| Full text | |
| Author(s): |
Total Authors: 2
|
| Affiliation: | [1] Universidade Federal de Minas Gerais. Instituto de Ciências Biológicas. Departamento de Botânica - Brasil
[2] Universidade Estadual Paulista Júlio de Mesquita Filho. Instituto de Biociências. Departamento de Botânica - Brasil
Total Affiliations: 2
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| Document type: | Journal article |
| Source: | Acta Botanica Brasilica; v. 20, n. 2, p. 471-482, 2006-06-00. |
| Field of knowledge: | Biological Sciences - Botany |
| Abstract | |
Hymenaea stigonocarpa Mart. ex Hayne, known as "jatobá-do-cerrado" has extrafloral nectaries (EFNs), which are reported for the first time in Hymenaea genus. In this research the origin, distribution, structure, and ultrastructure of the EFNs were studied. Samples of leaflets at different developmental stages were collected, fixed and processed by standard methods for analyses at light and electronic microscopes; histochemical tests were employed to determine the nature of secretion products. EFNs are distributed all over leaf blade, more concentrated on the basal and medial thirds of each leaflet. These nectaries are embedded in the mesophyll, show secretory tissue surrounded by an endodermis, and are vascularized by xylem and phloem. EFN secretory activity was exclusively observed in young leaves. The protoderm origins the EFN secretory tissue, the ground meristem originates the endodermis and the procambium originates the vascular tissues. Secretory cells of functional EFNs showed dense cytoplasm, large nucleus, mitochondria, plastids with a poorly developed membrane system, oil drops scattered in the cytosol, dictyosome, and smooth endoplasmic reticulum segments. Secretion was released by cuticle rupture and contains polysaccharides and lipids. (AU) | |
| FAPESP's process: | 00/12469-3 - Morphological, anatomical, histochemical, and ultrastructural studies of cerrado plants (sensu lato) of São Paulo State |
| Grantee: | Silvia Rodrigues Machado |
| Support Opportunities: | BIOTA-FAPESP Program - Thematic Grants |