Targeted Quantitative Analysis of Jasmonic Acid (JA) and Its Amino Acid Conjugates in Plant Using HPLC-Electrospray Ionization-Tandem Mass Spectrometry (ESI-LC-MS/MS)

Abstract

Jasmonic acid (JA) and its amino acid conjugates are critical signaling components involved in various aspects of plant growth, development and defense. Their constitutive and induced (due to a variety of environmental factors) levels vary from plant to plant and also from tissue to tissue within the same plant. To better understand the JA-mediated signaling and metabolic pathways, abso-lute quantification of JA and its conjugate(s) is essential in plants/tissues/organs during development and abiotic/biotic stresses. Here, we present an experimental protocol for extraction of JA and conjugates as well for absolute quantification applicable to both monocotyledonous (such as rice, maize) and dicotyledonous (such as Arabidopsis, Ox Knee) plants using high-pressure liquid chromatography-electrospray ionization-tandem mass spectrometry, which is still technically chal-lenging. Our decade of experience has been blended in this protocol. In this chapter, we provide examples of a dicot plant and the absolute quantification of JA and JA-isoleucine in leaves.