Copper (Cu) is an essential metal and both its deficiency and excess has negative effects on the growth and physiology of plants. Some plant species can tolerate high Cu concentrations due to their anatomical and physiological strategies. These plants can avoid absorption or accumulate this element in their biomass. Thus, the aim was to analyze the anatomical and physiological changes of Alternanthera tenella in response to excess Cu under in vitro conditions. A. tenella plants, previously established in vitro, were transferred to culture media containing 0, 25, 50, 100 or 200 µM Cu. At 30 days of culture, the stem and leaf anatomy, contents of photosynthetic pigments mineral nutrients, chlorophyll fluorescence, and, growth were analyzed. The excess Cu induced lower biomass accumulation. Plants also presented a decline in cell sizes of stem and leaf tissues under high Cu concentrations. Greater formation of druse crystals and lower number of active reaction centers (RC/CS_M) were observed with 200 μM Cu. The Cu treatments modulated the contents of mineral nutrients and photosynthetic pigments of the plants. Plants cultured in media with Cu absence or excess (200 μM Cu) presented partial inhibition of electron transport and photochemical activity of photosystem II. Even though A. tenella plants showed clear signs of stress under Cu excess, they also have a strong capacity for Cu bioaccumulation and tolerance. A. tenella plants can be used for phytoremediation or bioindication due to their tolerance and high Cu bioaccumulation capacity.

铜（Cu）是必不可少的金属，其缺乏和过量都对植物的生长和生理产生不利影响。一些植物由于其解剖学和生理学策略可以耐受高浓度的铜。这些植物可以避免吸收或在生物质中积累这种元素。因此，目的是分析在体外条件下响应过量铜对中华绒螯蟹的解剖和生理变化。A.tenella将先前在体外建立的植物转移到含有0、25、50、100或200 µM Cu的培养基中。培养30天后，分析了茎和叶的解剖结构，光合色素矿物质养分的含量，叶绿素荧光以及生长。过量的铜诱导较低的生物量积累。在高铜浓度下，植物的茎和叶组织的细胞大小也减少了。用200μM的铜观察到更多的沉孔晶体形成和更少的活性反应中心（RC / CS _M）。铜处理调节了植物的矿物质营养和光合色素的含量。在不含或不含铜（200μM铜）的培养基中培养的植物部分抑制了电子传输和光系统II的光化学活性。即使A. tenella植物在Cu过量时表现出明显的胁迫迹象，它们还具有强大的Cu生物积累能力和耐受性。由于其耐受性和高的铜生物积累能力，A。tenella植物可用于植物修复或生物指示。