Purification of gibberellic acid-induced lysosomes from wheat aleurone cells.
Using isopycnic density gradient centrifugation, lysosomes were concentrated in a single region of a sucrose-Ficoll gradient (p = 1-10 g cm-3), well separated from most other cell organelles. Gibberellic acid-induced lysosomes were found to be rich in alpha-amylase and protease but not ribonuclease. The lysosomal band also contained a majority of the NADH2-cytochrome c reductase, a marker enzyme for endoplasmic reticulum, found in the gradient. Examination of electron micrographs revealed that a purified band of lyosomes contained at least 3 vesicle types, ranging in size from 0-1 to 0-5 mum. The significance of these findings to proposed mechanisms of action of gibberellic acid is discussed.
D000681:Amylases / Q000378:metabolism; D002458:Cell Fractionation; D002500:Centrifugation, Isopycnic; D003579:Cytochrome Reductases / Q000378:metabolism; D005875:Gibberellins; D008247:Lysosomes / Q000201:enzymology / Q000648:ultrastructure; D010447:Peptide Hydrolases / Q000378:metabolism; D012260:Ribonucleases / Q000378:metabolism; D012639:Seeds / Q000648:ultrastructure*; D013347:Subcellular Fractions / Q000201:enzymology; D014908:Triticum
D005875:Gibberellins; D003579:Cytochrome Reductases; D012260:Ribonucleases; D000681:Amylases; D010447:Peptide Hydrolases