Search

To improve the selenium (Se) absorption of grape, in this study, a pot experiment was carried out to study the effects of intercropping with four Solanum sect. Solanum (Solanaceae), including Solanum nigrum var. humile, Solanum diphyllum, Solanum nigrum, and Solanum alatum, on the Se absorption of 'Summer Black' grapevine. Intercropping increased the malondialdehyde contents in 'Summer Black' grapevine, which in turn reduced the biomass, photosynthetic pigments (chlorophyll a, chlorophyll b, carotenoid) contents, and antioxidant enzymes (superoxide dismutase, peroxidase, and catalase) activities of 'Summer Black' grapevine. Except S. alatum, intercropping with S. nigrum var. humile, S. diphyllum, and S. nigrum increased the Se content in 'Summer Black' grapevine, which increased the shoot Se content of 'Summer Black' grapevine by 56.2%, 18.1%, and 45.1%, respectively, compared with the monoculture. Additionally, correlation and grey relational analyses revealed that the root Se content was the most closely associated with the shoot Se content. In conclusion, intercropping with S. nigrum var. humile, S. diphyllum, and S. nigrum promote the Se accumulation in 'Summer Black' grapevine but inhibit its growth, and intercropping with S. nigrum var. humile has the best effect on the improvement of Se level in 'Summer Black' grapevine, which can be used for Se‐enriched grape production. [ABSTRACT FROM AUTHOR]

Perilla frutescens is widely distributed and considered to be an accumulator plant for heavy metals, including cadmium (Cd). However, the phytoremediation ability of P. frutescens is lower than the other hyperaccumulators or accumulators. To improve the phytoremediation ability of P. frutescens to Cd, different concentrations of abscisic acid (ABA) were applied to P. frutescens grown in Cd-contaminated soil to improve its phytoremediation ability. The concentrations of 5, 10, and 20 µmol/L ABA increased the shoot biomass and contents of photosynthetic pigments (chlorophyll a, chlorophyll b, total chlorophyll and carotenoids) of P. frutescens, while 1 µmol/L ABA had no significant effect. Different concentrations of ABA enhanced the activities of superoxide dismutase and peroxidase of P. frutescens but had no significant effect on the activity of catalase, while it reduced the contents of soluble protein and malondialdehyde. Different concentrations of ABA increased the contents of Cd in various organs of P. frutescens, and the contents of Cd in stems, leaves, and shoots tended to increase in parallel with the concentrations of ABA. Varying amounts of ABA also increased the Cd extractions by various organs of P. frutescens, and the concentrations of 1, 5, 10, and 20 μmol/L ABA increased the shoot Cd extraction by 11.26%, 32.24%, 36.18%, and 35.96%, respectively, compared with the control. Therefore, ABA could improve the ability of P. frutescens to perform phytoremediation when grown in Cd-contaminated soil, and the optimal concentration of ABA was 5 μmol/L. [ABSTRACT FROM AUTHOR]

To study the effects of selenium on physiology, Prunus davidiana seedlings were treated with the irrigation of different selenium concentrations solution. The result showed that the photosynthetic pigment content was relatively higher at selenium concentrations of 0, 0.05 and 0.1 mg/L except for carotenoid content which was the highest at 0.1 mg/L but the lowest in control seedlings. In terms of antioxidant enzyme activity, the activities of peroxidase (POD), catalase (CAT) and superoxide dismutase (SOD) in selenium-treated seedlings were all higher than that in control seedlings and especially at the selenium concentration of 1 mg/L. The soluble protein content accumulated most at 0.25 mg/L selenium concentration. The content of malondialdehyde (MDA), as membrane lipid peroxidation index, was the lowest at selenium concentration of 0.5 mg/L. In a word, irrigating lower selenium concentrations could increase the photosynthetic pigment content and higher selenium concentrations enhanced the antioxidant enzyme activity to increase cell protection and kept the P. davidiana seedlings good growth and resistance to adverse environments.

