Labeling of major plant lipids and jasmonic acid using [1- ¹⁴C] lauric acid

A medium chain length fatty acid, [1- ¹⁴C] lauric acid (12:0) was administered to the detached leaves of Artemisia and was incorporated into major lipids, including phospholipids and galactolipids. [1- ¹⁴C]12:0 was elongated and desaturated into linolenic acid (18:3). In detached leaves of both Artemisia and Arabidopsis thaliana ecotype Columbia, radioactivity from [ ¹⁴C]18:3 was incorporated into jasmonic acid (JA) and methyl jasmonate (MJ). Higher amounts of [ ¹⁴C]JA were measured in Artemisia than Arabidopsis leaves. In Artemisia, [ ¹⁴C]JA was actively metabolized into [ ¹⁴C]MJ. Extracts prepared from the leaves of Artemisia, exhibited higher in vitro JA methyltransferase activity than those from Arabidopsis.