Interactions of selenium hyperaccumulators and nonaccumulators during cocultivation on seleniferous or nonseleniferous soil – the importance of having good neighbors
Article first published online: 23 JAN 2012
© 2012 The Authors. New Phytologist © 2012 New Phytologist Trust
Special Issue: Featured papers on ‘Bioenergy trees’
Volume 194, Issue 1, pages 264–277, April 2012
How to Cite
El Mehdawi, A. F., Cappa, J. J., Fakra, S. C., Self, J. and Pilon-Smits, E. A.H. (2012), Interactions of selenium hyperaccumulators and nonaccumulators during cocultivation on seleniferous or nonseleniferous soil – the importance of having good neighbors. New Phytologist, 194: 264–277. doi: 10.1111/j.1469-8137.2011.04043.x
- Issue published online: 24 FEB 2012
- Article first published online: 23 JAN 2012
- Received: 14 October 2011, Accepted: 12 December 2011
- plant–plant interactions;
- •This study investigated how selenium (Se) affects relationships between Se hyperaccumulator and nonaccumulator species, particularly how plants influence their neighbors’ Se accumulation and growth.
- •Hyperaccumulators Astragalus bisulcatus and Stanleya pinnata and nonaccumulators Astragalus drummondii and Stanleya elata were cocultivated on seleniferous or nonseleniferous soil, or on gravel supplied with different selenate concentrations. The plants were analyzed for growth, Se accumulation and Se speciation. Also, root exudates were analyzed for Se concentration.
- •The hyperaccumulators showed 2.5-fold better growth on seleniferous than on nonseleniferous soil, and up to fourfold better growth with increasing Se supply; the nonaccumulators showed the opposite results. Both hyperaccumulators and nonaccumulators could affect growth (up to threefold) and Se accumulation (up to sixfold) of neighboring plants. Nonaccumulators S. elata and A. drummondii accumulated predominantly (88–95%) organic C-Se-C; the remainder was selenate. S. elata accumulated relatively more C-Se-C and less selenate when growing adjacent to S. pinnata. Both hyperaccumulators released selenocompounds from their roots. A. bisulcatus exudate contained predominantly C-Se-C compounds; no speciation data could be obtained for S. pinnata.
- •Thus, plants can affect Se accumulation in neighbors, and soil Se affects competition and facilitation between plants. This helps to explain why hyperaccumulators are found predominantly on seleniferous soils.