Gallium (Ga) is an emerging chemical pollutant chiefly associated with high-tech industries. Boron (B) alleviates the negative effects of toxic elements on plant growth. Thereby, the effects of B fertilization on Ga toxicity in rice seedlings was studied to clarify the role of iron plaque in the distribution of Ga, Fe, and B in Ga-treated rice seedlings in the presence or absence of B. Gallium exposure significantly reduced the biomass of rice seedlings. Boron deficiency induced a significant change in the distribution of B in Ga-treated rice seedlings compared with “Ga+B” treatments. Accumulation of Ga in roots, dithionite-citrate-bicarbonate (DCB) extracts, and shoots showed a dose-dependent manner from both +B and –B rice seedlings. Boron nutrition levels affect the distribution of Fe in roots, DCB extracts, and shoots, in which DCB-extractable Fe was significantly decreased from “Ga-B” treatments compared with “Ga+B” treatments. Root activity was significantly decreased in both Ga-exposed rice seedlings; however, B-deficient seedlings showed a severe reduction than +B rice seedlings. These results reveal that Fe plaque might be a temporary sink for B accumulation when plants are grown with proper B, wherein the re-utilization of DCB-extractable B stored in Fe plaque is mandatory for plant growth under B deficiency. Correlation analysis revealed that B deficiency decreased the root activity of Ga-exposed rice seedlings by reducing DCB-extractable Fe and increasing DCB-extractable Ga in Fe plaque. This study enhances our understanding of how B nutritional levels affect Ga toxicity in rice plants.

镓（Ga）是一种主要与高科技产业相关的新兴化学污染物。硼 (B) 减轻有毒元素对植物生长的负面影响。因此，研究了B施肥对水稻幼苗Ga毒性的影响，以阐明铁斑在存在或不存在B的情况下，在Ga处理的水稻幼苗中Ga、Fe和B分布中的作用。镓暴露显着减少水稻秧苗的生物量。与“Ga+B”处理相比，缺硼导致Ga处理水稻幼苗中B的分布发生显着变化。+B 和 –B 稻苗根部、连二亚硫酸盐-柠檬酸盐-碳酸氢盐 (DCB) 提取物和芽中 Ga 的积累均显示出剂量依赖性。硼营养水平影响铁在根、DCB提取物和地上部的分布，其中“Ga-B”处理与“Ga+B”处理相比，DCB可提取的Fe显着降低。暴露于 Ga 的水稻幼苗的根系活力均显着降低；然而，B-缺陷秧苗表现出比+B水稻秧苗严重减少。这些结果表明，当植物在含有适当硼的情况下生长时，铁斑可能是硼积累的临时汇，其中储存在铁斑中的 DCB 可提取硼的再利用对于硼缺乏下的植物生长是强制性的。相关分析表明，B 缺乏通过减少 DCB 可提取的 Fe 和增加 Fe 斑块中 DCB 可提取的 Ga 来降低暴露 Ga 的水稻幼苗的根系活力。这项研究增强了我们对 B 营养水平如何影响水稻植株中 Ga 毒性的理解。