Preparative procedures markedly influence the appearance and structural integrity of protein storage vacuoles in soybean seeds.
In legumes, vacuoles serve as the final depository for storage proteins. The protein storage vacuoles (PSVs) of soybean contain electron-transparent globoid regions in which phytic acid ( myo-inositol-1,2,3,4,5,6-hexakisphosphate) is sequestered. This paper reports the effect of preparative procedures on the appearance and ultrastructural integrity of PSVs in soybeans. Electron microscopy examination of both developing and mature soybean seeds that were postfixed with osmium tetroxide revealed PSVs that had a homogeneous appearance with very few globoid crystals dispersed in them. Numerous electron-dense lipid bodies were readily seen in these cells. Omission of osmium tetroxide strikingly altered the appearance of PSVs and aided the visualization of the location of the globoids in the PSVs. In contrast to the osmicated tissue, lipid bodies appeared as electron-transparent spheres. The choice of dehydration reagent or staining procedure had little influence on the appearance of the PSVs. The results of this study demonstrate the profound effect of osmium tetroxide on the appearance and structural integrity of PSVs in soybean.
Krishnan
Hari B
HB
Plant Genetics Research Unit, Agricultural Research Service, U.S. Department of Agriculture, and Plant Science Division, University of Missouri, Columbia, Missouri 65211, USA. KrishnanH@missouri.edu
D005404:Fixatives / Q000494:pharmacology; D046529:Microscopy, Electron, Transmission / Q000379:methods*; D009993:Osmium Tetroxide / Q000494:pharmacology; D012639:Seeds / Q000187:drug effects / Q000254:growth & development / Q000648:ultrastructure*; D030262:Soybean Proteins / Q000032:analysis; D013025:Glycine max / Q000187:drug effects / Q000648:ultrastructure*; D013048:Specimen Handling / Q000379:methods; D013194:Staining and Labeling / Q000379:methods; D014617:Vacuoles / Q000187:drug effects* / Q000648:ultrastructure*
D005404:Fixatives; D030262:Soybean Proteins; D009993:Osmium Tetroxide