Phytotoxicity and biotransformation of La₂O₃ nanoparticles in a terrestrial plant cucumber (Cucumis sativus).
With the increasing applications of metal-based nanoparticles in various commercial products, it is necessary to address their environmental fate and potential toxicity. In this work, we assessed the phytotoxicity of lanthanum oxide (La₂O₃) NPs to cucumber plants and determined its distribution and biotransformation in roots by TEM and EDS, as well as STXM and NEXAFS. LaCl₃ was also studied as a reference toxicant. La₂O₃ NPs and LaCl₃ were both transformed to needle-like LaPO₄ nanoclusters in the intercellular regions of the cucumber roots. In vitro experiments demonstrated that the dissolution of La₂O₃ NPs was significantly enhanced by acetic acid. Accordingly, we proposed that the dissolution of NPs at the root surface induced by the organic acids extruded from root cells played an important role in the phytotoxicity of La₂O₃ NPs. The reactions of active NPs at the nano-bio interface should be taken into account when studying the toxicity of dissolvable metal-based nanoparticles.
Key Laboratory for Biological Effects of Nanomaterials and Nanosafety, Key Laboratory of Nuclear Analytical Techniques, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, P. R. China.
Yuhui
Y
Ma
Xiao
X
He
Peng
P
Zhang
Zhiyong
Z
Zhang
Zhi
Z
Guo
Renzhong
R
Tai
Zijian
Z
Xu
Lijuan
L
Zhang
Yayun
Y
Ding
Yuliang
Y
Zhao
Zhifang
Z
Chai
D000704:Analysis of Variance; D001711:Biotransformation; D018553:Cucumis sativus / Q000187:drug effects* / Q000378:metabolism*; D006651:Histocytochemistry; D007811:Lanthanum / Q000737:chemistry / Q000378:metabolism* / Q000633:toxicity*; D053768:Metal Nanoparticles / Q000737:chemistry / Q000633:toxicity*; D010087:Oxides / Q000737:chemistry / Q000378:metabolism* / Q000633:toxicity*; D018517:Plant Roots / Q000737:chemistry / Q000166:cytology / Q000187:drug effects
D010087:Oxides; C103829:lanthanum oxide; D007811:Lanthanum