Dopamine has demonstrated promise as a stress-relief substance. However, the function of dopamine in Cd tolerance and its mechanism remains largely unknown. The current study was performed to investigate the mechanism of dopamine on alleviating apple Cd stress through regular application of CdCl2 and dopamine solution to potting soil. The results indicated that dopamine significantly reduced reactive oxygen species (ROS) and Cd accumulation and alleviated the inhibitory effect of Cd stress on the growth of apple plants through activation of the antioxidant system, enhancement of photosynthetic capacity, and regulation of gene expression related to Cd absorption and detoxification. The richness of the rhizosphere microbial community increased, and community composition and assembly were affected by dopamine treatment. Network analysis of microbial communities showed that the numbers of nodes and total links increased significantly after dopamine treatment, while the keystone species shifted. Linear discriminant analysis effect size indicated that some biomarkers were significantly enriched after dopamine treatment, suggesting that dopamine induced plants to recruit potentially beneficial microorganisms (Pseudoxanthomonas, Aeromicrobium, Bradyrhizobium, Frankia, Saccharimonadales, Novosphingobium, and Streptomyces) to resist Cd stress. The co-occurrence network showed several metabolites that were positively correlated with relative growth rate and negatively correlated with Cd accumulation, suggesting that potentially beneficial microorganisms may be attracted by several metabolites (L-threonic acid, profenamine, juniperic acid and (3β,5ξ,9ξ)-3,6,19-trihydroxyurs-12-en-28-oic acid). Our results demonstrate that dopamine alleviates Cd stress in apple trees by recruiting beneficial microorganisms to enhance the physiological resilience revealed. This study provides an effective means to reduce the harm to agricultural production caused by heavy metals.

中文翻译：

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高通量测序和土壤代谢组学揭示，多巴胺通过招募有益微生物来增强生理恢复能力，从而减轻苹果树的镉胁迫


多巴胺已被证明是一种缓解压力的物质。然而，多巴胺在镉耐受中的作用及其机制仍知之甚少。本研究通过定期在盆栽土壤中施用 CdCl2 和多巴胺溶液来研究多巴胺缓解苹果镉胁迫的机制。结果表明，多巴胺通过激活抗氧化系统、增强光合能力、调控Cd相关基因表达，显着减少活性氧（ROS）和Cd积累，减轻Cd胁迫对苹果植株生长的抑制作用。吸收和解毒。根际微生物群落的丰富度增加，群落组成和组装受到多巴胺处理的影响。微生物群落网络分析表明，多巴胺处理后，节点数和总链接数显着增加，同时关键物种发生变化。线性判别分析效应大小表明，一些生物标志物在多巴胺处理后显着富集，这表明多巴胺诱导植物招募潜在有益的微生物（假黄单胞菌属、气微菌属、慢生根瘤菌属、弗兰克氏菌属、糖单胞菌属、新鞘氨醇菌属和链霉菌属）来抵抗镉胁迫。共现网络显示几种代谢物与相对生长速率呈正相关，与 Cd 积累呈负相关，这表明潜在有益的微生物可能会被几种代谢物（L-苏糖酸、洛芬纳明、杜松酸和 (3β,5Ψ, 9xi)-3,6,19-三羟基-12-en-28-油酸)。 我们的结果表明，多巴胺通过招募有益微生物来增强生理恢复能力，从而减轻苹果树的镉胁迫。该研究为减少重金属对农业生产的危害提供了有效手段。