Application of soft X-ray microradiography to observation of cystoliths in the leaves of various higher plants

• DOI: 10.1007/bf02489544
• Publication Date: 2006-09-19T07:15:03Z
• Authors: Megumi Okazaki; Hiroaki Setoguchi; Harumi Aoki; Shoichi Suga
• Keywords: 0301 basic medicine; 03 medical and health sciences

Soft X-ray microradiography was applied to observation of the cystoliths, calcified bodies of higher plants, in the leaves ofMorus bombycis, Humulus scandens, Ficus elastica, F. retusa (Moraceae),Boehmeria platanifolia, Pilea viridissima (Urticaceae) andMomordica charantia (Cucurbitaceae). It was proved that this technique is useful for examination of the shape, size, distribution and number of cystoliths in fresh leaves. The microradiographs revealed large cigar-shaped cystoliths in the leaf ofP. viridissima, and neighbor-cystoliths in somewhat restricted areas of the leaves ofM. bombycis andH. scandens, and two to seven radially arranged cystoliths in the leaf ofM. charantia. The number of cystoliths per unit area of leaf (nos./cm2) was estimated to be from 1,090 to 3,900 by means of the microradiographs, varying from species to species. The CaCO3 content of the leaf calculated from the volume and number of cystoliths was approximately 0.4 mg/cm2 in all species exceptF. retusa. InF. retusa, it was about 1.06 mg/cm2, the highest value among all species tested. Hand-sections of the leaves showed that the lithocysts were localized in the upper and/or lower epidermis, and they were associated with many photosynthetic cells in all species, suggesting some relationship between CaCO3 deposition in cystoliths and photosynthesis.