Table 1.
Alternative respiratory pathway capacity in transgenic plant lines expressing AOX or AOX-E that were used in this study
| Oxygen Consumption Rates (nmol O2 min-1/106 cell)2 | |||||||
|---|---|---|---|---|---|---|---|
| Plant Line1 | Transgene(s) | Control | Antimycin A | Antimycin A + SHAM | Corrected Control3 | AP Capacity4 | n |
| NT | - | 1.86 ± 0.08 | 1.43 ± 0.01 | 0.04 ± 0.04 | 1.82 | 1.39 | 8 |
| AOX1 | 35S:Aox1a | 5.35 ± 0.36 | 6.08 ± 0.68 | 0.79 ± 0.13 | 4.57 | 5.30 | 3 |
| AOX3 | 35S:Aox1a | 3.38 ± 0.33 | 4.62 ± 0.54 | 0.54 ± 0.11 | 2.83 | 4.07 | 3 |
| AOX-E3 | 35S:Aox-E | 2.03 ± 0.28 | 0.77 ± 0.13 | 0.39 ± 0.06 | 1.64 | 0.39 | 4 |
| AOX-E5 | 35S:Aox-E | 1.68 ± 0.11 | 0.73 ± 0.11 | 0.18 ± 0.02 | 1.50 | 0.55 | 3 |
| Empty vector control | - | 2.18 ± 0.27 | 1.34 ± 0.11 | 0.29 ± 0.03 | 1.89 | 1.05 | 4 |
| RD/AOX2 | 35S:Aox1a/ 35S:MtRDR1 | 1.99 ± 0.06 | 2.47 ± 0.13 | 0.065 ± 0.003 | 1.93 | 2.41 | 3 |
| RD/AOX22 | 35S:Aox1a/ 35S:MtRDR1 | 2.08 ± 0.03 | 2.55 ± 0.01 | 0.105 ± 0.024 | 1.98 | 2.45 | 3 |
Notes.
1Leaf cells isolated from non-transgenic (NT) Nicotiana benthamiana plants, transgenic plants expressing Aox1a or Aox-E sequences under the control of the cauliflower mosaic virus 35S promoter, plants harboring a 35S:MtRDR1 transgene super-transformed with the 35S:Aox1a transgene, or from plants transformed with an 'empty' transformation vector were placed in an oxygen electrode. The number (n) of independent oxygen electrode experiments (each of which comprised three technical replicates) carried out for each plant line is indicated.
2Oxygen consumption rates (± standard error of the mean) were measured in the absence (Control) or presence of 25 μM antimycin A (an inhibitor of the cytochrome pathway) or 25 μM antimycin A plus 2 mM salicylhydroxamic acid (SHAM: an inhibitor of the alternative respiratory pathway). Rates determined when both inhibitors were present, gave a measure of residual, i.e. non-respiratory, oxygen consumption.
3Last two columns: residual values were used to derive corrected values for the control oxygen consumption rates, and oxygen consumption rates in the presence of antimycin A, which gives the alternative respiratory pathway (AP) capacity for each line.
4AP capacity in plant cells expressing the Aox or Aox-E transgenes were significantly different from that observed in cells from non-transgenic plants (p<0.05: Student's t-test).