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ARS Home » Midwest Area » Ames, Iowa » Corn Insects and Crop Genetics Research » Research » Publications at this Location » Publication #117592
Title: CALCIUM OXALATE CRYSTALS IN DEVELOPING SOYBEAN OVULES

Author
item ILARSLAN, HILAL - ANKARA UNIVERSITY, TURKEY
item Palmer, Reid
item HORNER, HARRY - IOWA STATE UNIVERSITY

Submitted to: Annals of Botany
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/15/2001
Publication Date: N/A
Citation: N/A

Interpretive Summary: Calcium oxalate crystals occur in many plant species. The origin and function of calcium oxalate crystals is not fully understood. Kidney stones and bladder stones in humans are calcium oxalate. The objective of this research was to study crystal development in soybean beginning before ovule fertilization until physiological maturity. Crystal mass increases until about 16 days after fertilization, then decreases. Calcium oxalate crystal formation and disappearance follow developmental patterns. Our results suggest that calcium deposits serve as a Ca storage function. The oxalate could be involved in seed storage protein synthesis. This work is useful to scientists studying calcium deposits in plants.

Technical Abstract: Young soybean seeds contain large amounts of calcium oxalate (CaOx) monohydrate crystals during development. A test for Ca and CaOx indicated deposits and crystals initially occurred in the funiculus, where a single vascular bundle enters the seed. Crystals formed in the integuments until embryo enlarged enough to crush the inner portion of the inner integument. Crystals then appeared in the developing cotyledon tissues and embryo axis The crystals formed in cell vacuoles. Dense bodies and membrane complexes were evident in the funiculus. In the inner integument, vacuoles assumed t shape of the future crystals. This presumed predetermined crystal mold is reported here for the first time for soybean seeds. As crystals in each tissue near maturity, a wall forms around each crystal. This intracellular crystal wall becomes contiguous with the cell wall. Integument crystals remain visible until the enlarging embryo crushes the integuments, then the edisappear. A related study revealed that the highest percentage of oxalat dry mass was reached in the developing + 16-d (post-fertilization) seeds, a then decreased during late seed maturation. CaOx formation and disappearan are an integral part of developing soybean seeds. Our results suggest that deposits and crystals serve as a Ca storage function for the rapidly enlarg embryos. The oxalate, derived from one or more possible metabolic pathways could be involved in seed storage protein synthesis.