed with a Clark-type electrode as we described previously [35]. For each assay, equal weight (i.e., 100 μg) three-week-old MS-grown Arabidopsis seedlings were submerged in 2.5–3.0 mL sterilized water and applied to the electrode in a sealed glass chamber in the dark. O2-uptake rates were measured in the absence (Control) or in presence of rotenone (ROT, 50 μM) and potassium cyanide (KCN, 1 mM) which inhibit complexes I and IV activities, respectively. The values are means of four biological replicates (error bars indicate one standard deviation). The asterisk indicates a significant difference from wild-type plants (Student’s t-test, p 0.05).