ACCUMULATION AND TRANSLOCATION OF SILICON IN RICE AND BEAN PLANTS USING THE ³⁰SI STABLE ISOTOPE

Abstract

The ³⁰Si silicon isotope stable was used for assessing the accumulation and translocation of Si in rice and bean plants grown in labeled nutritive solution. The isotopic silicon composition in plant materials was determined by mass spectrometry (IRMS) using the method based on SiF₄ formation. Considering the total-Si added into nutritive solutions, the quantity absorbed by plants was near to 51% for rice and 15% for bean plants. The accumulated amounts of Si per plant were about 150g in rice and 8.6g in bean. Approximately 70% of the total-Si accumulated was found in leaves. At presented experimental conditions, the results confirmed that once Si is accumulated in the old parts of rice and bean plant tissues it is not redistributed to new parts, even when Si is not supplied to plants from nutritive solution.

Keywords:

• silicon
• stable isotopes
• isotopic determination
• labeled compounds
• mass spectrometry
• plants

ACKNOWLEDGMENTS

Partial financial support and fellowships from Brazilian agencies (FAPESP, CNPq) are greatly appreciated.