Pedosphere 36(5): 1108--1118, 2026
ISSN 1002-0160/CN 32-1315/P
©2026 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Cell wall polysaccharides contribute significantly to differences in cadmium accumulation between two rice cultivars |
Changzhao CHEN1,3, Jieya SUN1,3, Jing YAN1, Chen TU1, Jiu HUANG3, Jin CHEN2, Xianjiao GUAN2, Lu ZHENG1, Junwei MA4, Yongming LUO1, Ren Fang SHEN1, Xiaofang ZHU1 |
1 State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China);
2 National Engineering and Technology Research Center for Red Soil Improvement, Key Laboratory of Crop Ecophysiology and Farming System for the Middle and Lower Reaches of the Yangtze River, Ministry of Agriculture and Rural Affairs, Institute of Soil & Fertilizer and Resources & Environment, Jiangxi Academy of Agricultural Sciences, Nanchang 330200 (China);
3 School of Environment Science and Spatial Informatics, China University of Mining and Technology, Xuzhou 221116 (China);
4 State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Institute of Environment, Resource, Soil and Fertilizers, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021 (China) |
| ABSTRACT |
| Cadmium (Cd) contamination in agricultural soils poses a significant threat to food safety, with rice being a major dietary source of Cd intake, particularly in Asia; however, the genetic and physiological mechanisms underlying cultivar-specific Cd accumulation, especially the differences between indica and japonica rice, remain poorly understood. In this study, rice cultivars indica Zhefu802 (ZF802) (Cd-sensitive) and japonica Nipponbare (Nip) (Cd-resistant) were used to compare Cd resistance and the level of Cd accumulation in 7-d-old rice seedlings after treatment with 1 μmol L-1 Cd in the presence or absence of 10 μmol L-1 nitric oxide (NO) scarvenger carboxy-PTIO (cPTIO) for 7 d in a hydroponic experiment. The results showed that Nip demonstrated superior Cd exclusion capacity, exhibiting 23.7% and 38.7% reductions in root and shoot Cd accumulation, respectively, along with 21.5% lower Cd translocation efficiency via xylem sap, compared to ZF802. Transcriptional profiling revealed cultivar-specific regulatory patterns: Nip downregulated metal uptake transporters (OsNRAMP1/5, OsZIP5/9, and OsIRT1/2), while upregulating efflux/vacuolar sequestration genes (OsCCX2 and OsHMA3), contrasting with ZF802's reliance on cell wall retention. Mechanistically, Nip exhibited 29.9% reduction in root cell wall Cd retention, concomitant with 53.5% lower hemicellulose content, whereas ZF802 enhanced Cd fixation through Cd-induced hemicellulose synthesis. Nitric oxide signaling emerged as a key regulatory factor, with ZF802 displaying 27.2% higher Cd-triggered NO production that promoted hemicellulose biosynthesis and Cd accumulation. Pharmacological inhibition through cPTIO-mediated NO scavenging normalized Cd accumulation in ZF802 to the equivalent level in Nip. These findings establish that coordinated regulation of transporter networks, cell wall polysaccharide remodeling, and NO-mediated signaling collectively determine cultivar-specific Cd partitioning patterns, providing molecular targets for developing low-Cd rice cultivars. |
| Key Words: Cd absorption,Cd contamination,Cd resistance,Cd translocation,NO signaling |
| Citation: Chen C Z, Sun J Y, Yan J, Tu C, Huang J, Chen J, Guan X J, Zheng L, Ma J W, Luo Y M, Shen R F, Zhu X F. 2026. Cell wall polysaccharides contribute significantly to differences in cadmium accumulation between two rice cultivars. Pedosphere. 36(5): 1108-1118. |
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