Visualisation of stromules on Arabidopsis plastids.

Stromules are thin stroma-filled tubules that extend from all plastid types in all multicellular plants examined. They are most easily visualised by epifluorescence or confocal microscopy of plastids containing green fluorescent protein (GFP) or other fluorescent proteins. Transient expression of gene constructs encoding plastid-targeted GFP following bombardment of whole plants or organs of Arabidopsis with gold or tungsten particles coated with plasmid DNA is a relatively rapid and simple means of producing material for observation of stromules.