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Iron plaque enhances phosphorus uptake by rice ( Oryza sativa ) growing under varying phosphorus and iron concentrations
Author(s) -
Liang Y.,
Zhu Y.G.,
Xia Y.,
Li Z.,
Ma Y.
Publication year - 2006
Publication title -
annals of applied biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.677
H-Index - 80
eISSN - 1744-7348
pISSN - 0003-4746
DOI - 10.1111/j.1744-7348.2006.00095.x
Subject(s) - shoot , oryza sativa , phosphorus , ferric , adsorption , incubation , iron oxide , chemistry , horticulture , nuclear chemistry , environmental chemistry , zoology , biology , inorganic chemistry , biochemistry , organic chemistry , gene
Both solution culture and pot experiments were performed to investigate (a) the effects of external Fe (II) concentrations and forms on the formation of iron plaque on the roots of rice ( Oryza sativa ) and subsequent P adsorption on iron plaque and shoot P concentrations and (b) the effects of soil moisture regimes on the formation of iron plaque and P adsorption on root surfaces and P accumulation in shoots. The results showed that iron plaque was significantly increased with increasing Fe 2+ concentrations in the solution culture. The amounts of P adsorbed on the iron plaque were increased significantly with external Fe 2+ concentrations. Although shoot P concentration was not significantly affected by Fe 2+ treatment after incubation for 2 days, it was significantly increased in the Fe‐treated plants compared with Fe‐deprived ones after incubation for 4 days. Soil culture experiment showed that the formation of iron plaque on root surfaces was promoted by exogenous iron, with greater amount of iron plaque being formed by addition of ferric hydroxide than of ferric oxide. Phosphorus adsorption on iron plaque also increased with the addition of iron oxides, and increasing soil P increased the amounts of P associated with the iron plaque and shoot P concentration. The amounts of iron plaque were almost sixfold higher under flooding condition than under field capacity condition. Plants pretreated under flooding condition generally had higher shoot P concentrations when they were transplanted to solutions with varying P levels, and this was most pronounced in the treatment with highest solution P concentration. The results suggest that iron plaque acts as a nutrient reservoir for phosphorus in the rhizosphere and helps enhance P acquisition by rice.