Oxford University Press (OUP) Acta Medica Okayama 0032-0781 66 7 2025 Oxygen supply is a prerequisite for response to aluminum in cultured cells of tobacco (Nicotiana tabacum) 1044 1060 EN Yoshiyuki Tsuchiya Institute of Plant Science and Resources, Okayama University Maki Katsuhara Institute of Plant Science and Resources, Okayama University Takayuki Sasaki Institute of Plant Science and Resources, Okayama University Yoko Yamamoto Institute of Plant Science and Resources, Okayama University Responses to aluminum (Al) were investigated in tobacco cells (cell line SL) in a calcium-sucrose solution for up to 24 h under shaking (aerobic) condition. Microarray analysis of upregulated and downregulated genes under Al exposure and following Gene Ontology (GO) enrichment analysis of biological process category revealed only one GO term to be enriched for the upregulated genes, “response to chitin,” annotated with genes encoding transcription factors (NtERF1 and NtMYB3) and MAP kinase (WIPK), and nine GO terms for the downregulated genes, including “cell wall loosening” and “lipid transport,” annotated with genes encoding expansin (NtEXPA4) and lipid transfer protein (LTP)/LTP-like (NtLTP3 and NtEIG-C29), respectively. Al triggered the production of nitric oxide (NO) then reactive oxygen species (ROS). Addition of NO scavenger 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide decreased the levels of NO and a part of the transcriptional changes described above, but increased the levels of ROS and a loss of growth capacity, suggesting a role of the NO to induce the transcriptional changes partly and to repress these toxic responses under Al exposure. Under non-shaking (anaerobic) condition, the cells exhibited upregulation of several hypoxia-responsive genes. The cells exposed to Al exhibited the same level of Al accumulation but much lower levels of the Al responses including NO production, ROS production, a loss of growth capacity, citrate secretion, and a part of the transcriptional changes described above, compared with the cells under shaking condition. These results suggest that coexistence of oxygen with Al is necessary to trigger the Al responses related to toxicity and tolerance. No potential conflict of interest relevant to this article was reported.

Springer Netherlands Acta Medica Okayama 0236-5731 2015 Adsorption and removal of strontium in aqueous solution by synthetic hydroxyapatite EN Yuichi Nishiyama Tadashi Hanafusa Jun Yamashita Yoko Yamamoto Toshiro Ono Hydroxyapatite (HAP) is a main mineral constituent of bone and tooth and has an outstanding biocompatibility. HAP is a possible sorbent for heavy metals in wastewater due to its high adsorption capacity and low water solubility. We developed a removal system of 90Sr from aqueous solution by HAP column procedure. More than 90 % of 90Sr was adsorbed and removed from the 90Sr containing solution. Divalent cations, Ca2+, had little effect on the removal of 90Sr up to a concentration of 1 mmol L−1. This clearly indicates that the HAP column technique is advantageous with respect to the capacity to adsorb 90Sr from water present in the environment. No potential conflict of interest relevant to this article was reported.

岡山大学資源生物科学研究所 Acta Medica Okayama 0916-930X 2 2 1994 Effects of Aluminum on the Toxicity of Iron(II), Copper and Cadmium in Suspension-cultured Tobacco Cells 181 190 EN Yoko Yamamoto Yi-Chieh Chang Kanji Ono Hideaki Matsumoto The effects of aluminum (Al) on the cytotoxicity of ferrous iron (Fe(Ⅱ)), copper(Cu) and cadmium(Cd) were studied. Log-phase cells were treated with either FeSO4,CuSO4, or CdCl2 in the presence or absence of AlCl3(120μM) for 18h at pH 4.0. After the treatment, the viability was determined as relative growth of the metal-treated cells to the untreated control cells during the post-treated culture. A single treated with either Al, Fe(Ⅱ) or Cd did not inhibit the growth at the metal concerntrations up to 300 μM, 200 μM and 500 μM, respectively, whereas the growth was markedly inhibited at 15 μM Cu. Thus,the cells were relatively insensitive to Al, Fe(Ⅱ) and Cd and sensitive to Cu. When cells were treated with both Fe(Ⅱ)(120 μM)and Al(120μM), the growth was significantly inhibited and the cellular contents of both Al and Fe increased synergistically. After the treatment with Cu(0 to 10 μM) with or without Al, the cells grew more vigorously when they were treated in the presence of Al, althrouh the Cu content of the cells were not alterd by Al. The presence of Al during the treatmemt with Cd(0 to 2 μM) had no effect on the degree of growth inhibition by Cd. Thus, Al interacts with the toxicity of Fe(Ⅱ), Cu and Cd in different manners; synergistic with Fe(Ⅱ), antagonistic with Cu and apparently no effeco on Cd. No potential conflict of interest relevant to this article was reported.