The selenium accumulation characteristics of Solanum nigrum with different ploidy were studied by the pot experiment, and the biomass, selenium content and selenium accumulation of diploid (Solanum photeinocarpum), tetraploid (Solanum photeinocarpum) and hexaploid (Solanum nigrum) plants were determined, the results showed that there was a difference between the biomass and selenium content of three kinds of ploidy plants of S. nigrum. The biomass of various organs and shoots of hexaploid S. nigrum plants was significantly higher than that of tetraploid and diploid plants. In terms of selenium content and selenium accumulation, the hexaploid plants had the highest selenium content and selenium accumulation in stems, leaves and shoots. After comprehensive comparison, the hexaploid S. nigrum has large biomass and strong selenium-enriching ability, so it can be used as an excellent plant material for soil selenium absorption and transformation.

To study the cadmium accumulation characteristics of Solanum nigrum with different ploidies, the biomass, cadmium content and cadmium accumulation of diploid (Solanum photeinocarpum), tetraploid (Solanum photeinocarpum) and hexaploid (Solanum nigrum) were measured by a pot experiment. The results showed that the biomass of roots, stems, leaves and shoots of S. nigrum plants with different ploidy all ranked as follows: hexaploid > tetraploid > diploid. Cadmium content and cadmium accumulation in stems, leaves and shoots of hexaploid plants were significantly higher than those in tetraploid and diploid plants, and the cadmium translocation factor and translocation accumulation factor of hexaploid were the largest, too. Therefore, hexaploid S. nigrum had a highest ability to extract and transport cadmium, which can be used as an ideal plant for remediation of cadmium-contaminated soil.

In order to study the changes of the photosynthetic pigment content, antioxidant enzyme activity and osmotic adjuster content, the Prunus davidiana seedlings were cultured into Hoagland nutrient solution which added various concentrations of iron solution. Then the results showed that photosynthetic pigment content and antioxidant enzyme activity were all higher in iron-treated P. davidiana seedlings, compared with that in control seedlings. When increased iron concentration up to 10 mg/L, the chlorophyll a, chlorophyll b and the total chlorophyll content gradually rose, but decreased at iron concentrations of 20, 30, 40 and 60 mg/L. Irrigating iron concentration of 60 mg/L was the best way to increase the activity of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT), and malondialdehyde (MDA) content. But for chlorophyll a/b ratio, it was the highest in no-iron seedlings. Moreover, the soluble protein content was the highest at iron concentration of 30 mg/L, but the lowest at 10 mg/L. Thus, the study concluded that irrigating iron solution could improve the growth and resistance to adverse circumstances of P. davidiana seedlings.

In order to improve the nutrients absorption of grape seedlings under cadmium (Cd) stress, the effects of Solanum nigrum, Crassocephalum crepidioides and Bidens pilosa straws on the nutrients content of soil and grape seedlings under Cd stress were studied by pot experiment. According to the results, the activity of soil phosphatase, soil catalase and soil sucrose by soil application of straws observed higher than CK to varying degrees. And soil application of straws increased the contents of soil alkaline nitrogen and available phosphorus in different degrees, while soil application of B. pilosa straws decreased the content of soil available potassium. In addition, the soil application of straws had a certain promoting effect on the total nitrogen content, total phosphorus content and total potassium content of grape seedlings compared with the CK. Among all treatments, C. crepidioides straws maximized the nutrients content in the shoots of grape seedlings, which could provide reference for grape cultivation in Cd-contaminated areas.

