Developing a platform for production of the oxylipin KODA in plants

Abstract

KODA (9-hydroxy-10-oxo-12(Z),15(Z)-octadecadienoic acid) is a plant oxylipin involved in recovery from stress. As an agrichemical, KODA helps maintain crop production under various environmental stresses. In plants, KODA is synthesized from α-linolenic acids via 9-lipoxygenase (9-LOX) and allene oxide synthase (AOS), although the amount is usually low except in the free-floating aquatic plant Lemna paucicostata. To improve KODA biosynthetic yield in other plants such as Nicotiana benthamiana and Arabidopsis thaliana, we developed a system to overproduce KODA in vivo via ectopic expression of L. paucicostata 9-LOX and AOS. The transient expression in N. benthamiana showed that the expression of these two genes is sufficient to produce KODA in leaves. However, stable expression of 9-LOX and AOS (with consequent KODA production) in Arabidopsis plants succeeded only when the two proteins were localized in plastids or the endoplasmic reticulum/lipid droplets. Although only small amounts of KODA could be detected in leaf extracts of transgenic Nicotiana or Arabidopsis plants, subsequent incubation of the extracts increased KODA abundance over time. Therefore, KODA production in transgenic plants stably expressing 9-LOX and AOS requires specific subcellular localization of these two enzymes and incubation of leaf crude extracts, which liberates α-linolenic acid via breakdown of endogenous lipids.

Mass Spectrometry-Based Targeted Lipidomics and Supervised Machine Learning Algorithms in Detecting Disease, Cultivar, and Treatment Biomarkers in Xylella fastidiosa subsp. pauca-Infected Olive Trees

“…The oxylipins that increase during infection (Table 2) could affect Xylella lifestyle (i.e., promoter of biofilm), have antibacterial activity (Mundt et al, 2003), and promote oxidative stress (9,10-di HOME; Gabbs et al, 2015). The oxylipins that decrease in the infected samples (e.g., 9-oxoODE and 9-oxoOTrE) are plant growth promoters and enhancers of resistance to multiple stresses (Ihara et al, 2021; Table 2 and Figure 3).…”