Methyltransferase involved in the biosynthesis of methyl anthranilate in response to stresses. Utilizes anthranilic acid as substrate. Produces exclusively the O-methyl ester. anthranilate + S-adenosyl-L-methionine = O-methyl anthranilate + S-adenosyl-L-homocysteine kcat is 0.37 sec(-1) with anthranilic acid as substrate. Slightly up-regulated by herbivory and jasmonic acid, but not by salicylic acid. Belongs to the methyltransferase superfamily. Type-7 methyltransferase family. SABATH subfamily.