The manuscript describes the first thorough exploration of gallium exposure in the model plant Arabidopsis. Gallium, a rare element, is one of the major elements in semiconductor compounds that are used in integrated circuits and optoelectronic devices. As one of major producers of semiconductor in the world, Hsinchu and Taichung Science Parks in Taiwan has been contaminated with gallium. The contamination of gallium in soil and water may lead to its uptake by plants and accumulation of gallium in the food chain. To our best knowledge, the harmful effects of gallium in plants are not yet investigated. Therefore, we investigated the accumulation, possible toxicity and defense systems of gallium exposure in plants. We found high similarities of exposure effects between gallium and aluminum. The Ga induced root secretion of citrate and malate play an important role for the protection from Ga toxicity.