| Abstract Detail
Organelle Biology Schmidt, Monica [1], Herman, Eliot [2]. Suppression Of Soybean Oleosin Results In Malformation And Aggregation Of Oil Bodies Into Organelle Complexes. Soybeans are produced for their oil and protein content. Soybean seed oil is sequestered during seed maturation into discrete ER-derived organelles bounded by a half-unit phospholipid membrane into which is embedded oleosin proteins encasing the organelle in protein. Oleosins are found associated with seed and pollen oil bodies, while fruit oil bodies possess only the phospholipids membrane without any additional proteins. The existence of oil bodies without proteins appears to indicate that oleosins have a role in events after the formation of the organelle. The association of oleosins only with oil bodies contained in cells that undergo developmentally regulated desiccation and hydration has led to the proposal that oleosins prevent oil aggregation in the drying cell. Using RNAi technology, an essentially complete suppression of the immunologically detectable oleosin has been obtained. Specifically, an RNAi construct was transformed into soybean through somatic embryogenesis and biolistics, and it contained an oleosin sequence-specific hairpin loop driving by the oleosin seed-specific promoter. The resulting seeds have been assayed structurally with light and electron microscopy/cryofixation and proteomics. Two-dimensional gel analysis of the oleosin suppressed soybeans show few changes in the seed proteome. In contrast, light microscopy and high pressure cryfixed EM material of maturing soybean seeds show that the oil bodies are formed and remain in large interconnected complexes of oil bodies widely varying in size and aggregated with the ER. On desiccation, the oil bodies aggregated into massive oil bodies resulting in cellular disruption and a low germination rate. These results indicate that oleosins have a role in mediating the correct formation of soybean oil bodies.
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1 - Donald Danforth Plant Science Center, 975 N. Warson Rd, St. Louis, MO, 63132, US
2 - USDA/ARS at Donald Danforth Plant Science Center, Plant Genetics Research Unit
Keywords:
Oleosin RNAi
Soybean.
Presentation Type: Plant Biology Abstract
Session: P
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM
Number: P18020
Abstract ID:1149 |
