Wen Yu-Han, Chen Xi, Sun Ming, Yang Chao-Hui, Xu Meng-Yuan, Lai Feng-Xiang, Fu Si-Qi, Fan Yu-Meng, Guo Xin-Peng, Li Qun, Wu Guo
College of Life Science, Sichuan Normal University, Chengdu 610101, China.
College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China.
Plants (Basel). 2025 Jun 12;14(12):1802. doi: 10.3390/plants14121802.
The present study systematically investigated the cesium (Cs) enrichment characteristics and physiological responses to Cs exposure in radish ( L.) seedlings under hydroponic conditions through integrated physiological, biochemical, and transcriptome analyses. The results showed that the Cs content in radish roots, stems, and cotyledons increased progressively with rising Cs concentrations (0.25-2 mM), and Cs mainly accumulated in the cotyledon. The transfer factor (TF) increased by 63.29% (TF = 3.87) as the Cs concentration increased from 0.25 to 2 mM, while the biological concentration factor (BCF) decreased by 72.56% (BCF = 14.87). Severe growth inhibition was observed at 2 mM Cs stress, with biomass reduction reaching 29.73%. The carotenoid content decreased by 11.92%; however, the total chlorophyll content did not change significantly, and the photosynthesis of radish was not affected. In addition, Cs exposure disrupted mineral nutrient homeostasis, decreasing potassium (K), sodium (Na), magnesium (Mg), and iron (Fe) content. The superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) activities, reactive oxygen species (ROS), and malondialdehyde (MDA) content increased under the different Cs treatments, which indicated that Cs exposure induced oxidative stress response in radish seedlings. Transcriptome analysis detected a total of 4326 differentially expressed genes (DEGs), in which altered expression patterns in genes associated with mineral transport, antioxidant systems, and carotenoid biosynthesis pathways in radish under 2 mM Cs treatment were observed. In conclusion, this study comprehensively investigated the physiological and molecular responses of radish to Cs stress, revealing that Cs accumulation exhibited site-specific preference and concentration dependence and induced physiological disturbances, including growth inhibition and photosynthetic pigment metabolism alterations. At the transcription level, Cs activated the enzymatic antioxidant system, related genes, and stress-response pathways. Notably, this study is the first to demonstrate that Cs disrupts plant mineral nutrition homeostasis and inhibits carotenoid biosynthesis. These findings establish a crucial theoretical foundation for utilizing radish in Cs-contaminated phytoremediation strategies.
本研究通过综合生理、生化和转录组分析，系统地研究了水培条件下萝卜（L.）幼苗对铯（Cs）的富集特性及对Cs暴露的生理响应。结果表明，随着Cs浓度（0.25 - 2 mM）升高，萝卜根、茎和子叶中的Cs含量逐渐增加，且Cs主要积累在子叶中。当Cs浓度从0.25 mM增加到2 mM时，转移因子（TF）增加了63.29%（TF = 3.87），而生物富集系数（BCF）下降了72.56%（BCF = 14.87）。在2 mM Cs胁迫下观察到严重的生长抑制，生物量减少达29.73%。类胡萝卜素含量下降了11.92%；然而，总叶绿素含量没有显著变化，萝卜的光合作用未受影响。此外，Cs暴露破坏了矿质营养稳态，降低了钾（K）、钠（Na）、镁（Mg）和铁（Fe）的含量。在不同的Cs处理下，超氧化物歧化酶（SOD）、过氧化物酶（POD）和过氧化氢酶（CAT）活性、活性氧（ROS）和丙二醛（MDA）含量增加，这表明Cs暴露诱导了萝卜幼苗的氧化应激反应。转录组分析共检测到4326个差异表达基因（DEGs），其中观察到在2 mM Cs处理下萝卜中与矿质运输、抗氧化系统和类胡萝卜素生物合成途径相关的基因表达模式发生改变。总之，本研究全面调查了萝卜对Cs胁迫的生理和分子响应，揭示了Cs积累表现出部位特异性偏好和浓度依赖性，并诱导了包括生长抑制和光合色素代谢改变在内的生理紊乱。在转录水平上，Cs激活了酶促抗氧化系统、相关基因和应激反应途径。值得注意的是，本研究首次证明Cs破坏了植物矿质营养稳态并抑制了类胡萝卜素生物合成。这些发现为利用萝卜进行Cs污染植物修复策略奠定了关键的理论基础。
