Table I.

Activity and nucleotide content in amk mutants

Rosette leaves of seedlings were analyzed after 21 d of growth on plates containing one-half-strength MS with 0.5% Suc. Activity data are given as percentage of the controls, with forward reaction at 4.2 ± 1.3 nmol s−1 (mg protein)−1 and backward reaction at 4.0 ± 1.5 nmol s−1 (mg protein)−1. Each data point represents the mean and sd of seven replicates for amk2, nine replicates for congenic wild-type and heterozygous plants, and four replicates for amk5. Significant differences (P < 0.1) using unpaired two-tailed t tests are marked with an asterisk.

amk2AMKamk5
Activity
    Forward reaction (% of control)79 ± 15.7*100 ± 19.299 ± 7.3
    Backward reaction (% of control)63 ± 14.9*100 ± 4.3101 ± 15.5
Metabolite content
    AMP (nmol g FW−1)3.9 ± 1.85.4 ± 2.47.5 ± 1.0
    ADP (nmol g FW−1)8.5 ± 4.5*25.5 ± 8.831.6 ± 2.0
    ATP (nmol g FW−1)18.7 ± 7.4*50.4 ± 19.458.0 ± 10.1
    Purine (nmol g FW−1)32.8 ± 8.4*89.5 ± 26.2110 ± 15.9
    Adenylate energy charge ([ATP] + [0.5 × ADP]) × ([ATP] + [ADP] + [AMP])−10.72 ± 0.09*0.79 ± 0.050.77 ± 0.03