Huang Wei-Lin, Huang Wei-Tao, Chen Xu-Feng, Wu Ti, Tong Liang-Yuan, Xia Tian-Tian, Wu Bi-Sha, Lu Fei, Lai Ning-Wei, Yang Lin-Tong, Chen Li-Song
College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.
College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou, 350002, China; Fujian Provincial Key Laboratory of Ecology-Toxicological Effects & Control for Emerging Contaminants/Key Laboratory of Ecological Environment and Information Atlas, College of Environmental and Biological Engineering, Putian University, Putian, 351100, China.
Plant Physiol Biochem. 2025 Jul;224:109949. doi: 10.1016/j.plaphy.2025.109949. Epub 2025 Apr 29.
Most citrus trees are planted in acidic soil with high availability of copper (Cu). Little is known about the mechanisms by which coumarin (COU) reduces Cu excess in plants. 'Xuegan' (Citrus sinensis) seedlings were treated with 0.5 (Cu0.5) or 400 (Cu excess or Cu400) CuCl and 0 (COU0) or 100 (COU100) μM COU for 24 weeks. COU100 alleviated Cu400-induced alterations in gene expression and metabolite profiles, cell wall (CW) materials (CWMs), CW components (CWCs), and Fourier transform infrared (FTIR) spectra of CWMs in roots; increase in Cu concentration in roots, root CWMs (RCWMs), root CWCs (RCWCs), Cu and Ca fractions in RCWMs, and Cu fraction in CW pectin; and decrease in Ca concentrations in roots, RCWMs, and RCWCs. In addition, COU100 mitigated Cu400-induced increase in electrolyte leakage and concentrations of total coumarins, total phenolics, total falvonoids, and nonstructural carbohydrates (NCs) and decrease in total free amino acid concentration in roots, as well as impairment in root system architecture (RSA) and root growth. Our results corroborated the hypothesis that the alleviation of root Cu excess by COU was caused by the combination of following several aspects: (a) reduced impairment to root growth and RSA; (b) upregulated ability to maintain CW and plasma membrane stability and function by maintaining Cu and calcium homeostasis; (c) elevated adaptability of primary metabolism to Cu excess; and (d) upregulated biosynthesis and catabolism (turnover) of secondary metabolites (SMs) and less upregulation of SMs. COU0-treated roots underwent some physiological and molecular adaptations to Cu excess.
大多数柑橘树种植在铜（Cu）有效性高的酸性土壤中。关于香豆素（COU）降低植物体内过量铜的机制，人们了解甚少。用0.5（Cu0.5）或400（过量铜或Cu400）μM的CuCl以及0（COU0）或100（COU100）μM的COU处理‘雪柑’（甜橙）幼苗24周。COU100减轻了Cu400诱导的根中基因表达、代谢物谱、细胞壁（CW）物质（CWM）、CW成分（CWC）以及CWM的傅里叶变换红外（FTIR）光谱的变化；根中铜浓度、根CWM（RCWM）、根CWC（RCWC）、RCWM中铜和钙组分以及CW果胶中铜组分的增加；以及根、RCWM和RCWC中钙浓度的降低。此外，COU100减轻了Cu400诱导的根中电解质渗漏增加以及总香豆素、总酚类、总黄酮类和非结构性碳水化合物（NC）浓度的增加，以及总游离氨基酸浓度的降低，还有根系结构（RSA）和根生长的受损。我们的结果证实了以下假设：COU减轻根中过量铜是由以下几个方面共同作用导致的：（a）减轻对根生长和RSA的损害；（b）通过维持铜和钙稳态上调维持CW和质膜稳定性及功能的能力；（c）提高初级代谢对过量铜的适应性；（d）上调次生代谢物（SM）的生物合成和分解代谢（周转），且对SM的上调较少。用COU0处理的根对过量铜进行了一些生理和分子适应。
