Isoform-specific subcellular localization of Zea mays lipoxygenases and oxo-phytodienoate reductase 2

Abstract

Plant 9- and 13-lipoxygenases (9- and 13-LOXs) function in an early step of the oxylipin biosynthesis pathway. Here we report diverse subcellular localization profiles of four maize LOX family proteins and one oxo-phytodienoate reductase 2, subcellular localization of which could not be predicted by bioinformatics tools. Fluorescent protein-tagged LOX proteins were transiently expressed in maize B73 protoplasts as well as in stably transformed Arabidopsis thaliana. Localization profiles of maize 9-LOXs were more diverse than that of reported 13-LOX isoforms and spanned cytoplasm, plastids and tonoplasts, suggesting compartmentation of different oxylipin production inside of the cells. Localization profiles of maize 9-LOX were mostly consistent between maize and Arabidopsis, suggesting subcellular targeting mechanisms of these isoforms are conserved between monocots and dicots.