Table 2.
Effect of PHN on energy metabolism after 24 h of treatment
| Control | Phenantrene | Rank sum test | |
|---|---|---|---|
| (DMSO) | 200 μM | ||
| Chlorophyll (mg.g-1 FW) | 0.45 ± 0.09 | 0.73 ± 0.11 | P = 0.004 |
| Respiration with respect to chlorophyll content (nmolO2.h−1.mg−1 chlorophyll−1) | 19.62 ± 2.52 | 16.11 ± 2.65 | ns (P = 0.065) |
| Respiration with respect to fresh weight (nmolO2.h−1.mg FW−1) | 8.74 ± 1.33 | 11.72 ± 2.72 | P = 0.041 |
| Cyanide-resistant respiration (%) | 46.86 ± 5.07 | 48.70 ± 7.6 | ns (P = 0.485) |
| Photosynthesis with respect to chlorophyll content (nmolO2.h−1.mg−1 chlorophyll−1) | 79.11 ± 5.96 | 40.56 ± 6.62 | P = 0.004 |
| Photosynthesis with respect to fresh weight (nmolO2.h−1.mg FW−1) | 35.93 ± 6.31 | 29.46 ± 6.46 | ns (P = 0.082) |
| Photosynthesis/respiration ratio | 4.10 ± 0.34 | 2.54 ± 0.35 | P = 0.004 |
Four-week-old plants grown in vitro in MS/2 medium were treated for 24 h with 200 μM PHN before measurements of leaf chlorophyll content, respiration and photosynthesis. Data are indicated as average with SD (n = 5 or 6), and due to the small sample size, a non-parametric Mann–Whitney rank sum test was applied (ns non significant)