Calcium oxalate crystal production and density at different phenological stages of Glycine max L. plants from the southeast of the Pampean Plain, Argentina

BORRELLI NATALIA; OSTERRIETH MARGARITA; BENVENUTO MARÍA LAURA

PLANT BIOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2016 vol. 18 p. 1016 - 1024

1435-8603

Glycine max L. (soybean) is one of the major crops of the world. Although the process of iomineralization was reported in some organs of soybean, we are now reporting the description and quantification of calcium oxalate crystals in all the vegetative and reproductive organs of soybean during its life cycle, as they act as an important source of calcium to the soil, once the harvesting process is finished. Through diaphanisation, cross sectioning and optical and scanning electron microscopy analysis of the organs, the morphology, size and location of the crystals were identified. In addition, crystal density (nº crystals/mm2) and the input of crystals per cycle to soil (nº crystals. ha-1) were calculated. Soybean produced prismatic calcium oxalate crystals, generally associated with vascular bundles, in all vegetative and reproductive organs, resulting in a potencial transfer to the soil of 81.39 x107 crystals. ha-1 along its life cycle. Pods were the organs with higher calcium oxalate crystal production (1112.7±384.6 crystals/mm2), but with the smaller size (12.3±2.1μm length). However, cotyledons were the organs that produce the larger crystals (21.3±3.5μm length), but in lesser amounts (150.9±64.4 crystals/mm2). In leaves, although the crystal size did not differ between vegetative to reproductive stages (14.5±4.2 and 14.5±4 μm length, respectively), the crystal density increased (293.2 and 409 crystals/mm2, respectively). These results will contribute to the knowledge of the amount of calcium oxalate crystals involved in the process of Ca-recycling through cultivated vegetation in fields from humid plains in medium latitude,therefore they have biological, botanical, biogeochemical and pedological relevance.