An inhibitor of the Ca(2+)-ATPases in the sarcoplasmic and endoplasmic reticula inhibits transduction of the gravity stimulus in cress roots.
Cress (Lepidium sativum L.) roots were treated with 20 microM cyclopiazonic acid (CPA), an inhibitor of the Ca(2+)-transporting ATPases present in the sarcoplasmic/endoplasmic reticulum of animals and the endoplasmic reticulum of plants, in order to investigate its effect on the gravitropic response. Root growth was not significantly reduced by the applied dose of CPA, but the gravitropic response (curvature) was drastically inhibited. We hypothesize that the ER Ca(2+)-ATPase of statocytes is involved in transduction of the gravity stimulus and that CPA disturbs a cytosolic Ca2+ signal necessary for graviperception.
Sievers
A
A
Botanisches Institut, Universitat Bonn, FRG.
Busch
M B
MB
D019607:Brassicaceae / Q000187:drug effects / Q000201:enzymology* / Q000254:growth & development; D015220:Calcium Channels / Q000502:physiology; D000252:Calcium-Transporting ATPases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D002462:Cell Membrane; D004721:Endoplasmic Reticulum / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D018522:Gravitropism / Q000187:drug effects; D018466:Gravity Sensing / Q000187:drug effects; D007211:Indoles / Q000494:pharmacology*; D018517:Plant Roots / Q000187:drug effects* / Q000201:enzymology / Q000254:growth & development; D018087:Plastids / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects*
D015220:Calcium Channels; D004791:Enzyme Inhibitors; D007211:Indoles; D000252:Calcium-Transporting ATPases; C000543:cyclopiazonic acid