Huang Wei-Lin, Yang Hui, Chen Xu-Feng, Lu Fei, Xie Rong-Rong, Yang Lin-Tong, Ye Xin, Huang Zeng-Rong, Chen Li-Song
College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
Plants (Basel). 2024 Dec 22;13(24):3584. doi: 10.3390/plants13243584.
Excessive copper (Cu) has become a common physiological disorder restricting the sustainable production of citrus. Coumarin (COU) is a hydroxycinnamic acid that can protect plants from heavy metal toxicity. No data to date are available on the ameliorative effect of COU on plant Cu toxicity. 'Xuegan' ( (L.) Osbeck) seedlings were treated for 24 weeks with nutrient solution containing two Cu levels (0.5 (Cu0.5) and 400 (Cu400) μM CuCl) × four COU levels (0 (COU0), 10 (COU10), 50 (COU50), and 100 (COU100) μM COU). There were eight treatments in total. COU supply alleviated Cu400-induced increase in Cu absorption and oxidative injury in roots and leaves, decrease in growth, nutrient uptake, and leaf pigment concentrations and CO assimilation (A), and photo-inhibitory impairment to the whole photosynthetic electron transport chain (PETC) in leaves, as revealed by chlorophyll fluorescence (OJIP) transient. Further analysis suggested that the COU-mediated improvement of nutrient status (decreased competition of Cu with Mg and Fe, increased uptake of nutrients, and elevated ability to maintain nutrient balance) and mitigation of oxidative damage (decreased formation of reactive oxygen species and efficient detoxification system in leaves and roots) might lower the damage of Cu400 to roots and leaves (chloroplast ultrastructure and PETC), thereby improving the leaf pigment levels, A, and growth of Cu400-treated seedlings.
过量的铜（Cu）已成为限制柑橘可持续生产的常见生理障碍。香豆素（COU）是一种羟基肉桂酸，可保护植物免受重金属毒性的影响。迄今为止，尚无关于COU对植物铜毒性改善作用的数据。用含有两种铜水平（0.5（Cu0.5）和400（Cu400）μM CuCl）×四种COU水平（0（COU0）、10（COU10）、50（COU50）和100（COU100）μM COU）的营养液对‘雪柑’（Citrus sinensis (L.) Osbeck）幼苗进行了24周的处理。总共有八种处理。香豆素的供应减轻了Cu400诱导的根系和叶片中铜吸收增加和氧化损伤，生长、养分吸收、叶片色素浓度和CO2同化（A）的降低，以及叶片中整个光合电子传递链（PETC）的光抑制损伤，这通过叶绿素荧光（OJIP）瞬变得以揭示。进一步分析表明，香豆素介导的营养状况改善（铜与镁和铁的竞争减少、养分吸收增加以及维持养分平衡的能力提高）和氧化损伤减轻（活性氧形成减少以及叶片和根系中有效的解毒系统）可能降低Cu400对根系和叶片（叶绿体超微结构和PETC）的损伤，从而提高Cu400处理幼苗的叶片色素水平、A和生长。
