Abstract:
Hydroponic barley (Hordeum vulgare L. cv. minorimugi) was treated with 10 μM arsenic (As) together with 500, 250, 50 and 0 μM phosphorus (P) for 14 days to observe the response of the seedlings. The plants were also treated with 0 μM As + 0 μM P. Iron (Fe)-plaque was visible in the roots under As-treated and P-depleted conditions. The intensity of reddish coloration in the roots decreased with increasing P in the media. However, reddish coloration was not found in the absence of both As and P. The results show that both As and P played a vital role in the formation of Fe-plaque. Additionally, Fe-plaque formation was dependent on the concentration of P in the media. Iron concentration in the roots of the As treated plants without P was higher than that observed in the roots treated with 0 μM As + 0 μM P which suggests that As may have been adsorbed with Fe on the surface of roots, forming Fe-plaque. Arsenic concentration in the shoots and the roots was low under 500 and 250 μM P conditions while high under 50 and 0 μM P conditions. It was found that a higher concentration of P (50 μM; 5 times of As level) was required in the medium to reduce As concentration in the plant tissues.
