Effect of phytosiderophores on ⁵⁹Fe absorption and translocation in arsenic-induced chlorosis in rice and barley seedlings
2021
Shaibur, Molla Rahman
In the greenhouse, rice (Oryza sativa L. cv. Akitakomachi) were grown at pH 5.5, treated with 26.8 μM As (arsenite; NaAsO₂) for 14 days. We found that As-induced whitish chlorosis in the fully developed young leaves. Control and As-treated seedlings were fed with 10 μM ⁵⁹Fe in the absence or in the presence of 10 μM PS (phytosiderophores, mugineic acid) for 4 h in the phytotron to observe the efficiency of PS on ⁵⁹Fe absorption and translocation in plants. Absorption and translocation of ⁵⁹Fe increased in control plants fed with PS as compared with those without being fed with PS, indicating that PS effectively elevated ⁵⁹Fe absorption and translocation. In As-treated plants, PS enhanced ⁵⁹Fe absorption by roots but did not enhance ⁵⁹Fe translocation from roots to shoots. In addition, ⁵⁹Fe absorption was lower in As-treated plants as compared to control plants in the absence or presence of PS. In the phytotron, a similar experiment with barley (Hordeum vulgare L. cv. Minorimugi) was conducted. Barley were grown at pH 6.5 treated with 33.5 μM As for 14 days, showing chlorosis, were fed with ⁵⁹Fe in the absence or presence of PS. In control plants, PS enhanced ⁵⁹Fe absorption and translocation similarly to rice. In As-treated barley, PS enhanced ⁵⁹Fe absorption in roots and PS activity enhanced ⁵⁹Fe translocation from roots to shoots. Our results suggested that As repressed or inhibited the system for PS-Fe³⁺ absorption in gramineae under severe As-stress condition, resulting in appearance of Fe chlorosis.
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