Growth and Cadmium Accumulation of Solanum nigrum L. Seedling were Enhanced by Heavy Metal-Tolerant Strains of Pseudomonas aeruginosa

Solanum nigrum L., a hyperaccumulator of cadmium (Cd), is regarded as a promising candidate for phytoremediation of heavy metal pollution. In the present study, the hairy roots of Solanum nigrum L. were selected as a model plant system to study the potential application of Iron-regulated Transporter Gene (IRT1) for the efficient phytoremediation of Cd pollution. The transgenic hairy roots of Solanum nigrum L. expressing the IRT1 gene from Arabidopsis thaliana were successfully obtained via the Agrobacterium tumegaciens-mediated method. Expression of IRT1 reduced Cd stress-induced phytotoxic effects. Significantly superior root growth, increased antioxidant enzyme activities, decreased reactive oxygen species (ROS) levels, and less cell apoptosis were observed in the transgenic hairy roots of Solanum nigrum L. compared to the wild-type lines under Cd stress. Enhanced Cd accumulation was also carried out in the transgenic hairy roots compared to the control (886.8 μg/g vs. 745.0 μg/g). These results provide an important understanding of the Cd tolerance mechanism of transgenic IRT1 hairy roots of Solanum nigrum L., and are of particular importance to the development of a transgenic candidate for efficient phytoremediation process.

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Comparative analyses of cadmium and zinc uptake correlated with changes in natural resistance-associated macrophage protein (NRAMP) expression in Solanum nigrum L. and Brassica rapa

Environmental Chemistry ◽

10.1071/en14078 ◽

2014 ◽

Vol 11 (6) ◽

pp. 653 ◽

Cited By ~ 14

Author(s):

Y. Song ◽

L. Hudek ◽

D. Freestone ◽

J. Puhui ◽

A. A. Michalczyk ◽

...

Keyword(s):

Heavy Metal ◽

Brassica Rapa ◽

Health Risks ◽

Contaminated Soils ◽

Molecular Mechanisms ◽

Solanum Nigrum ◽

Natural Resistance ◽

Potential Health ◽

Solanum Nigrum L ◽

Macrophage Protein

Environmental context Soils contaminated with metals can pose both environmental and human health risks. This study showed that a common crop vegetable grown in the presence of cadmium and zinc readily accumulated these metals, and thus could be a source of toxicity when eaten. The work highlights potential health risks from consuming crops grown on contaminated soils. Abstract Ingestion of plants grown in heavy metal contaminated soils can cause toxicity because of metal accumulation. We compared Cd and Zn levels in Brassica rapa, a widely grown crop vegetable, with that of the hyperaccumulator Solanum nigrum L. Solanum nigrum contained 4 times more Zn and 12 times more Cd than B. rapa, relative to dry mass. In S. nigrum Cd and Zn preferentially accumulated in the roots whereas in B. rapa Cd and Zn were concentrated more in the shoots than in the roots. The different distribution of Cd and Zn in B. rapa and S. nigrum suggests the presence of distinct metal uptake mechanisms. We correlated plant metal content with the expression of a conserved putative natural resistance-associated macrophage protein (NRAMP) metal transporter in both plants. Treatment of both plants with either Cd or Zn increased expression of the NRAMP, with expression levels being higher in the roots than in the shoots. These findings provide insights into the molecular mechanisms of heavy metal processing by S. nigrum L. and the crop vegetable B. rapa that could assist in application of these plants for phytoremediation. These investigations also highlight potential health risks associated with the consumption of crops grown on contaminated soils.

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Low molecular weight organic acids in root exudates and cadmium accumulation in cadmium hyperaccumulator Solanum nigrum L. and non-hyperaccumulator Solanum lycopersicum L.

AFRICAN JOURNAL OF BIOTECHNOLOGY ◽

10.5897/ajb11.1617 ◽

2011 ◽

Vol 10 (75) ◽

Cited By ~ 4

Author(s):

Tong Bao

Keyword(s):

Molecular Weight ◽

Organic Acids ◽

Solanum Lycopersicum ◽

Root Exudates ◽

Cadmium Accumulation ◽

Solanum Nigrum ◽

Low Molecular Weight ◽

Solanum Lycopersicum L ◽

Solanum Nigrum L

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Distribution and Redistribution of 109Cd and 65Zn in the Heavy Metal Hyperaccumulator Solanum nigrum L.: Influence of Cadmium and Zinc Concentrations in the Root Medium

Plants ◽

10.3390/plants8090340 ◽

2019 ◽

Vol 8 (9) ◽

pp. 340 ◽

Cited By ~ 3

Author(s):

Feller ◽

Anders ◽

Wei

Keyword(s):

Heavy Metals ◽

Heavy Metal ◽

Solanum Nigrum ◽

Root Medium ◽

Aerial Parts ◽

Edible Crops ◽

Cadmium Transport ◽

Solanum Nigrum L ◽

Zinc Concentrations

Heavy metal redistribution is relevant for the quality of edible crops and the suitability of hyperaccumulators for bioremediation. Root-to-shoot transfer via the xylem and redistribution in the aerial parts via the phloem differ between various heavy metals. In general, cadmium is more slowly released to the shoot than zinc (e.g., in wheat, bean, and lupin). However, rapid cadmium transport to the shoot was detected in the hyperaccumulator Solanum nigrum L. This is a key aspect in this article and might be important for bioremediation. The radionuclides 109Cd and 65Zn were used to investigate the respective influence of elevated cadmium or zinc in the root medium on the dynamics of the two heavy metals in S. nigrum. Although transport via the xylem to the leaves was similar for 109Cd and 65Zn, the further redistribution from older leaves to younger leaves, flowers, and fruits via the phloem was far less efficient for 109Cd than for 65Zn. Furthermore, the redistribution of 109Cd within the shoot was negatively influenced by increased cadmium (but not by increased zinc) concentrations in the nutrient medium. The redistribution of 65Zn in the shoot was selectively decreased by increased zinc concentrations (but generally not by cadmium).

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