Open AccessAccumulation and transformation of inorganic and organic arsenic in rice and role of thiol-complexation to restrict their translocation to shoot
Author(s) -
Seema Mishra,
Jürgen Mattusch,
Rainer Wennrich
Publication year - 2017
Publication title -
scientific reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.24
H-Index - 213
ISSN - 2045-2322
DOI - 10.1038/srep40522
Subject(s) - shoot , arsenate , arsenic , arsenite , oryza sativa , transfer factor , chromosomal translocation , chemistry , botany , rhizome , genetic algorithm , phytochelatin , biology , glutathione , biochemistry , enzyme , organic chemistry , gene , evolutionary biology , immunology
Environmental contamination of arsenic (As) and its accumulation in rice ( Oryza sativa L.) is of serious human health concern. In planta speciation of As is an important tool to understand As metabolism in plants. In the present study, we investigated root to shoot As translocation and speciation in rice exposed to inorganic and methylated As. Arsenate (As V ) and methylarsonate (MA V ) were efficiently reduced to arsenite (As III ) and MA III , respectively in rice root and shoot but no trivalent form of dimethylarsinate (DMA V ) was detected. Further, up to 48 and 83% of root As in As V and MA V exposed plants, respectively were complexed with various thiols showing up to 20 and 16 As species, respectively. Several mixed As- and MA-complexes with hydroxymethyl-phytochelatin, DesGly-phytochelatin, hydroxymethyl-GSH and cysteine were identified in rice. Despite high complexation in roots, more As was translocated to shoots in MA V exposed plants than As V , with shoot/root As transfer factor being in order DMA V > MA V > As V . Moreover, in shoots 78% MA III and 71% As III were present as weakly bound species which is alarming, as MA III has been found to be more cytotoxic than As III for human and it could also be an important factor inducing straighthead (spikelet sterility disorder) in rice.