Study on Silicon Isotope Tracing for Silica Mineralization in Plants
详细信息
- 责任者：Ding Tiping (Institute of Mineral Resources ; CAGS ; Beijing 100037 ; China) ; Tian Shihong
- 刊名：Acta Geoscientica Sinica
- 出版年：2009
- 卷期：30(2)
- 关键词：硅同位素 ; silicon isotopes ; 同位素示踪法 ; isotopic tracer methods
- 页码：p.129-142
- 图表：15 illus., 2 tables, 73 refs.
- 分类号：0600
- issnNo：ISSN1006-3021
- isbnNo：CN11-3474/P
摘要
A systematic investigation on contents, morphology, and distribution and silicon isotope compositions of silica was undertaken the first time on field grown rice plants and bamboos, as well as on laboratory grown rice plants. It was found that the SiO2 contents in rice plant increased generally from roots, through stem and leaves, to husks, but decreased drastically from husks to grains. Similarly the silica contents in bamboo plant increased also from stem, through branch, to leaves, although decreased slightly from root to stem. The silica was found to occur exclusively in the endodermis cells in the roots of rice and bamboo, but mainly in epidermal cells in their aerial parts (stem, branch, leaves and husks). Large and systematic silicon isotope fractionation was observed among different organs of individual plant of rice and bamboo. The δ30Si value of rice organs decreased from roots to stem, and then increased through leaves, husks and grains. Similarly the δ30Si values of bamboo organs decreased from roots to stem, but then increased from stem, through branch, to leaves. This kind of silicon isotope variation might be caused by isotope fractionation in a Rayleigh process when SiO2 precipitated in stem, branches, leaves and husks gradually from plant fluid. The Si isotope fractionation factor between dissolved Si and precipitated Si is inferred to be 0.9981 in bamboo plant and 0.9996 in rice plant.