Journal
PLANT SIGNALING & BEHAVIOR
Volume 1, Issue 2, Pages 52-58Publisher
TAYLOR & FRANCIS INC
DOI: 10.4161/psb.1.2.2432
Keywords
actin cytoskeleton; gravisensing; graviresponding; root cap
Categories
Funding
- Deutsches Zentrum fur Luft- und Raumfahrt (DLR Koln/Bonn, Germany) [50 WB 9995, 50 WB 0434]
- European Space Agency (ESA/ESTEC) [AO-99-098]
- Ente Cassa di Risparmio di Firenze (Italy)
- Slovak Academy of Sciences, Grant Agency VEGA, Bratislava, Slovakia [2/5085/25]
Ask authors/readers for more resources
The dynamic actin cytoskeleton has been proposed to be linked to gravity sensing in plants but the mechanistic understanding of these processes remains unknown. We have performed detailed pharmacological analyses of the role of the dynamic actin cytoskeleton in gravibending of maize (Zea mays) root apices. Depolymerization of actin filaments with two drugs having different mode of their actions, cytochalasin D and latrunculin B, stimulated root gravibending. By contrast, drug-induced stimulation of actin polymerization and inhibition of actin turnover, using two different agents phalloidin and jasplakinolide, compromised the root gravibending. Importantly, all these actin drugs inhibited root growth to similar extents suggesting that high actin turnover is essential for the gravity-related growth responses rather than for the general growth process. Both latrunculin B and cytochalasin D treatments inhibited root growth but restored gravibending of the decapped root apices, indicating that there is a strong potential for effective actin-mediated gravity sensing outside the cap. This elusive gravity sensing outside the root cap is dependent not only on the high rate of actin turnover but also on weakening of myosin activities, as general inhibition of myosin ATPases induced stimulation of gravibending of the decapped root apices. Collectively, these data provide evidence for the actin turnover-mediated gravity sensing outside the root cap.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available