Storage Behavior of Chionanthus retusus Seed and Asynchronous Development of the Radicle and Shoot Apex during Germination in Relation to Germination Inhibitors, Including Abscisic Acid and Four Phenolic Glucosides
Resource
Plant and Cell Physiology 45 (9): 1158-1167
Journal
Plant and Cell Physiology
Journal Volume
45
Journal Issue
9
Pages
1158-1167
Date Issued
2004
Date
2004
Author(s)
Chien, Ching-Te
Shen, Ya-Ching
Zhang, Ruichuan
Chen, Shun-Ying
Yang, Jeng-Chuann
Pharis, Richard P.
Abstract
Studies on seed storage of Chionanthus retusus Lindl. & Paxt. revealed an orthodox behavior, one which showed both desiccation and freezing tolerance. An epicotyl after-ripening dormancy was expressed in C. retusus seeds by slow growth of the shoot apex relative to more rapid growth of the radicle when seeds were germinated at 30/20 degrees C. Although these seeds exhibit radicle protrusion, they must be after-ripened for another 8-10 weeks at 30/20 degrees C in order to obtain normal shoot growth. Removal of the endosperm, however, quickly stimulated cotyledon and shoot emergence without the additional after-ripening. Water-soluble glucoside phenolics, GL-3, Nuzhenide, ligustroside and oleoside dimethyl ester are present at relatively high levels in endosperm of freshly harvested seeds. These glucoside phenolics are excreted from the endosperm during subsequent after-ripening. Embryo and endosperm tissue from seed germinating at 30/20 degrees C (germination being defined by protrusion of the radicle) had a 10 times lower abscisic acid (ABA) content than similar tissues from freshly harvested mature seed. However, no shoot growth occurred even with the 10-fold reduction in ABA and a concomitant increase in endogenous gibberellins A1, A4 and A20. Thus, epicotyl dormancy during the first 8 weeks of after-ripening at 30/20 degrees C may be controlled by factors other than high ABA, i.e., the slow development of the shoot apex following radicle protrusion may be controlled more by high levels of glucoside phenolics than by diminished ABA and elevated GA levels.
SDGs
Publisher
Oxford University Press
File(s)![Thumbnail Image]()
Loading...
Name
13.pdf
Size
583.59 KB
Format
Adobe PDF
Checksum
(MD5):e4eebb8643f2fd863d0ef1d06dcf2876