Liu Xiaoli, Zhang Shuzhen, Shan Xiaoquan, Zhu Yong-Guan
State Key Laboratory of Environmental Toxicology and Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085, China.
Chemosphere. 2005 Oct;61(2):293-301. doi: 10.1016/j.chemosphere.2005.01.088.
Effects of different concentrations of arsenite and arsenate (0-16 mg/l) on seed germination, relative root length and shoot height, arsenic accumulation in young seedlings, alpha-amylase, beta-amylase and total amylolytic activity in wheat were investigated in order to elucidate the toxicity of arsenic in the early developmental stage. Germination percentages of different wheat varieties had different responses to arsenic species and decreased significantly with increasing arsenic concentrations except Duokang 1. Relative root length (RRL) and relative shoot height (RSH) of wheat seedlings decreased with increasing concentrations of arsenite and arsenate. The relative root lengths were correlated with the relative shoot heights for arsenite (r2 = 0.79) and arsenate (r2 = 0.77). Arsenic uptake by seedlings increased with the increasing concentrations of arsenite or arsenate and followed the Michaelis-Menten kinetics function. The average total amylolytic activity and beta-amylase activity had no significant difference comparable to that of controls at the concentration 2 mg/l arsenite or arsenate, but decreased apparently when the concentration was higher than 2 mg/l. Whereas the alpha-amylase activity decreased with increasing concentrations of arsenite or arsenate over the whole concentration range. Arsenite decreased all the endpoints more remarkably than arsenate. In comparison, shoot height and root length were more sensitive to arsenic than other endpoints and might be used as indicators for arsenic toxicity.
研究了不同浓度（0 - 16毫克/升）的亚砷酸盐和砷酸盐对小麦种子萌发、相对根长和苗高、幼苗砷积累、α-淀粉酶、β-淀粉酶及总淀粉酶活性的影响，以阐明砷在小麦早期发育阶段的毒性。不同小麦品种的发芽率对砷形态有不同反应，除多抗1号外，发芽率均随砷浓度升高而显著降低。小麦幼苗的相对根长（RRL）和相对苗高（RSH）随亚砷酸盐和砷酸盐浓度升高而降低。亚砷酸盐（r2 = 0.79）和砷酸盐（r2 = 0.77）的相对根长与相对苗高相关。幼苗对砷的吸收随亚砷酸盐或砷酸盐浓度升高而增加，并符合米氏动力学函数。在亚砷酸盐或砷酸盐浓度为2毫克/升时，平均总淀粉酶活性和β-淀粉酶活性与对照相比无显著差异，但当浓度高于2毫克/升时明显降低。而在整个浓度范围内，α-淀粉酶活性随亚砷酸盐或砷酸盐浓度升高而降低。亚砷酸盐比砷酸盐更显著地降低所有指标。相比之下，苗高和根长对砷比其他指标更敏感，可作为砷毒性的指标。
