Reducing Cd accumulation in rice grain with foliar application of glycerol and its mechanisms of Cd transport inhibition

• Published in: Chemosphere (Oxford) Vol. 258; p. 127135
• Main Authors: Yang, Junying, Chen, Xian, Lu, Wencong, Chen, Runcheng, Liu, Mengnan, Yao, Huanli, Li, Jihong, Hong, Jiale, Mao, Xiaoyun
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.11.2020
• Subjects: Cadmium; Glycerol; Rice; Glycerol; Cadmium; Rice
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2020.127135

Excessive cadmium (Cd) in rice grain has become a major global public health problem. Here, the effect of foliar glycerol application on Cd accumulation in brown rice was examined. Various spraying concentrations of glycerol between 0.4mM and 50mM were investigated and the results showed that 0.8 mM was the best application concentration for decreasing Cd content in brown rice. After different application period experiment, filling stage was considered as the optimal spraying time. 0.4mM–5mM glycerol application one time at the filling stage could significantly reduce Cd concentration in brown rice by 28.5%–60.4%. Cd transport factors (the ratio of brown rice and flag leaf/node) were decreased by 48.5% and 27.3%, respectively, with glycerol application. Glycerol application also significantly increased Cd concentration in soluble fraction in flag leaf while reduced inorganic Cd and water-soluble Cd in both flag leaf and stem. Our results showed foliar spraying glycerol inhibited Cd transport to brown rice through Cd compartmentalisation in the vacuole and transformation of cadmium chemical form. This study may provide a new method to effectively alleviate the problem of excessive Cd in rice. [Display omitted] •Foliar spraying of glycerol reduced rice grain Cd accumulation by 60.4%.•Foliar glycerol was most efficacious at filling and boosted rice growth and yield.•Glycerol reduced nodal reactivation and foliar reorientation Cd transport factors.•Glycerol leaf spray promoted Cd vacuolisation in cells of rice stem.•Glycerol spray lowered Cd mobility by inducing its binding to pectate and proteins.