Getting to the Root of Selenium Hyperaccumulation—Localization and Speciation of Root Selenium and Its Effects on Nematodes
| Autor: | Diana H. Wall, Sirine C. Fakra, Elizabeth A. H. Pilon-Smits, Jose R. Valdez-Barillas, Christine N. Prins, Cecilia Milano de Tomasel, Jennifer J. Cappa, Laura J. Hantzis |
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| Rok vydání: | 2019 |
| Předmět: |
0106 biological sciences
0301 basic medicine Astragalus bisulcatus Perennial plant Soil Science chemistry.chemical_element elemental defense 01 natural sciences lcsh:Chemistry 03 medical and health sciences Dry weight Botany Hyperaccumulator lcsh:Physical geography Earth-Surface Processes biology herbivory Stanleya pinnata biology.organism_classification 030104 developmental biology Nematode lcsh:QD1-999 chemistry Stele lcsh:GB3-5030 Selenium 010606 plant biology & botany |
| Zdroj: | Soil Systems, Vol 3, Iss 3, p 47 (2019) Soil Systems Volume 3 Issue 3 |
| ISSN: | 2571-8789 |
| Popis: | Elemental hyperaccumulation protects plants from many aboveground herbivores. Little is known about effects of hyperaccumulation on belowground herbivores or their ecological interactions. To examine effects of plant selenium (Se) hyperaccumulation on nematode root herbivory, we investigated spatial distribution and speciation of Se in hyperaccumulator roots using X-ray microprobe analysis, and effects of root Se concentration on root-associated nematode communities. Perennial hyperaccumulators Stanleya pinnata and Astragalus bisulcatus, collected from a natural seleniferous grassland contained 100&ndash 1500 mg Se kg&minus 1 root dry weight (DW). Selenium was concentrated in the cortex and epidermis of hyperaccumulator roots, with lower levels in the stele. The accumulated Se consisted of organic (C-Se-C) compounds, indistinguishable from methyl-selenocysteine. The field-collected roots yielded 5&ndash 400 nematodes g&minus 1 DW in Baermann funnel extraction, with no correlation between root Se concentration and nematode densities. Even roots containing > 1000 mg Se kg&minus 1 DW yielded herbivorous nematodes. However, greenhouse-grown S. pinnata plants treated with Se had fewer total nematodes than those without Se. Thus, while root Se hyperaccumulation may protect plants from non-specialist herbivorous nematodes, Se-resistant nematode taxa appear to associate with hyperaccumulators in seleniferous habitats, and may utilize high-Se hyperaccumulator roots as food source. These findings give new insight into the ecological implications of plant Se (hyper)accumulation. |
| Databáze: | OpenAIRE |
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