Cadmium induces premature xylogenesis in barley roots
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The effect of Cd on H2O2 production, peroxidase (POD) activity and root hair formation were analyzed in barley root. Cd causes a strong H2O2 burst in the root region 0–6 mm behind the root tip. POD activity was activated in root tip and raised toward the root base in Cd treated roots. In situ analyses showed that both elevated H2O2 production and POD activity are localized in the early metaxylem vascular bundles. Cd induces root hair formation in the region 2 to 4 mm behind the root tip that was not detected in control roots. These results suggest that Cd-induced root growth inhibition is at least partially the consequence of Cd-stimulated premature root development involving xylogenesis and root hair formation, which is correlated with shortening of root elongation zone and therefore with root growth reduction.
KeywordsCadmium Hydrogen peroxide Lignification Peroxidase Root growth Root hair
Active oxygen species
We wish to thank Margita Vašková for excellent technical assistance. This work was supported by the Grant agency VEGA, project No 2/4040/04.
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