ISHS Acta Horticulturae 381: International Symposium on Natural Phenols in Plant Resistance
INVESTIGATION OF CONIFERIN COMPARTMENTATION IN DEVELOPING XYLEM OF CONIFERS DURING LIGNIFICATION |
| Authors: | V. Leinhos, R.A. Savidge |
| Keywords: | cambium, lignification, conifers, coniferin, protoplasts, xylogenesis |
| Abstract:
Coniferin serves as the dominant storage reserve for lignin biosynthetic metabolites in developing xylem of conifers. Understanding lignification requires knowledge about coniferin levels in intracellular compartments. Volumetrically, the two major fluid compartments of plant cells are the vacuole and the cytosol. Both of these can be isolated from intact protoplasts. Protoplasts were isolated from differentiating rays and tracheids of Pinus banksiana and Pinus strobus by incubating freshly harvested tissue in a cellulase-pectinase mixture and purified using a discontinous sucrose-mannitol gradient. More than 70 % of the isolated protoplasts were of small diameter (12–27 μm) had a dense cytoplasm and a large number of vacuoles, suggesting they originated from ray cells. Considerably larger protoplasts (27–65 μm) made up about 25 % of the ptotoplast population. These contained single large vacuoles suggesting they originated from fusiform cells. Using high performance liquid chromatography coniferin was readily detected in protoplasts as well as their respective tissue extracts from both species. On a fresh weight basis, coniferin occured at 1.0–1.6 mM in protoplasts. In mid June, total tissue coniferin could be accounted for by protoplast coniferin content. In late July, the coniferin contents found in protoplasts of both species was lower than those in their respective tissues. | |
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