Uptake and Translocation of Arsenic and Phosphorus in pho2 Mutant and Wild Type of Arabidopsis thaliana

ABSTRACT

A pot experiment was conducted in a growth chamber to investigate the difference in arsenic (As) uptake and translocation by the pho2 mutant and wild type (WT) of Arabidopsis thaliana (L.) Heynh. The pho2 mutant had higher shoot phosphorus (P) and As concentrations than did WT, but had lower shoot P uptake and similar total shoot As uptake relative to WT because of its smaller shoot biomass. Similarly, root P uptake and As uptake were lower in pho2, but pho2 had similar root P and slightly higher As concentrations than those of WT. Furthermore, specific P and As uptake and P and As translocation from roots to shoots in pho2 were higher than in WT. The results indicate that a small portion of As may have been co-translocated with P from roots to shoots. Addition of 10 mg As kg^{− 1} enhanced the growth of WT without P addition. Addition of 10 mg P kg^{− 1} promoted plant yield and As uptake, and further addition up to 40 mg P kg^{− 1} reduced shoot and root As concentrations. The results indicate that the overall effect of phosphate on As accumulation in the plants may be related to competition between P and As on the surfaces of soil particles and plant roots.

Keywords:

• uptake
• Arabidopsis
• arsenic
• pho2
• phosphate
• translocation

ACKNOWLEDGMENTS

We thank Dr. E. Delhaize (CSIRO, Australia) for kindly providing seeds of pho2 and WT of A. thalinana. The work was financially supported by the Natural Science Foundation of China (40225002), the Ministry of Science and Technology of China (2002CB410808), and the Chinese Academy of Sciences (Hundred Talent Program).