Author
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ILARSLAN, HILAL - IOWA STATE UNIVERSITY |
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Palmer, Reid |
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HORNER, HARRY - IOWA STATE UNIVERSITY |
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Submitted to: National Biology Congress
Publication Type: Abstract Only Publication Acceptance Date: 7/1/1998 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: Developing soybean seeds accumulate very large amounts of calcium (Ca) oxalate crystals. These crystals, isolated from ovules and seeds, were a mixture of kinked and straight prismatic twins. X-ray diffraction and polarizing microscopy identified them as Ca oxalate monohydrate. Ca oxalate crystals are a common feature of the integuments and embryo cotyledons in normal developing ovules and seeds (-ld to +60d after anthesis). The integument crystals are oriented with their long axes perpendicular to the long axis of the enlarging seeds. The crystals continue to increase in number for sometime as the seeds develop. Initiation of crystals within cell vacuoles coincides with appearance of dense bodies, membrane whorls, vesicles, and elongated tubule-like bodies. The dense bodies, whorls, and tubule-like bodies initially assume circular shapes in section, and expand and disappear as crystals form. In early seed development, large vacuoles in the inner integument containing these structures become angular, mimicking future crystal shapes. As crystals grow, carbohydrate walls form around them, and these crystal walls eventually fuse with the primary cell walls. The enlarging embryo presses the integuments, crushing most of them. The included crystals disappear and new ones appear in the cotyledons. Preliminary results indicate that the crystals may function as calcium storage for future use by the rapidly enlarging embryo and the derived oxalate may be involved in seed storage protein synthesis. |
