possesses the capacity to tolerate and accumulate various heavy metals. The cell wall is the first barrier to inhibit heavy metals into the plant cytoplasm. In this work, we investigated the effects of cadmium (Cd) exposure on lignin and pectin synthesis in roots by integrated metabolomic and transcriptomic analyses. The findings showed that the contents of lignin and pectin, the activities of phenylalanine ammonia-lyase, laccase, superoxide dismutase, and peroxidase significantly increased following Cd stress, while the activity of pectinesterase decreased. Transcriptome analysis revealed 94 (20 upregulated and 74 downregulated) and 10 (7 upregulated and 3 downregulated) differentially expressed genes in the phenylpropane metabolic pathway and galactose metabolic pathway, respectively. Additionally, metabolomic analyses revealed differentially expressed metabolites related to lignin and pectin synthesis, including N-acetyl-D-phenylalanine, sinapyl alcohol, eugenol, galactosylglycerol, 2-keto-3-deoxy-D-gluconic acid, sucrose, and lactose 6-phosphate, implying lignin and pectin in cell wall play vital roles in Cd detoxification. Our results offer a molecular-scale perspective for further exploring the adaptability in Cd-exposed plants.

中文翻译：

---

代谢组学和转录组学分析表明，芥菜通过增强根中果胶和木质素的合成来响应镉胁迫


具有耐受和积累多种重金属的能力。细胞壁是抑制重金属进入植物细胞质的第一道屏障。在这项工作中，我们通过综合代谢组学和转录组学分析研究了镉（Cd）暴露对根部木质素和果胶合成的影响。结果表明，Cd胁迫后木质素和果胶含量、苯丙氨酸解氨酶、漆酶、超氧化物歧化酶和过氧化物酶活性显着升高，而果胶酯酶活性降低。转录组分析显示苯丙烷代谢途径和半乳糖代谢途径中分别有 94 个（20 个上调和 74 个下调）和 10 个（7 个上调和 3 个下调）差异表达基因。此外，代谢组学分析揭示了与木质素和果胶合成相关的差异表达代谢物，包括 N-乙酰基-D-苯丙氨酸、芥子醇、丁子香酚、半乳糖基甘油、2-酮-3-脱氧-D-葡萄糖酸、蔗糖和乳糖 6-磷酸盐，表明细胞壁中的木质素和果胶在镉解毒中发挥重要作用。我们的结果为进一步探索镉暴露植物的适应性提供了分子尺度的视角。