More effective than direct contact: Nano hydroxyapatite pre-treatment regulates the growth and Cd uptake of rice (Oryza sativa L.) seedlings

• Published in: Journal of hazardous materials 2024-02, Vol.463, p.132889-132889, Article 132889
• Main Authors: Wu, Hanxin, Tong, Jianhao, Jiang, Xiaohan, Wang, Jing, Zhang, Haonan, Luo, Yating, Pang, Jingli, Shi, Jiyan
• Format: Article
• Language: English
• Subjects: Cadmium - metabolism; Gibberellins - analysis; Gibberellins - metabolism; Gibberellins - pharmacology; Oryza; Plant Roots - metabolism; Proteomics; Seedlings; Soil Pollutants - metabolism
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2023.132889

Cd contamination in rice urgently needs to be addressed. Nano hydroxyapatite (n-HAP) is an eco-friendly material with excellent Cd fixation ability. However, due to its own high reactivity, innovative application of n-HAP in the treatment of Cd contamination in rice is needed. In this study, we proposed a new application, namely n-HAP pre-treatment, which can effectively reduce Cd accumulation in rice and alleviate Cd stress. The results showed that 80 mg/L n-HAP pre-treatment significantly reduced Cd content in rice shoot by 35.1%. Biochemical and combined transcriptomic-proteomic analysis revealed the possible molecular mechanisms by which n-HAP pre-treatment promoted rice growth and reduced Cd accumulation. (1) n-HAP pre-treatment regulated gibberellin and jasmonic acid synthesis-related pathways, increased gibberellin content and decreased jasmonic acid content in rice root, which promoted rice growth; (2) n-HAP pre-treatment up-regulated gene CATA1 expression and down-regulated gene OsGpx1 expression, which increased rice CAT activity and GSH content; (3) n-HAP pre-treatment up-regulated gene OsZIP1 expression and down-regulated gene OsNramp1 expression, which reduced Cd uptake, increased Cd efflux from rice root cells.