The combined effects of copper and zinc on Arabidopsis involve differential regulation of chlorophyll synthesis and photosystem function

Copper (Cu) and zinc (Zn) are both oxidation-reducing metal elements that are necessary for plant growth, and their effect often depends on their concentration. However, there are few studies that have investigated how plants are stressed and affected when the two ions are present simultaneously, especially when one ion is beneficial due to a low concentration and the other is detrimental due to a high concentration. To address this question, we treated Arabidopsis plants with either high or/and low concentrations of the two ions and investigated their mutual effects and the underlying molecular mechanism, focusing on photosynthetic function. The results showed that the photosynthetic pigment content and the performance of photosynthetic systems were most affected when both metal ions were present at detrimental concentrations (60 μM Cu for Cu