The aim of this experiment is to analyse the effect of the transfer from 1-g to microgravity on the polarity of statocytes and the role of actin filaments on the positioning of the organelles for Cytochalasin B treated roots as well for control, non-treated, roots. In addition of this morphogenetic investigations, the second part of this experiment addresses the question of whether starch metabolism is affected by microgravity conditions. Previous results strongly suggest that starch metabolism may be modified under microgravity conditions. More data are needed since it is unclear if this measured decrease in starch content is caused by less synthesis (anabolism processes) or by increased degradation (catabolism processes) or both. Experiment Specimens: Lentil (Lens culinaris, cv. "Verte du Puy") seedlings

Lentil seedlings are hydrated either with water alone or with a diluted solution of Cytochalasin B in DMSO, grown at 22degC on one of the onboard 1-g control centrifuge during 30 hours and exposed to microgravity for 5 to 120 minutes. The seedlings are observed and video-recorded before being chemically fixed at the end of the experiment. For the second part of the experiment dry lentil seeds are activated in orbit, by water injection , incubated at 22degC and, between 3 and 6 days after activation, the seedlings are either chemically fixed for microscopic investigations (morphometric analysis of cell organelles size, shape and spatial distribution) or frozen for biochemical analysis including determination of glycosyl transferase, phosphorylase and amylases.