Structure and ultrastructure of leaf and calyx glands in Galphimia brasiliensis (Malpighiaceae)

Citation
Ma. Castro et al., Structure and ultrastructure of leaf and calyx glands in Galphimia brasiliensis (Malpighiaceae), AM J BOTANY, 88(11), 2001, pp. 1935-1944
Citations number
24
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Plant Sciences
Journal title
AMERICAN JOURNAL OF BOTANY
ISSN journal
0002-9122 → ACNP
Volume
88
Issue
11
Year of publication
2001
Pages
1935 - 1944
Database
ISI
SICI code
0002-9122(200111)88:11<1935:SAUOLA>2.0.ZU;2-Z
Abstract
The present study describes the anatomical structure of calyx and leaf glan ds in Galphimia brasiliensis and analyzes the mechanism of secretion. The g lands are marginal and suprabasal, cup-shaped, sessile, and scarcely visibl e with the naked eye. Light microscopy reveals the following features: a th in, smooth cuticle; unistratified secretory cells; subglandular parenchyma; and vascular bundle supply composed of phloem and xylem with abundant drus es of calcium oxalate. Transmission electron microscopy reveals the presenc e of secretory cells with conspicuous nuclei, dense cytoplasm, lipid drople ts, numerous vesicles, mitochondria, Golgi, rough endoplasmic reticulum (RE R), and elongated plastids with osmiophilic contents. The secretion reaches the apoplastic space and accumulates beneath the cuticle. Finally, the vis cous, translucent exudate is eliminated by mechanical rupture of the cuticl e. Histochemical analysis confirms that lipids are the main constituent. Sm all amounts of polysaccharides were also identified.