Xie Qin, Xu Wenting, Wang Qing, Yao Feihong, Jiang Yachao, Cao Haijia, Lin Wanhuang
College of Pharmacy, Xiangnan University, Chenzhou 423099, China.
Hunan Provincial Key Laboratory of Phytohormones and Growth Development, Hunan Agricultural University, Changsha 410128, China.
Plants (Basel). 2025 May 8;14(10):1405. doi: 10.3390/plants14101405.
Cadmium (Cd) is an extremely toxic heavy metal that can move from the soil to plants and enter the human body via the food chain, causing severe health issues for humans. Phytoremediation uses hyperaccumulators to extract heavy metals from polluted soil. Phytohormones, wildly used plant growth regulators, have been explored to improve phytoremediation efficiency. Abscisic acid (ABA) is also an essential regulator of plant tolerance to biotic and abiotic stresses, including heavy metal-induced toxicity. Previous research has revealed that Roxb. () has a strong ability to enrich Cd and can be used as a Cd hyperaccumulator. In this study, physiological and biochemical analysis revealed that under Cd stress, exogenous ABA application alleviated oxidative stress, increased the Cd concentration in , especially in the roots, and changed the phytohormone concentration in . Transcriptome analysis was conducted to explore the molecular mechanisms by which ABA regulates Cd uptake and accumulation in , and to further understand the regulatory role of ABA. The results show that ABA treatment affected gene expression in roots under Cd stress. This study identified 5788 differentially expressed genes (DEGs) (2541 up-regulated and 3247 down-regulated). Moreover, 96 metal transport-related DEGs, 54 phytohormone-related DEGs, 89 cell wall-related DEGs, 113 metal chelation-related DEGs, and 102 defense system-related DEGs cooperated more closely under exogenous ABA application to regulate Cd uptake and accumulation in under Cd stress. These results may help to elucidate the mechanisms by which ABA regulates Cd uptake and accumulation in plants, and provide a reference for developing a phytohormone-based strengthening strategy to improve the phytoremediation ability of other hyperaccumulators or accumulator species. The key genes involved in ABA's regulation of Cd uptake and accumulation in need to be further analyzed and functionally verified. This may expand our understanding of the molecular regulatory mechanisms underlying heavy metal uptake and accumulation in hyperaccumulators.
镉（Cd）是一种剧毒重金属，它可从土壤转移至植物，并通过食物链进入人体，给人类带来严重健康问题。植物修复利用超富集植物从污染土壤中提取重金属。植物激素作为广泛使用的植物生长调节剂，已被用于提高植物修复效率。脱落酸（ABA）也是植物对生物和非生物胁迫（包括重金属诱导的毒性）耐受性的重要调节因子。先前的研究表明，罗勒（Ocimum basilicum L.）具有很强的镉富集能力，可作为镉超富集植物。在本研究中，生理生化分析表明，在镉胁迫下，外源施加ABA可缓解氧化应激，提高罗勒中的镉浓度，尤其是根部，并改变罗勒中的植物激素浓度。进行转录组分析以探究ABA调节罗勒中镉吸收和积累的分子机制，并进一步了解ABA 的调节作用。结果表明，ABA处理影响了镉胁迫下罗勒根部的基因表达。本研究共鉴定出5788个差异表达基因（DEGs）（2541个上调基因和3247个下调基因）。此外，96个与金属转运相关的DEGs、54个与植物激素相关的DEGs、89个与细胞壁相关的DEGs、113个与金属螯合相关的DEGs和102个与防御系统相关的DEGs在外源ABA处理下协同作用更紧密，以调节镉胁迫下罗勒中镉的吸收和积累。这些结果可能有助于阐明ABA调节植物中镉吸收和积累的机制，并为制定基于植物激素的强化策略以提高其他超富集植物或富集植物物种的植物修复能力提供参考。参与ABA调节罗勒中镉吸收和积累的关键基因有待进一步分析和功能验证。这可能会扩展我们对超富集植物中重金属吸收和积累的分子调控机制的理解。
