JELÍNKOVÁ, Adriana, MALÍNSKÁ, Kateřina, SIMON, Sibu, KLEINE-VEHN, J., PAŘEZOVÁ, Markéta, PEJCHAR, Přemysl, KUBEŠ, Martin, MARTINEC, Jan, FRIML, J., ZAŽÍMALOVÁ, Eva, PETRÁŠEK, Jan. Probing plant membranes with FM dyes: tracking, dragging or blocking? Plant Journal. 2010, 61(5), 883-892. ISSN 0960-7412. E-ISSN 1365-313X

Remarkable progress in various techniques of in vivo fluorescence microscopy has brought an urgent need for reliable markers for tracking cellular structures and processes. The goal of this manuscript is to describe unexplored effects of the FM (Fei Mao) styryl dyes, which are widely used probes that label processes of endocytosis and vesicle trafficking in eukaryotic cells. Although there are few reports on the effect of styryl dyes on membrane fluidity and the activity of mammalian receptors, FM dyes have been considered as reliable tools for tracking of plant endocytosis. Using plasma membrane-localized transporters for the plant hormone auxin in tobacco BY-2 and Arabidopsis thaliana cell suspensions, we show that routinely used concentrations of FM 4-64 and FM 5-95 trigger transient re-localization of these proteins, and FM 1-43 affects their activity. The active process of re-localization is blocked neither by inhibitors of endocytosis nor by cytoskeletal drugs.