title: Arsenic accumulation and speciation in rice are affected by root aeration and variation of genotypes.
abstract: Root aeration, arsenic (As) accumulation, and speciation in rice of 20 different genotypes with regular irrigation of water containing 0.4 mg As l(-1) were investigated. Different genotypes had different root anatomy demonstrated by entire root porosity (ranging from 12.43% to 33.21%), which was significantly correlated with radial oxygen loss (ROL) (R=0.64, P<0.01). Arsenic accumulation differed between genotypes, but there were no significant differences between Indica and Japonica subspecies, as well as paddy and upland rice. Total ROL from entire roots was correlated with metal tolerance (expressed as percentage mean of control straw biomass, R=0.69, P<0.01) among the 20 genotypes; total As concentration (R=-0.67, P<0.01) and inorganic As concentration (R=-0.47, P<0.05) in rice grains of different genotypes were negatively correlated with ROL. There were also significant genotype effects in percentage inorganic As (F=15.8, P<0.001) and percentage cacodylic acid (F=22.1, P<0.001), respectively. Root aeration of different genotypes and variation of genotypes on As accumulation and speciation would be useful for selecting genotypes to grow in areas contaminated by As.
authors.affiliation: Croucher Institute for Environmental Sciences, and Department of Biology, Hong Kong Baptist University, Kowloon Tong, Hong Kong SAR, PR China.
authors.forename: Chuan
authors.initials: C
authors.lastname: Wu
authors.forename: Zhihong
authors.initials: Z
authors.lastname: Ye
authors.forename: Wensheng
authors.initials: W
authors.lastname: Shu
authors.forename: Yongguan
authors.initials: Y
authors.lastname: Zhu
authors.forename: Minghung
authors.initials: M
authors.lastname: Wong
mesh_terms: D000388:Air; D001151:Arsenic / Q000378:metabolism*; D018533:Biomass; D002851:Chromatography, High Pressure Liquid; D014644:Genetic Variation; D005838:Genotype; D012275:Oryza / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism; D018517:Plant Roots / Q000033:anatomy & histology / Q000378:metabolism*; D016062:Porosity; D013054:Spectrophotometry, Atomic
chemical_list: D001151:Arsenic; D010100:Oxygen