Heavy metal stress threatens plant growth and productivity. In this study, we investigated the effects of CuSO4 and ZnSO4 toxicity on sorghum seedlings, focusing on their impact on biomass, germination rates, growth parameters, antioxidant enzyme activities, gene expression profiles, and stress resistance mechanisms. As a result, eight sorghum superoxide dismutase (SOD) genes were identified, and their evolutionary relationships with cis-acting regulatory elements and their expressional patterns were evaluated. Integrating transcriptomic data revealed a key SOD member SbCSD1 that might contribute to plant abiotic stress resistance. Furthermore, SbCSD1 overexpression enhanced plant tolerance to CuSO4 and ZnSO4 stress by regulating SOD activity and interacting with copper chaperone for superoxide dismutase 1 (CCS1) in the plant nucleus and cytoplasm. Meanwhile, silencing CCS1 in SbCSD1-overexpressing plants revealed that SbCSD1 and CCS1 synergistically contribute to Cu stress tolerance. By integrating transcriptomic and genetic data, herein we provide novel insights into the orchestration of plant responses to heavy-metal stress in sorghum by SOD.

中文翻译：

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超氧化物歧化酶通过与超氧化物歧化酶的 Cu 伴侣相互作用，正向调节高粱双色 Cu/Zn 的毒性耐受性


重金属胁迫威胁着植物的生长和生产力。本研究研究了 CuSO4 和 ZnSO4 对高粱幼苗的毒性，重点研究了它们对生物量、发芽率、生长参数、抗氧化酶活性、基因表达谱和抗逆机制的影响。结果，鉴定出 8 个高粱超氧化物歧化酶 （SOD） 基因，并评价它们与顺式作用调节元件的进化关系及其表达模式。整合转录组数据揭示了一个关键的 SOD 成员 SbCSD1，它可能有助于植物的非生物胁迫抗性。此外，SbCSD1 过表达通过调节 SOD 活性并与植物细胞核和细胞质中超氧化物歧化酶 1 （CCS1） 的铜伴侣相互作用，增强了植物对 CuSO4 和 ZnSO4 胁迫的耐受性。同时，在 SbCSD1 过表达植物中沉默 CCS1 表明 SbCSD1 和 CCS1 协同促进 Cu 胁迫耐受性。通过整合转录组学和遗传学数据，我们在这里为 SOD 对植物对高粱中重金属胁迫的反应提供了新的见解。