Effect and localization of phenanthrene in maize roots
2016
DUPUY, Joan | Leglize, Pierre | Vincent, Quentin | Zelko, Ivan | Mustin, Christian | Ouvrard, Stéphanie | Sterckeman, Thibault
Polycyclic aromatic hydrocarbons (PAHs) have a toxic effect on plants, which limits the efficiency ofphytomanagement of contaminated soils. The mechanisms underlying their toxicity are not fully understood.A cultivation experiment was carried out with maize, used as model plant, exposed to sandspiked with phenanthrene (50 or 150 mg kg 1 dw). Epi-fluorescence microscopic observation of rootsections was used to assess suberization of exodermis and endodermis and phenanthrene localizationalong the primary root length. For 10 days of cultivation, exodermis and endodermis suberization ofexposed maize was more extensive. However, after 20 days of exposure, exodermis and endodermis ofnon-exposed roots were totally suberized, whilst PHE-exposed roots where less suberized. Earlyextensive suberization may act as barrier against PHE penetration, however longer exposure inhibits rootmaturation. Phenanthrene patches were located only near suberized exodermis and endodermis, whichmay therefore act as retention zones, where the hydrophobic phenanthrene accumulates during its radialtransport.
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