The subcellular distribution and biosynthesis of castaprenols and plastoquinone in the leaves of Aesculus hippocastanum.
Intact chloroplasts and cell walls were prepared from horse-chestnut leaves that had previously metabolized [2-(14)C]mevalonate. The bulk of the castaprenols and plastoquinone-9 was found within the chloroplasts. The remaining portion of the castaprenols was associated with the cell-wall preparation whereas that of the plastoquinone-9 was probably localized in the soluble fraction of the plant cell. The (14)C content of these compounds of different cell fractions indicated the presence of polyisoprenoid-synthesizing activity both inside and outside the chloroplasts. This was confirmed by the relative incorporation of (14)C when ultrasonically treated and intact chloroplasts were incubated with [2-(14)C]mevalonate. As the leaves aged (on the tree) an increase in extraplastidic castaprenols and plastoquinone-9, together with associated synthesizing activities, was observed.
D000438:Alcohols / Q000378:metabolism*; D002247:Carbon Isotopes; D002473:Cell Wall / Q000378:metabolism*; D002736:Chloroplasts / Q000378:metabolism*; D002855:Chromatography, Thin Layer; D066298:In Vitro Techniques; D008798:Mevalonic Acid / Q000378:metabolism*; D010946:Plants, Medicinal / Q000166:cytology / Q000378:metabolism*; D011809:Quinones / Q000378:metabolism*; D013729:Terpenes / Q000378:metabolism*; D014465:Ultrasonics
D000438:Alcohols; D002247:Carbon Isotopes; D011809:Quinones; D013729:Terpenes; D008798:Mevalonic Acid