Characterization of a new class of blue-fluorescent lipid droplet markers for live-cell imaging in plants.

KEY MESSAGE: The present work demonstrates the use and advantages of novel, live cell permeable, lipid droplet localizing, non toxic, blue fluorochromes for use in live plant cells. Lipid droplets (LDs) are ubiquitous components of both animal and plant cells. They consist of a core of neutral lipids surrounded by a monolayer of phospholipids, glycolipids and/or sterols with embedded amphipathic proteins. Although initially considered to be simple energy depots, they have recently emerged as organelles that serve important regulatory functions. Here we report three new fluorochromes as markers for LDs in plants. These bright blue fluorochromes with their unique spectral properties can easily be combined with other green and red fluorescent reporters for multicolor fluorescence imaging. The fluorochromes are non-toxic and photo-stable. All in all, they represent a reliable tool to use, for the investigation of dynamic LD biology within living plant cells using fluorescence microscopy.