Dissertation

The early stress response of jasmonic acid in cell suspension cultures of Catharanthus roseus

Author: Goldhaber Pasillas, G.D.
Date: 16 December 2020
Links: Thesis in Leiden Repository

In order to gain a better insight into the basis of the rapid jasmonic acid (JA)-mediated stress response, an integrated approach using a targeted high-resolution mass spectrometry-based (HRMS) platform, was conducted to monitor the metabolism of JA using the model system of cell suspension cultures of Catharanthus roseus. Components in the JA-pathway involved in the primary metabolism such as the fatty acid (FA)-precursor C18:3; terpenoid indole alkaloids (TIA) belonging to the secondary metabolism and JA derivatives involved in its catabolism were examined. The effects of JA on FA and TIA in cell suspension cultures of C. roseus were time dependent and are thus considered late events in the JA-stress response. Feeding cells with d5-dnOPDA led to the accumulation of d5-JA and d5-JA-Ile in cells, proving that cells are constitutively ready to incorporate and transform dnOPDA into JA-Ile catalyzed by JA-amino synthetase 1 (JAR1). Moreover, d5-JA was excreted to the growth medium possibly by JA/JA-Ile TRANSPORTER 1 (JAT1). Signal attenuation of JA included the accumulation in cells of 12-hydroxyjasmonic acid (12-HOJA), 12-hydroxyjasmonoyl-L-isoleucine (12-HOJA-Ile) and 12-carboxyjasmonoyl-L-isoleucine (12-HOOCJA-Ile) and 12-O-glucosyl-jasmonic acid (12-O-Glc-JA), as well as 9,10-dihydrojasmonic acid (DHJA) in growth medium.