Stromuling when stressed!

Stromules are stroma-filled tubules, extruding from the plastid and surrounded by both envelope membranes, but so far, stromules remain enigmatic structures and their function unknown. Stromules can interconnect plastids and have been found to associate with the nucleus, endoplasmic reticulum, Golgi complex, plasma membrane, mitochondria and peroxisomes. This minireview briefly summarizes markers to visualize stromules, inducers of stromules and provides new data about plant virus induced stromules.