The gravity-induced re-localization of auxin efflux carrier CsPIN1 in cucumber seedlings: spaceflight experiments for immunohistochemical microscopy

Simulated gravity may help to enable proper growth of food crops in space, say Japanese researchers. Cucumbers normally develop a small, specialized protuberance at the transition between the plant’s root and stem, with gravity acting as an important environmental cue for the formation of this so-called “peg”. Hideyuki Takahashi from Tohoku University, with colleagues across Japan, investigated the morphology and distribution of a protein called CsPIN1, which is involved in mediating peg development through the plant hormone auxin. The team looked at cucumber seedlings grown on the International Space Station under either microgravity or simulated gravity via centrifugation. Centrifugation directed crosswise to the axis of the seedling led to the correct localization of CsPIN1 in the plant's cells, which could facilitate proper peg formation. The findings could help future astronauts grow food in space.