Interaction of phenanthrene and potassium uptake by wheat roots: a mechanistic modelReportar como inadecuado

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BMC Plant Biology

, 13:168

Biochemistry and physiology


BackgroundPolycyclic aromatic hydrocarbons PAHs are potentially carcinogenic, mutagenic and toxic to both human and non-human organisms. Dietary intake of PAHs is a dominant route of exposure for the general population where food crops are a major source of dietary PAHs. Over 20% of main food crops contain PAHs that exceed the control limits in China. However, the mechanisms on PAH accumulation in crops are not well understood.

ResultsHere we report the physiological mechanism of potassium K-stimulated uptake of phenanthrene PHE, a model PAH in wheat. PHE uptake is stimulated by the external K. The addition of blockers tetraethlyammonium and barium for K channels does not suppress the process, suggesting that K channels are not involved. The introduction of PHE and K elicits a much greater depolarization in root cell membrane potential than that of either PHE or K. K activates the plasma membrane proton H-ATPase in a K-dependent manner. The pattern is quite similar to that in PHE uptake in the presence of K. The external medium pH treated with PHE and K is higher than that with K, and lower than that with PHE, indicating that H pump involves in the interaction between PHE and K uptake.

ConclusionsTherefore, it is concluded that a K influx-H efflux reaction is coupled with the transport of PHE into wheat root cells. Our results provide a novel insight into the PHE uptake by crop roots.

KeywordsPhenanthrene Plasma membrane H-ATPase Polycyclic aromatic hydrocarbons Potassium Wheat root uptake AbbreviationsANOVAAnalysis of variance

Ba2+Barium ion

fr wtFresh weight


HATSHigh-affinity transport system

HPLCHigh performance liquid chromatography

K+Potassium ion

LATSLow-affinity transport system

MES2-N-morpholinoethanesulfonic acid

PAHsPolycyclic aromatic hydrocarbons


PiInorganic P

SDStandard deviation

TEA+Tetraethlyammonium ion.

Electronic supplementary materialThe online version of this article doi:10.1186-1471-2229-13-168 contains supplementary material, which is available to authorized users.

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Autor: Xinhua Zhan - Xiao Liang - Tinghui Jiang - Guohua Xu


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