AbstractGravity affects growth and morphogenesis in higher plants. Recently, it has become clear that hypergravity induces morphological changes such as inhibition of elongation growth and promotion of lateral growth. Some indirect evidence suggests that changes in the cytoplasmic free calcium concentration ([Ca2+]c) play an important role in these hypergravity-induced modifications of growth. However, the hypothetical changes in [Ca2+]c under hypergravity have not been examined. Here, we report the measurement of the [Ca2+]c changes induced by hypergravity stimuli in Arabidopsis seedlings expressing the calcium reporter, aequorin. When the seedlings are subjected to 20g-hypergravity produced by centrifugation, [Ca2+]c transiently increased and decayed exponentially during the hypergravity stimulation. Larger [Ca2+]c-increase was observed when the magnitude of hypergravity was increased up to 300g. The [Ca2+]c-response showed a strong desensitization, and it could not be elicited even 45min after the cessation of the first stimulation. The [Ca2+]c-increase was inhibited by externally applied La3+ or Gd3+, potential mechanosensitive Ca2+-permeable channel inhibitors, suggesting that the hypergravity-induced [Ca2+]c-increase is mediated by the activation of Ca2+-permeable channels in the plasma membrane.
Hypergravity stimulation induces changes in intracellular calcium concentration in Arabidopsis seedlings
Advances in Space Research ; 39 , 7 ; 1190-1197
2006-12-07
8 pages
Article (Journal)
Electronic Resource
English
Hypergravity-induced changes in gene expression in Arabidopsis hypocotyls
Online Contents | 2003
|Hypergravity-Induced Changes in Gene Expression in Arabidopsis Hypocotyls
British Library Conference Proceedings | 2003
|British Library Conference Proceedings | 2005
|