Growth and development in higher plants under simulated microgravity conditions on a 3-dimensional clinostat

Gravity-controlled asymmetrical transport of auxin regulates a gravitropic response in the early growth stage of etiolated pea (Pisum sativum) epicotyls: studies using simulated microgravity conditions on a three-dimensional clinostat and using an agravitropic mutant, ageotropum

“…1 and 2, when Alaska pea seeds were germinated and grown in a horizontal or an inclined position under 1 g conditions, accumulation of PsIAA4/5 mRNA was asymmetrical in accordance with the asymmetrical elongation growth in the elongated side of the epicotyls. To clarify the important role of the gravity vector in auxin distribution for gravitropic bending, we used a 3D clinostat to simulate microgravity conditions (Hoson et al 1992(Hoson et al , 1997Stankovic et al 1998b;Kraft et al 2000;Shimazu et al 2001;Miyamoto et al 2005). Under such conditions, epicotyls of etiolated Alaska pea seedlings continued to elongate almost straight, with epicotyls in the proximal and distal sides elongating almost symmetrically (Figs.…”

“…The acrylic chamber was kept in a Zip-lock bag at 23.5°C under 1 g or simulated microgravity conditions on a 3D clinostat (CS-2, Nihonikakikai, Osaka, Japan) as reported previously (Shimazu et al 2001;Hoshino et al 2005;Miyamoto et al 2005). For comparison between the proximal and the distal sides of epicotyls to the cotyledons, epicotyls were cut longitudinally into proximal and distal halves after appropriate incubation, frozen in liquid nitrogen and stored at -80°C before use for Northern blot analysis.…”

“…Such morphogenesis observed under microgravity conditions has been designated as automorphosis (Hoson et al 1992;Stankovic et al 1998a). Automorphosis-like growth and development of etiolated pea seedlings was demonstrated to be induced when pea plants are constantly rotated three-dimensionally on a three-dimensional (3D) clinostat (Shimazu et al 2001;Miyamoto et al 2005), suggesting that this device is a valuable tool for simulating microgravity conditions (Hoson et al 1992(Hoson et al , 1997Stankovic et al 1998b;Kraft et al 2000). As well as application of the 3D clinostat to simulate microgravity conditions, mutants showing automorphosis-like growth and development are valuable in understanding how gravity regulates morphogenesis in plants.…”

Auxin Polar Transport and Automorphosis in Plants

“…In the STS-95 space experiment (1998), we also found that etiolated Alaska pea seedlings grown under microgravity conditions in space showed automorphosis, such as epicotyl bending to the direction away far from the cotyledons, changes in the root growth direction, and inhibition of hook formation (Ueda et al, , 2000 similar to that on a 3-D clinostat ( Fig. 1) (Shimazu et al, 2001;Miyamoto et al, 2005a, b). The occurrence of automorphosis on different plant species grown on a 3-D clinostat together with that in space has been summarized by Hoson et al (1992) and Hoson and Soga (2003).…”

“…clinostat, which provides a way to randomize G-stimulation by providing 3-dimansional rotation, has been demonstrated to be a valuable device for simulating microgravity or weightlessness conditions, and intensively used for ground-based experiments (Hoson et al, 1992(Hoson et al, , 1996(Hoson et al, , 1997Kraft et al, 2000;Shimazu et al, 2001;Miyamoto et al, 2005b).…”