Study on Copper Absorption, Accumulation and Tolerance Mechanism of Alfalfa
10.11895/j.issn.0253-3820.170124
- VernacularTitle:紫花苜蓿对铜的吸收、积累和耐受机制研究
- Author:
Liping ZHANG
;
Yating SHEN
- Keywords:
Alfalfa;
Copper;
Plant fractional extraction;
In-situ micro-X-ray fluorescence spectrometry;
Speciation
- From:Chinese Journal of Analytical Chemistry
2017;45(8):1129-1136
- CountryChina
- Language:Chinese
-
Abstract:
To reveal the mechanism of Cu enrichment of alfalfa, in-situ micro-X-ray fluorescence spectrometry (μ-XRF) and fractional extraction were used to explore in-situ Cu distribution information in alfalfa seedlings and different combination forms of Cu in organs.The results showed that alfalfa roots were enriched with Cu up to 12.06 mg/g, which was 8 times of stem and 4.9 times of leaves.The in-situ μ-XRF result showed that the root of alfalfa was the main site of enrichment of Cu, and there was a barrier of Cu at the rhizome junction to alleviate the toxic effect of excess Cu on the shoots.Excess Cu (more than 50 μmol/L) also inhibited the uptake of Zn and Ca in alfalfa, enhanced the uptake of Fe in alfalfa, but had no obvious effect on the uptake of K and Mn.Plant fractional extraction showed that the Cu in root cells was mainly fixed in the form of insoluble residues (41%) and cell wall chelate (20%), while in the stem, Cu existed as four forms including hydrophobic protein binding, cell wall binding state, residual state and water-soluble state, which further reduce the excess transport of Cu to the leaves.In the leaves, excess Cu in the leaf cells was mainly in the vacuole and insoluble residue to achieve tolerance and detoxification to Cu.
