Citation
Wu J. L., . and Hao B. Z., . Ultrastructure of Hevea bark on tapping: parenchyma cells in secondary phloem. pp. 137-145. ISSN 0127-7065
Abstract
The parenchyma cells of secondary phloem in the trunk of Hevea brasiliensis were observed using transmission electron microscopy. In an untapped tree the axial parenchyma cells and ray parenchyma cells rather than the companion cells are mainly storage cells which contain varied reserves and show less activity in metabolism. In addition to the cells with vacuolar proteins in a fibrous form reported before other axial parenchyma cells were found containing thicker diameter fibrils in the central vacuoles. In a tapped tree the parenchyma cells near the tapping cut underwent many ultrastructural changes: decrease of reserves which include starch grains vacuolar proteins in the protein-storing cells and phytoferritin in plastids; formation of plasmatubules and related structures and the myelin-like structures; occurrence of electron-dense materials outside the protoplast; increased accumulation of tannins. These changes were found in axial parenchyma cells and ray parenchyma cells and not in the companion cells except for the formation of plasmatubules and related structures. All the changes suggest the activation of metabolism in the parenchyma cells.
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Abstract
The parenchyma cells of secondary phloem in the trunk of Hevea brasiliensis were observed using transmission electron microscopy. In an untapped tree the axial parenchyma cells and ray parenchyma cells rather than the companion cells are mainly storage cells which contain varied reserves and show less activity in metabolism. In addition to the cells with vacuolar proteins in a fibrous form reported before other axial parenchyma cells were found containing thicker diameter fibrils in the central vacuoles. In a tapped tree the parenchyma cells near the tapping cut underwent many ultrastructural changes: decrease of reserves which include starch grains vacuolar proteins in the protein-storing cells and phytoferritin in plastids; formation of plasmatubules and related structures and the myelin-like structures; occurrence of electron-dense materials outside the protoplast; increased accumulation of tannins. These changes were found in axial parenchyma cells and ray parenchyma cells and not in the companion cells except for the formation of plasmatubules and related structures. All the changes suggest the activation of metabolism in the parenchyma cells.
Additional Metadata
| Item Type: | Article |
|---|---|
| AGROVOC Term: | Hevea brasiliensis |
| AGROVOC Term: | Electron microscopy |
| AGROVOC Term: | Tapping |
| AGROVOC Term: | Parenchyma |
| AGROVOC Term: | Phloem |
| AGROVOC Term: | Electron microscopy |
| AGROVOC Term: | Seed planting |
| AGROVOC Term: | Ribosomes |
| AGROVOC Term: | Dictyosomes |
| AGROVOC Term: | Mitochondria |
| Depositing User: | Ms. Suzila Mohamad Kasim |
| Last Modified: | 24 Apr 2025 06:28 |
| URI: | http://webagris.upm.edu.my/id/eprint/23438 |
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