Journal of Hazardous Materials 458 (2023) 131931 Available online 25 June 2023 0304-3894/© 2023 Elsevier B.V. All rights reserved. Research Paper Multiple insights into lignin-mediated cadmium detoxifcation in rice (Oryza sativa) Qin Dong a, 1 , Yingjie Wu a, *, 1 , Bing Li a , Xi Chen a , Lu Peng a , Zulfqar Ali Sahito b , Huanxiu Li c , Yulan Chen d , Qi Tao a , Qiang Xu a , Rong Huang a , Youlin Luo a , Xiaoyan Tang a , Qiquan Li a , Changquan Wang a, * a College of Resources, Sichuan Agricultural University, Chengdu 611130, China b Key Laboratory of Environment Remediation and Ecological Health of Ministry of Education, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China c College of Horticulture, Sichuan Agricultural University, Chengdu 611130, China d Sichuan tobacco company, Liangshanzhou company, Xichang 615000, China HIGHLIGHTS G R A P H I C A L ABSTRACT • Glutathione and phenylpropanoid path- ways were active under Cd stress. • Antioxidant, GSH and lignin contents were increased under Cd stress. • Cell wall of rice root was thickened under Cd stress. • The expressions of OsIRT1, OsNRAMP5 and OsHMA2 were down-regulated. • Enhanced lignin content lead to higher yield and lower Cd in rice grain. A R T I C L E INFO Editor: Wagner L Araújo Keywords: Heavy metal Phenylpropane Transcriptome Cell wall Glutathione ABSTRACT Cadmium (Cd) is readily absorbed by rice and enters the food chain, posing a health risk to humans. A better understanding of the mechanisms of Cd-induced responses in rice will help in developing solutions to reduce Cd uptake in rice. Therefore, this research attempted to reveal the detoxifcation mechanisms of rice in response to Cd through physiological, transcriptomic and molecular approaches. The results showed that Cd stress restricted rice growth, led to Cd accumulation and H 2 O 2 production, and resulted cell death. Transcriptomic sequencing revealed glutathione and phenylpropanoid were the major metabolic pathways under Cd stress. Physiological studies showed that antioxidant enzyme activities, glutathione and lignin contents were signifcantly increased under Cd stress. In response to Cd stress, q-PCR results showed that genes related to lignin and glutathione biosynthesis were upregulated, whereas metal transporter genes were downregulated. Further pot experiment with rice cultivars with increased and decreased lignin content confrmed the causal relationship between increased lignin and reduced Cd in rice. This study provides a comprehensive understanding of lignin-mediated * Corresponding authors. E-mail addresses: yingjiewu@sicau.edu.cn (Y. Wu), w.changquan@163.com (C. Wang). 1 The authors contributed equally to this work. Contents lists available at ScienceDirect Journal of Hazardous Materials journal homepage: www.elsevier.com/locate/jhazmat https://doi.org/10.1016/j.jhazmat.2023.131931 Received 13 April 2023; Received in revised form 6 June 2023; Accepted 23 June 2023