Transgenic AEQUORIN reveals organ-specific cytosolic Ca2+ responses to anoxia and Arabidopsis thaliana seedlings.
Using the transgenic AEQUORIN system, we showed that the cotyledons and leaves of Arabidopsis thaliana seedlings developed a biphasic luminescence response to anoxia, indicating changes in cytosolic Ca2+ levels. A fast and transient luminescence peak occurred within minutes of anoxia, followed by a second, prolonged luminescence response that lasted 1.5 to 4 h. The Ca2+ channel blockers Gd3+, La3+, and ruthenium red (RR) partially inhibited the first response and promoted a larger and earlier second response, suggesting different origins for these responses. Both Gd3+ and RR also partially inhibited anaerobic induction of alcohol dehydrogenase gene expression. However, although anaerobic alcohol dehydrogenase gene induction occurred in seedlings exposed to water-agar medium and in roots, related luminescence responses were absent. Upon return to normoxia, the luminescence of cotyledons, leaves, and roots dropped quickly, before increasing again in a Gd3+, La3+, ethyleneglycol-bis(beta-aminoethyl ether)-N,N'-tetraacetic acid-, and RR-sensitive fashion.
Sedbrook
J C
JC
Laboratory of Genetics, University of Wisconsin-Madison 53706, USA.
Kronebusch
P J
PJ
Borisy
G G
GG
Trewavas
A J
AJ
Masson
P H
PH
D000331:Aequorin / Q000235:genetics / Q000378:metabolism*; D000426:Alcohol Dehydrogenase / Q000235:genetics; D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism*; D002121:Calcium Channel Blockers / Q000494:pharmacology; D003600:Cytosol / Q000378:metabolism*; D004533:Egtazic Acid / Q000494:pharmacology; D000860:Hypoxia; D008163:Luminescent Measurements; D030821:Plants, Genetically Modified; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism
D002121:Calcium Channel Blockers; D012333:RNA, Messenger; D000331:Aequorin; D004533:Egtazic Acid; D000426:Alcohol Dehydrogenase; D002118:Calcium