NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
On the role of calcium in indole-3-acetic acid movement and graviresponse in etiolated pea epicotylsTo determine whether Ca2+ plays a special role in the early graviresponse of shoots, as has been reported for roots, we treated etiolated pea epicotyls with substances known to antagonize Ca2+ (La3+), to remove Ca2+ from the wall (spermidine, EGTA), to inhibit calmodulin mediated reactions (chlorpromazine), or to inhibit IAA transport (TIBA). We studied the effect of these substances on IAA and Ca2+ uptake into 7 mm long subapical 3rd internode etiolated pea epicotyl sections and pea leaf protoplasts, on pea epicotyl growth, and graviresponse and on lateral IAA redistribution during gravistimulation. Our results support the view that adequate Ca2+ in the apoplast is required for normal IAA uptake, transport and graviresponse. Experiments with protoplasts indicate that Ca2+ may be controlling a labile membrane porter, possibly located on the external surface of cell membrane, while inhibitor experiments suggest that calmodulin is also implicated in both the movement of IAA and graviresponse. Since a major transfer of Ca2+ through free space during graviresponse has not yet been demonstrated, and since inhibition of calcium channels does not affect IAA redistribution (Migliaccio and Galston, 1987, Plant Physiology 85:542), we conclude that no clear evidence links prior Ca2+ movement with IAA redistribution during graviresponse in stems.
Document ID
20040089569
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Migliaccio, F.
(Yale University New Haven, CT 06511-8112, United States)
Galston, A. W.
Date Acquired
August 21, 2013
Publication Date
January 1, 1989
Publication Information
Publication: Plant growth regulation
Volume: 8
ISSN: 0167-6903
Subject Category
Life Sciences (General)
Funding Number(s)
CONTRACT_GRANT: NSG-7290
Distribution Limits
Public
Copyright
Other
Keywords
Non-NASA Center
NASA Discipline Number 29-20
NASA Discipline Plant Biology
NASA Program Space Biology

Available Downloads

There are no available downloads for this record.
No Preview Available