Gravity-regulated localization of PsPIN1 is important for polar auxin transport in etiolated pea seedlings: Relevance to the International Space Station experiment

Publication date: Available online 2 July 2019Source: Life Sciences in Space ResearchAuthor(s): Motoshi Kamada, Mariko Oka, Riko Inoue, Yayoi Fujitaka, Kensuke Miyamoto, Eiji Uheda, Chiaki Yamazaki, Toru Shimazu, Hiromi Sano, Haruo Kasahara, Tomomi Suzuki, Akira Higashibata, Junichi UedaAbstractTo clarify the mechanism of gravity-controlled polar auxin transport, we conducted the International Space Station (ISS) experiment “Auxin Transport” (identified by NASA's operation nomenclature) in 2016 and 2017, focusing on the expression of genes related to auxin efflux carrier protein PsPIN1 and its localization in the hook and epicotyl cells of etiolated Alaska pea seedlings grown for three days in the dark under microgravity (μg) and artificial 1 g conditions on a centrifuge in the Cell Biology Experimental Facility (CBEF) in the ISS, and under 1 g conditions on Earth. Regardless of gravity conditions, the accumulation of PsPIN1 mRNA in the proximal side of epicotyls of the seedlings was not different, but tended to be slightly higher as compared with that in the distal side. 2,3,5-Triiodobenzoic acid (TIBA) also did not affect the accumulation of PsPIN1 mRNA in the proximal and distal sides of epicotyls. However, in the apical hook region, TIBA increased the accumulation of PsPIN1 mRNA under μg conditions as compared with that under artificial 1 g conditions in the ISS. The accumulation of PsPIN1 proteins in epicotyls determined by western blotting was almost parallel to t...

Source: Life Sciences in Space Research - July 3, 2019 Category: Biology Source Type: research