Represses or inhibits nitriles production from methionine-derived and from indol-3-ylmethyl glucosinolates. Favors isothiocyanate production. In cv. Columbia, altered ratio of endogenous nitrile to isothiocyanate hydrolysis products. ESM1 is highly expressed in cv. Columbia while lowly expressed in cv. Landsberg erecta. Belongs to the 'GDSL' lipolytic enzyme family.