Division of Agricultural Chemistry, Taiwan Agricultural Research Institute, No.189, Zhongzheng Rd., Wufeng Dist., Taichung 41362, Taiwan.
Department of Agricultural Chemistry, National Taiwan University, No. 1, Sec. 4, Roosevelt Rd., Taipei 10617, Taiwan.
Ecotoxicol Environ Saf. 2017 Jan;135:32-39. doi: 10.1016/j.ecoenv.2016.09.016. Epub 2016 Sep 24.
Limited information is available on the effects of gallium (Ga) and indium (In) on the growth of paddy rice. The Ga and In are emerging contaminants and widely used in high-tech industries nowadays. Understanding the toxicity and accumulation of Ga and In by rice plants is important for reducing the effect on rice production and exposure risk to human by rice consumption. Therefore, this study investigates the effect of Ga and In on the growth of rice seedlings and examines the accumulation and distribution of those elements in plant tissues. Hydroponic cultures were conducted in phytotron glasshouse with controlled temperature and relative humidity conditions, and the rice seedlings were treated with different levels of Ga and In in the nutrient solutions. The growth index and the concentrations of Ga and In in roots and shoots of rice seedlings were measured after harvesting. A significant increase in growth index with increasing Ga concentrations in culture solutions (<10mgGaL) was observed. In addition, the uptake of N, K, Mg, Ca, Mn by rice plants was also enhanced by Ga. However, the growth inhibition were observed while the In concentrations higher than 0.08mgL, and the nutrients accumulated in rice plants were also significant decreased after In treatments. Based on the dose-response curve, we observed that the EC (effective concentration resulting in 10% growth inhibition) value for In treatment was 0.17mgL. The results of plant analysis indicated that the roots were the dominant sink of Ga and In in rice seedlings, and it was also found that the capability of translocation of Ga from roots to shoots were higher than In. In addition, it was also found that the PT (threshold concentration of phytotoxicity resulting in 10% growth retardation) values based on shoot height and total biomass for In were 15.4 and 10.6μgplant, respectively. The beneficial effects on the plant growth of rice seedlings were found by the addition of Ga in culture solutions. In contrast, the In treatments led to growth inhibition of rice seedlings. There were differences in the phytotoxicity, uptake, and translocation of the two emerging contaminants in rice seedlings.
关于镓（Ga）和铟（In）对水稻生长的影响，相关信息有限。目前，Ga 和 In 是新兴的污染物，被广泛应用于高科技产业。了解水稻对 Ga 和 In 的毒性和积累作用，对于减少其对水稻生产的影响以及降低通过食用水稻而摄入这些污染物的风险非常重要。因此，本研究调查了 Ga 和 In 对水稻幼苗生长的影响，并检测了这些元素在植物组织中的积累和分布情况。在温室玻璃房中进行了水培实验，以控制温度和相对湿度条件，同时在营养液中用不同浓度的 Ga 和 In 处理水稻幼苗。收获后，测量了水稻幼苗的生长指数以及根和茎中的 Ga 和 In 浓度。在培养液中 Ga 浓度低于 10mgGaL 时，观察到生长指数随着 Ga 浓度的增加而显著增加。此外，Ga 还增强了水稻对氮（N）、钾（K）、镁（Mg）、钙（Ca）、锰（Mn）的吸收。然而，当 In 浓度高于 0.08mgL 时，观察到生长受到抑制，并且在经过 In 处理后，植物中积累的营养物质也显著减少。根据剂量-反应曲线，我们观察到 In 处理的 EC（有效浓度，导致 10%生长抑制）值为 0.17mgL。植物分析结果表明，根是水稻幼苗中 Ga 和 In 的主要吸收器官，还发现 Ga 从根向茎的转运能力高于 In。此外，还发现基于茎高和总生物量的 In 对植物毒性的 PT（导致 10%生长迟缓的阈值浓度）值分别为 15.4μgplant 和 10.6μgplant。在营养液中添加 Ga 对水稻幼苗的生长有促进作用，而 In 处理则导致水稻幼苗的生长受到抑制。这两种新兴污染物在水稻幼苗中的植物毒性、吸收和转运存在差异。
