Abstract
Basipetal-hypergravity stimuli inhibit elongation growth of azuki bean (Vigna angularis Ohwi et Ohashi) epicotyls by decreasing the cell wall extensibility via an increase in the molecular mass of xyloglucans [Soga et al. (1999) Plant Cell Physiol. 40: 581-585]. However, how plants respond to hypergravity stimuli in other direction has not been elucidated. In the present study, we examined the effects of basipetal-, horizontal- and acropetal-hypergravity stimuli on growth and the cell wall properties of azuki bean seedlings. Horizontal- and acropetal-hypergravity inhibited elongation growth of epicotyls by decreasing the cell wall extensibility, as did basipetal-hypergravity. Hypergravity stimuli in all directions increased the weight-average molecular mass of xyloglucans. This study revealed that growth inhibition by hypergravity is not dependent on the direction of hypergravity stimuli in azuki bean epicotyls.
