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1-Aminocyclopropane-1-carboxylic acid and abscisic acid during the germination of sugar beet (Beta vulgaris L.): a comparative study of fruits and seeds.
- Source :
-
Journal of experimental botany [J Exp Bot] 2007; Vol. 58 (11), pp. 3047-60. Date of Electronic Publication: 2007 Aug 30. - Publication Year :
- 2007
-
Abstract
- The control of sugar beet (Beta vulgaris L.) germination by plant hormones was studied by comparing fruits and seeds. Treatment of sugar beet fruits and seeds with gibberellins, brassinosteroids, auxins, cytokinins, and jasmonates or corresponding hormone biosynthesis inhibitors did not appreciably affect radicle emergence of fruits or seeds. By contrast, treatment with ethylene or the ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC) promoted radicle emergence of fruits and seeds. Abscisic acid (ABA) acted as an antagonist of ethylene and inhibited radicle emergence of seeds, but not appreciably of fruits. High endogenous contents of ACC and of ABA were evident in seeds and pericarps of dry mature fruits, but declined early during imbibition. ABA-treatment of seeds and fruits induced seed ACC accumulation while ACC-treatment did not affect the seed ABA content. Transcripts of ACC oxidase (ACO, ethylene-forming enzyme) and ABA 8'-hydroxylase (CYP707A, ABA-degrading enzyme) accumulate in fruits and seeds upon imbibition. ABA and ACC and the pericarp did not affect the seed CYP707A transcript levels. By contrast, seed ACO transcript accumulation was promoted by ABA and by pericarp removal, but not by ACC. Quantification of the endogenous ABA and ACC contents, ABA and ACC leaching, and ethylene evolution, demonstrate that an embryo-mediated active ABA extrusion system is involved in keeping the endogenous seed ABA content low by 'active ABA leaching', while the pericarp restricts ACC leaching during imbibition. Sugar beet radicle emergence appears to be controlled by the pericarp, by ABA and ACC leaching, and by an ABA-ethylene antagonism that affects ACC biosynthesis and ACO gene expression.
- Subjects :
- Abscisic Acid metabolism
Amino Acid Oxidoreductases metabolism
Amino Acids, Cyclic metabolism
Beta vulgaris drug effects
Beta vulgaris growth & development
Cyclopentanes pharmacology
Cytokinins pharmacology
Ethylenes pharmacology
Fruit anatomy & histology
Fruit drug effects
Fruit growth & development
Gibberellins pharmacology
Indoleacetic Acids pharmacology
Oxylipins pharmacology
Plant Growth Regulators antagonists & inhibitors
Plant Proteins metabolism
RNA, Messenger metabolism
Seeds anatomy & histology
Seeds drug effects
Seeds growth & development
Abscisic Acid pharmacology
Amino Acids, Cyclic pharmacology
Beta vulgaris metabolism
Germination drug effects
Plant Growth Regulators pharmacology
Subjects
Details
- Language :
- English
- ISSN :
- 0022-0957
- Volume :
- 58
- Issue :
- 11
- Database :
- MEDLINE
- Journal :
- Journal of experimental botany
- Publication Type :
- Academic Journal
- Accession number :
- 17761730
- Full Text :
- https://doi.org/10.1093/jxb/erm162