Table I. Relative activity of recombinant and purified maize AAMT enzymes and OMT8 with various substrates.
Values are averages of four independent measurements. All substrates were tested at a 1.5 mm concentration, and methyltransferase activity was determined by measuring the radioactivity of the transferred 14C-methyl group from SAM. The relative activity of the three AAMTs with anthranilic acid was set arbitrarily at 100%. nd, Not determined.
| Substrate | AAMT1 Relative Activity | AAMT2 Relative Activity | AAMT3 Relative Activity | OMT8 Relative Activity |
| % | ||||
| Anthranilic acid | 100 | 100 | 100 | 0 |
| Benzoic acid | 3 | 3 | 26 | 100 |
| Salicylic acid | 0 | 0 | 2 | 0 |
| Indole-3-acetic acid | 0 | 0 | 2 | nd |
| Jasmonic acid | 0 | 0 | 1 | nd |
| Cinnamic acid | 0 | 0 | 0 | 0 |
| Coumaric acid | 0 | 0 | 0 | 0 |