The aim of this study was to determine the effects of spraying an algal biostimulant at different concentrations (0, 600-, 900-, 1200-, and 1500-fold dilutions) on the growth and cadmium (Cd) accumulation characteristics of accumulator plant Nasturtium officinale. In a pot experiment, application of the algal biostimulant at all concentrations promoted the growth of N. officinale by increasing the root and shoot biomasses, and the 600-fold dilution of the algal biostimulant had the strongest effect. At all concentrations, the algal biostimulant had no significant effect on the Cd content in roots of N. officinale, and increased the Cd extraction by roots. However, all concentrations of the algal biostimulant except for the 1500-fold dilution decreased the Cd content in shoots and Cd extraction by shoots. The N. officinale plants treated with the 600-fold dilution of the algal biostimulant had the lowest shoot Cd contents and Cd extraction by shoots. The algal biostimulant also increased the contents of photosynthetic pigments (chlorophyll a, total chlorophyll, and carotenoids) in leaves of N. officinale to varying degrees. Different concentrations of algal biostimulant reduced the superoxide dismutase activity, peroxidase activity, and malondialdehyde content of N. officinale, but enhanced the catalase activity, soluble protein content, and relative conductivity. Overall, the 600-fold dilution had the strongest effect on the growth and Cd accumulation characteristics of N. officinale, but did not enhance the phytoremediation ability of N. officinale for growth in Cd-contaminated soil. These results show that this algal biostimulant can promote the growth and reduce the Cd uptake of N. officinale, which is benefit for N. officinale safety production as a wild vegetable in Cd-contaminated soils. [ABSTRACT FROM AUTHOR]

To investigate the effects of intercropping with hyperaccumulator on cadmium (Cd) accumulation of non-hyperaccumulator, a pot experiment was conducted to study the effects of intercropping with three ploidies of hyperaccumulator Solanum species on the growth and cadmium uptake of Cyphomandra betacea seedlings. The hyperaccumulators Solanum photeinocarpum (diploid), Solanum nigrum (hexaploid), and colchicine-induced tetraploid S. photeinocarpum were intercropped with C. betacea seedlings under Cd-contaminated soil conditions. Intercropping with three ploidies of Solanum species decreased the root, stem, leaf, and shoot biomass of C. betacea seedlings. Intercropping with three ploidies of Solanum species also decreased the photosynthetic pigment contents (chlorophyll a, chlorophyll b, total chlorophyll, and carotenoid) in C. betacea seedlings but increased the activities of antioxidant enzymes (superoxide dismutase, peroxidase, and catalase) and soluble protein content of C. betacea seedlings. Intercropping decreased the Cd content in C. betacea seedlings. The lowest level was observed after intercropping with the hexaploid species, while the Cd contents and extraction amount of three ploidies of Solanum increased by decreasing the pH of soil and increasing concentration of soil exchangeable Cd. Therefore, intercropping three ploidies of Solanum species could inhibit the Cd uptake of C. betacea, and the hexaploid (S. nigrum) was the best choice. [ABSTRACT FROM AUTHOR]

Cuttings are asexual reproduction, and different vegetative organs of the plant can be selected as cuttings to grow into a new plant. Growth and cadmium (Cd) accumulation of cuttings taken from tomato (Solanum lycopersicum) plants non-grafted or grafted onto five different rootstocks were studied in a pot experiment. 'Zhongyanhong 6ʹ and 'Hongyu F1ʹ were non-grafted (CK) and were grafted onto Solanum torvum, Totosga, 'Dalishengen', 'Banzhen 18ʹ and 'Guozhen 1ʹ, respectively, planted in pots without Cd-contaminated soil. Cuttings were taken after one month, then grown in Cd-contaminated soil (10 mg kg−1) for three months. In 'Zhongyanhong 6ʹ cuttings, compared with non-grafted, grafting onto five rootstocks increased plant dry weight, grafting onto 'Banzhen 18ʹ and S. torvum increased plant height, grafting onto 'Banzhen 18ʹ and 'Guozhen 1' increased fruit fresh weight, grafting onto 'Guozhen 1ʹ and 'Dalishengen' reduced Cd content in fruit. In 'Hongyu F1ʹ cuttings, compared with non-grafted, grafting onto five rootstocks increased plant dry weight, grafting onto Totosga increased plant height, grafting onto S. torvum and Totosga increased fruit fresh weight, grafting onto 'Banzhen 18ʹ, 'Dalishengen', S. torvum and Totosga decreased Cd content in fruit. Cutting after grafting affects growth and Cd accumulation of tomato, which can provide a theoretical basis for the safe production of nightshade vegetables. [ABSTRACT FROM AUTHOR]

