Forisomes as calcium-energized protein complex: a historical perspective

Forisomes are spindle-shaped (about 1-3 µm wide and 10-30 µm long) contractile moving protein bodies found exclusively in phloem sieve tubes of Fabaceae (legume) plants. They are composed of ATP-independent, mechanically active proteins with several subunits called "forisomettes" and play important role in plant defence against injury. They expand and contract reversibly independent of ATP in response to changes of concentration of Ca2+ ions and pH or electric field. Although forisomes have been discovered decades ago, but only recently they received broader attention due to their ability to convert chemical into mechanical energy. Forisomes have possible applications as biomimetic smart materials (e.g. valves in microdevices), or smart composite materials for nanotechnological applications. Forisome-based smart materials can be used to synthesize self-powered monitoring and diagnostic systems for health monitoring. Here we discuss precise overview of forisomes from a historical viewpoint. We also enlist the scientific events leading to the identification and characterization of forisomes and their potential applications. The advancements in forisomes research have marked the evolution of new trends in the field of applied 'biomimetics' (means: to 'mimic life').