Abstract
Salinity is an increasing problem for agricultural production worldwide. The result of low-affinity Na+ uptake is toxic to the cytoplasm of most crop plants. Nevertheless, the pathways for this low-affinity Na+ uptake are still uncertain. In this work we used 22Na+ isotope tracing technology to investigate factors associated with determination of root 22Na+ influx in the salt accumulation halophyte Suaeda maritima. We found that a 2 min of exposure to the 22Na+ labeled uptake solution was optimal for determining 22Na+ influx into excised roots of S. maritima and that 7 min of blotting is suitable in 22Na+ influx experiments. 22Na+ influx did not increase linearly with the increasing external Na+ concentration, in the range tested, of 2 to 300 mM NaCl. But root 22Na+ influx and root Na+ concentration were well correlated. 22Na+ influx into excised roots of S. maritima was not, however, well correlated with the plant size. All the above results indicated further that this 22Na+ isotope influx procedure is a good method for quantify Na+ uptake rate by the roots of the salt accumulation halophyte.
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Acknowledgments
This work was supported by the National Basic Research Program of China (grant No. 2007CB108901) and the National Natural Science Foundation of China (grant No. 30671488 and 30700562). We also thank anonymous reviewers for their constructive comments and suggestions on the manuscript.
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Zhang, JL., Wetson, A.M., Wang, SM. et al. Factors Associated with Determination of Root 22Na+ Influx in the Salt Accumulation Halophyte Suaeda maritima . Biol Trace Elem Res 139, 108–117 (2011). https://doi.org/10.1007/s12011-010-8644-y
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DOI: https://doi.org/10.1007/s12011-010-8644-y