Subcellular Localization and Characterization of Zea mays 9-Lipoxygenase Isoforms
Abstract
Lipoxygenases are often rate limiting enzymes in plant oxylipin biosynthesis pathway. While 13-lipoxygenases have been extensively investigated in plants, characterization of plant 9-lipoxygenases are still in its infancy. Through subcellular localization, biochemical, and genetic analysis, this study characterizes the localization of many of the Zea mays 9-lipoxygenases and related lipid metabolism enzymes. This work also includes a more in-depth analysis of Zea mays LOX6 using Arabidopsis transgenic plants overexpressing ZmLOX6.
Analysis of Zea mays 9-LOX genes tagged with GFP fusion proteins is the initial step in understanding the in vivo functionality of 9-lipoxygenases. I found that ZmLOX1 and OPR2 localized to the cytosol. Unexpectedly, ZmLOX4, and ZmLOX5 had shown both cytosolic and tonoplast localization. ZmLOX12 localized to an undetermined organelle cell structure.
ZmLOX6 is an unconventional LOX-like protein in maize and is localized to plastid. When overexpressed in Arabidopsis, ZmLOX6 produced a range of C5 volatiles and caused a variety of phenotypic such as chlorosis, early flowering in the Arabidopsis host plants. ZmLOX6 overexpressing plants (ZmLOX6-OX) induces chlorosis to wild type plants in close proximity, suggesting C5 volatiles produced via ZmLOX6 are the cause of the chlorosis. The ZmLOX6-OX lines appear to attract aphids indicating C5 volatiles function in plant-insect interaction.
Citation
Tolley, Jordan Peter (2020). Subcellular Localization and Characterization of Zea mays 9-Lipoxygenase Isoforms. Master's thesis, Texas A&M University. Available electronically from https : / /hdl .handle .net /1969 .1 /191892.