title: Toxic effect of cadmium adsorbed by different sizes of nano-hydroxyapatite on the growth of rice seedlings.
abstract: Information regarding the toxic effects of cadmium (Cd) adsorbed by nano-hydroxyapatite (NHAP-Cd) on the growth of crop plants remain limited. We investigated the mechanism of NHAP-Cd (diameters, 20 and 40nm; NHAP20-Cd and NHAP40-Cd, respectively) phytotoxicity. Rice seedlings treated with Cd and NHAP20-Cd showed more severe growth retardation compared to those treated with NHAP40-Cd, for the same Cd concentration. Transmission electron microscopy revealed NHAP in the seedlings. The nanoparticles entered the rice seedlings with no Cd2+signals in the NHAP treatments compared to -0.47pmolcm-2s-1of Cd2+fluxes in the Cd treatment. The higher Cd2+content in the leaves and mesocotyl of NHAP20-Cd-treated rice seedlings suggested that smaller NHAP-Cd can translocate easily to the aboveground parts. Further, NHAP-Cd increased oxidative stress, which was determined as catalase activity changes in this study. Thus, NHAP-Cd particles in the growth medium can be transported to rice seedlings and cause toxicity.
authors.affiliation: Agro-environmental Protection Institute, Ministry of Agriculture, Key Laboratory of Production Environment Quality, Ministry of Agriculture of China, Tianjin, 300191, China.
authors.forename: Yifan
authors.initials: Y
authors.lastname: Huang
authors.affiliation: The New Zealand Institute for Plant and Food Research Limited, Private Bag 4704, Christchurch, 8140, New Zealand.
authors.forename: Weiwen
authors.initials: W
authors.lastname: Qiu
authors.affiliation: Agro-environmental Protection Institute, Ministry of Agriculture, Key Laboratory of Production Environment Quality, Ministry of Agriculture of China, Tianjin, 300191, China.
authors.forename: Zhihong
authors.initials: Z
authors.lastname: Yu
authors.affiliation: Agro-environmental Protection Institute, Ministry of Agriculture, Key Laboratory of Production Environment Quality, Ministry of Agriculture of China, Tianjin, 300191, China. Electronic address: forestman1218@163.com.
authors.forename: Zhengguo
authors.initials: Z
authors.lastname: Song
mesh_terms: D000327:Adsorption; D002104:Cadmium / Q000737:chemistry* / Q000493:pharmacokinetics / Q000633:toxicity*; D002374:Catalase / Q000378:metabolism; D017886:Durapatite / Q000737:chemistry* / Q000493:pharmacokinetics / Q000633:toxicity; D053758:Nanoparticles / Q000737:chemistry* / Q000633:toxicity; D012275:Oryza / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D010316:Particle Size; D018515:Plant Leaves / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D036226:Seedlings / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism
chemical_list: D002104:Cadmium; D017886:Durapatite; D002374:Catalase
keywords: Hydroxyapatite-adsorbed Cd(2+); Nanoparticle; Rice seedling; Toxicity