Observations on the development of the foliar secretory cavities of Porophyllum lanceolatum (Asteraceae)
作者:
Walkyria R. Monteiro,
Marília de Moraes Castro,
Abraham Fahn,
Waldir Caldeira,
期刊:
Nordic Journal of Botany
(WILEY Available online 1995)
卷期:
Volume 15,
issue 1
页码: 69-76
ISSN:0107-055X
年代: 1995
DOI:10.1111/j.1756-1051.1995.tb00124.x
出版商: Blackwell Publishing Ltd
数据来源: WILEY
摘要:
The lipophilic secretory cavities observed in the leaf ofPorophyllum lanceolatum(Asteraceae) are scattered throughout the lamina and around its crenate margins. In the young leaf the cavities are initiated, and their development completed, while the surrounding tissues are still at early stages of differentiation. The cavity lumen has a lysigenous origin. Cell lysis, expansion of the developing leaf and, probably, the pressure exerted by the accumulation of secretory products, are believed to account for the gradual enlargement of the lumen. Concomitantly with ctll disintegration, which occurs throughout development, divisions take place in all cells of the gland. A mature cavity has a multilayered epithelium. Histochemical tests for RNA, proteins, phenolics and pectic polysaccharides revealed intense staining of the content of the epithelial cells in the early stages of cavity development, and a decrease in staining towards its maturity. Staining for lipids is intense in all developmental stages. Tests on the material observed in the lumen of mature cavities, show positive results for lipids, pectic polysaccharides and phenolics.
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