In the present study, a set of pot culture experiments was conducted to reveal how the metabolism process of phenolic compounds was affected by cadmium (Cd) and zinc (Zn) and to further uncover heavy metal tolerance mechanisms in Kandelia obovata. After 60d of treatment, the biomass and chlorophyll a content in the leaves were suppressed, but total phenolic compounds in roots and leaves were improved by the increasing gradient of Cd or Zn concentrations; Total phenolic compounds significantly increased by 3.6–44.6% in the roots, and by 0.4–126.6% in the leaves. At the meantime, the activity of Shikimate dehydrogenase (SKDH), cinnamyl alcohol dehydrogenase (CAD), and polyphenol oxidase (PPO) in the roots increased by 11.2–307.6%, 12.4–175.4% and − 2.7–392.8%, and the results were 3.4–69.5%, 1.7–40.0%, 16.0–99.7% in the leaves. Higher toxicity of Cd than Zn, as well as slight alleviating effect of 100 mg kg⁻¹ Zn on 2.5 mg kg⁻¹ Cd were found. Additionally, a significantly positive correlation coefficients for relationship between phenolic metabolism related enzyme activity and Cd/Zn contamination levels was found, and leaf SKDH, leaf CAD, and leaf PPO activities were moderately correlated with leaf Cd (r = 0.39, r = 0.43, and r = 0.57, respectively) and leaf Zn (r = 0.44, r = 0.41, r = 0.19, respectively) content, which indicate that Cd and Zn play a previously unrecognized but major role in phenolic compounds synthesis, transport, and metabolism in K. obovata. The results also provided evidence that the application of high levels of Cd and Zn was accompanied by three phenolic metabolism pathways participating in heavy metal tolerance process.

在本研究中，进行了一系列盆栽实验，以揭示酚类化合物的代谢过程如何受镉（Cd）和锌（Zn）的影响，并进一步揭示卵形金盏花对重金属的耐受机制。处理60d后，生物量和叶绿素a镉和锌浓度梯度的增加可抑制叶片中的含量，但根和叶片中的总酚类化合物得到改善。根中的总酚类化合物显着增加，叶中的总酚含量显着增加3.6–44.6％，叶中的总酚含量显着增加0.4–126.6％。同时，根部的Shikimate脱氢酶（SKDH），肉桂醇脱氢酶（CAD）和多酚氧化酶（PPO）的活性分别增加了11.2–307.6％，12.4–175.4％和− 2.7–392.8％。叶片中分别为3.4–69.5％，1.7–40.0％，16.0–99.7％。Cd的毒性比Zn高，并且100 mg kg ^-1 Zn对2.5 mg kg ^-1的缓解作用较小发现了镉。此外，还发现酚代谢相关酶活性与Cd / Zn污染水平之间存在显着的正相关系数，叶片SKDH，叶片CAD和叶片PPO活性与叶片Cd呈中度相关（r = 0.39，r = 0.43，和r分别为0.57和Zn的含量（分别为r = 0.44，r = 0.41和r = 0.19），这表明Cd和Zn以前在酚类化合物的合成，运输和代谢中起着未被认识的重要作用。K. obovata。结果也提供了证据，表明高水平的镉和锌的施用伴随着三个参与重金属耐受性过程的酚类代谢途径。