The Quantification of Jasmonates in Lipid-Rich Tissues by UHPLC-ESI-QQQ-MS/MS in Multiple Reaction Monitoring (MRM)

Jasmonates are a group of plant signaling compounds that control defense mechanisms and modulate growth and development in response to environmental challenges. The protocol in this chapter describes a simple and rapid quantification of the most commonly studied jasmonate, jasmonic acid (JA), and also both its precursor 12-oxo-phytodienoic acid (OPDA) and JA-isoleucine (JA-Ile) the bioactive form, in the abscission zone (AZ) and the mesocarp tissue of oil palm fruits. These tissues are lipid-rich and difficult to analyze because of high levels of triglycerides (TAGs). When TAGs are extracted by apolar solvents, the column and analytical system can be clogged, and the jasmonate quantification is perturbed. In order to determine jasmonate distribution in lipid-rich tissues, we present a protocol to eliminate TAGs to successfully extract and quantify jasmonates, including 12-oxo-phytodienoic acid (OPDA), the most apolar compound, and JA-Ile, the form that binds to the JA co-receptor complex and regulates responses through JA signaling. The protocol is used with the objective of understanding the function of jasmonates in the AZ of ripe oil palm fruit during abscission.