期刊
JOURNAL OF EXPERIMENTAL BOTANY
卷 56, 期 415, 页码 1343-1349出版社
OXFORD UNIV PRESS
DOI: 10.1093/jxb/eri135
关键词
amino acids; metal hyperaccumulation; nickel (Ni); organic acids; Stackhousia tryonii Bailey
Field-collected, young plants of Ni hyperaccumulator Stackhousia tryonii, grown in a glasshouse for 20 weeks, were exposed to low- (available Ni concentration in the native serpentine soil, i.e. 60 mu g g(-1) dry soil) and high- (external application of 1000 ppm) Ni concentrations in the substrate. Nickel concentration in the freeze-dried leaf tissues increased from 3700 mu g g(-1) to 13 700 mu g g(-1) with soil Ni supplementation, of which > 60% was extracted with dilute acid (0.025 M HCl). Nickel supplementation also elicited a 575%, 211%, and 37% increase in the final concentrations of oxalic, citric, and malic acids, respectively, in leaf tissues. Malic acid was the dominant organic acid, followed by citric and oxalic acids. The molar ratio of Ni to malic acid was 1.0, consistent with a role for malate as a ligand for Ni in hyperaccumulating plants, supporting detoxification/transport and storage of this heavy metal in S. tryonii. The total amino acid concentrations in the xylem sap did not change with Ni supplementation (21.7 +/- 3.7 mM and 17.9 +/- 5 mM, respectively, for low- and high-nickel-treated plants). Glutamine was the major amino acid in both the low- and high-Ni-treated plants. The concentration of glutamine decreased by > 60%, with a corresponding increase in alanine, aspartic acid, and glutamic acid, on exposure to high Ni. A role of amino acids in Ni complexation and transport in S. tryonii is not immediately apparent.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据