Table I.

Effect of 3-OMG on respiration, adenine nucleotide contents, ATP/ADP ratio, and AEC in maize root tips

ConditionRespirationATPADPAMPΣ AdNATP/ADPAEC
nmol O2min−1 tip−1 pmol tip−1
Control3.45 ± 0.302,130 ± 382360 ± 6649 ± 262,540 ± 4655.920.91
Starvation0.70 ± 0.101,213 ± 273225 ± 3433 ± 171,471 ± 3245.400.90
3-OMG (100 mm) 0.85 ± 0.151,239 ± 141216 ± 1530 ± 81,485 ± 1645.740.91
3-OMG (100 mm) + Pi (10 mm)0.78 ± 0.151,364 ± 367270 ± 6643 ± 301,677 ± 4635.050.89

Except for control, defined as a 4-h incubation in 200 mmGlc, root tips were incubated for 48 h without carbon substrate or with 100 mm 3-OMG. When not mentioned, Pi concentration was 0.25 mm. AdNs were extracted and analyzed, and the values of Σ AdN and adenylate energy charge (AEC) were calculated as described in “Materials and Methods.” These data represent the mean of at least two (3-OMG and 3-OMG + Pi), four (starvation), and six (control) independent experiments.