Pan Jiao, Xu Guofeng, Liang Minglin, Mo Huiting, Luo Dengjie, Wang Caijin, Ullah Rehmat, Li Yun, Liao Changjun, Wei Xiqin, Chen Peng
Guangxi Key Laboratory of Agro-environment and Agric-products safety, Key Laboratory of Plant Genetics and Breeding, College of Agriculture, Guangxi University, Nanning, 530004, PR China.
Guangxi Bossco Environmental Protection Technology Co., Ltd, Nanning, 530004, PR China.
Plant Physiol Biochem. 2025 Aug 5;229(Pt A):110312. doi: 10.1016/j.plaphy.2025.110312.
Heavy-metal (HM) contamination in agricultural soils poses significant risks to ecosystems and human health. Eco-friendly solutions such as biochar application and phytoremediation have emerged as promising approaches for HM immobilization. Industrial hemp (Cannabis sativa L.), a fast-growing fiber crop with high biomass yield and strong HM stress tolerance, demonstrates significant potential for phytoremediation. In the present study, kenaf biochar (KBC) demonstrated multi-layer chemisorption behavior within a ternary HM system, exhibiting high affinity for HMs, especially for Cd and Zn. A controlled pot experiment was performed to examine the effectiveness of KBC in reducing the solubility of HMs and limiting their uptake by industrial hemp. The results showed that KBC amendment enhanced soil physicochemical properties, significantly promoting hemp growth and increasing biomass yield. Moreover, KBC enhanced photosynthetic efficiency through upregulation of PetH, LHCB7, and photosynthesis-related genes. Transcriptome analysis revealed the KBC mediated the cascade regulation of MAPK and CDPK signaling pathways, as well as plant hormone signaling pathways, thereby promoting the activation of antioxidant enzyme systems to resist HMs stress. KBC also regulated the genes associated with antioxidant enzyme systems, including superoxide dismutase (SOD) genes and non-enzymatic glutathione-ascorbate (AsA-GSH) cycle, reducing malondialdehyde (MDA) content and reactive oxygen species (ROS) accumulation to restore redox homeostasis. Meanwhile, KBC reduced HM bioavailability in soil, thereby limiting their translocation to plant tissues. It also maintained ion homeostasis by modulating key transporters (ZIP, COPT) and CDPK. This study elucidates the physiological and molecular mechanisms underlying KBC-mediated HM tolerance in industrial hemp, providing valuable insights for sustainable phytoremediation of mining-degraded soils.
农业土壤中的重金属（HM）污染对生态系统和人类健康构成重大风险。生物炭应用和植物修复等环保解决方案已成为固定重金属的有前景的方法。工业大麻（Cannabis sativa L.）是一种生长迅速、生物量产量高且对重金属胁迫耐受性强的纤维作物，在植物修复方面具有巨大潜力。在本研究中，红麻生物炭（KBC）在三元重金属体系中表现出多层化学吸附行为，对重金属具有高亲和力，尤其是对镉和锌。进行了一项对照盆栽试验，以检验KBC在降低重金属溶解度和限制工业大麻对其吸收方面的有效性。结果表明，添加KBC改善了土壤理化性质，显著促进了大麻生长并提高了生物量产量。此外，KBC通过上调PetH、LHCB7和光合作用相关基因提高了光合效率。转录组分析表明，KBC介导了丝裂原活化蛋白激酶（MAPK）和钙依赖蛋白激酶（CDPK）信号通路以及植物激素信号通路的级联调控，从而促进抗氧化酶系统的激活以抵抗重金属胁迫。KBC还调节了与抗氧化酶系统相关的基因，包括超氧化物歧化酶（SOD）基因和非酶促谷胱甘肽 - 抗坏血酸（AsA - GSH）循环，降低了丙二醛（MDA）含量和活性氧（ROS）积累，以恢复氧化还原稳态。同时，KBC降低了土壤中重金属的生物有效性，从而限制了它们向植物组织的转运。它还通过调节关键转运蛋白（ZIP、COPT）和CDPK维持离子稳态。本研究阐明了KBC介导工业大麻对重金属耐受性的生理和分子机制，为采矿退化土壤的可持续植物修复提供了有价值的见解。
