Methyltransferase involved in the biosynthesis of methyl anthranilate in response to stresses. Utilizes anthranilic acid as substrate, but not salicylic acid. Produces exclusively the O-methyl ester. anthranilate + S-adenosyl-L-methionine = O-methyl anthranilate + S-adenosyl-L-homocysteine kcat is 0.45 sec(-1) with anthranilic acid as substrate. kcat is 0.04 sec(-1) with benzoic acid as substrate. Up-regulated by herbivory and jasmonic acid, but not by salicylic acid. Because cv. Delprim is a hybrid line, AAMT1 and AAMT1I are likely alleles of one single locus. However, AAMT1I showed no enzymatic activity with all tested substrates (PubMed:20519632). Belongs to the methyltransferase superfamily. Type-7 methyltransferase family. SABATH subfamily.