A pot experiment was designed to assess the effects of different rootstocks on cadmium (Cd) accumulation and the growth of the post-grafting generations of Brassica juncea var. megarrhiza. Four treatments, including ungrafted and B. juncea var. megarrhiza as the scion grafted on the rootstocks of Brassica napus, Brassica chinensis and Brassica campestris respectively, were analysed. The three grafting treatments decreased the content of Cd in the first post-grafting generations of B. juncea var. megarrhiza but increased the length of roots, tuberous roots and leaves, and tuberous root diameters, as well as the biomass of the various organs and edible parts. In addition, the grafted rootstocks could enhance the level of photosynthetic pigments and the activity of peroxidase but reduce the activities of superoxide dismutase and catalase and the soluble protein content of the first post-grafting generations of B. juncea var. megarrhiza. The different rootstocks grafts could also decrease the available concentration of Cd in the soil but increase the soil pH. Therefore, the grafting could decrease the accumulation of cadmium in the post-grafting generation of B. juncea var. megarrhiza, and the graft on B. campestris was the most effective. [ABSTRACT FROM AUTHOR]

Cadmium (Cd) contamination of orchard soils is a global problem that has been increasing. To decrease the Cd accumulation in fruits, intercropping the orchard crops with hyperaccumulator plants has been used for soil remediation. A pot and a field experiment were conducted to study the effects of intercropping the potential Cd-hyperaccumulator Solanum photeinocarpum and its post-grafting generations with loquat (Eriobotrya japonica) on the growth and Cd uptake of these two plant species. In the pot experiment, intercropping improved the biomass, Cd content, Cd extraction, and root-to-shoot Cd translocation in both species. Intercropping increased the DNA methylation levels, antioxidant enzyme activity, and soluble protein content of loquat seedlings. These results indicate that intercropping could improve the phytoremediation of S. photeinocarpum and its post-grafting generations and increase the Cd uptake in loquat seedlings. In the field experiment, intercropping increased the Cd contents in the old branches, while it decreased that in the young branches and fruits of loquat. These findings indicate that intercropping could increase the Cd uptake in old tissues but reduce the Cd uptake in young tissues and fruits of loquat. So, intercropping loquat with S. photeinocarpum and its post-grafting generations could be used in Cd-contaminated orchards. Intercropping the potential Cd-hyperaccumulator Solanum photeinocarpum and its post-grafting generations with loquat mutually promoted the growth of two plant species, and also promoted the cadmium uptakes in S. photeinocarpum and old branches of loquat, while inhibited the Cd uptake in the loquat young tissues (young branches and fruits). These results are the new findings of the intercropping. [ABSTRACT FROM AUTHOR]

To reduce the cadmium (Cd) uptake in fruit tree Cyphomandra betacea Sendt., the effects of different salicylic acid (SA) concentrations (0, 100, 150, 200, and 250 mg L−1) on the physiological and Cd accumulation characteristics of hydroponically grown C. betacea seedlings under Cd stress were studied. Under SA concentrations of 150, 200, and 250 mg L−1, the biomass, photosynthetic pigments (chlorophyll a, chlorophyll b, and carotenoid) contents as well as the photosynthetic parameters (net photosynthetic rate, transpiration rate, stomatal conductance, and intercellular CO2 concentration) of C. betacea seedlings were significantly higher than that of the control. The superoxide dismutase and catalase activities of C. betacea seedlings first increased and then decreased with increasing SA concentration, while the peroxidase activity and soluble protein content followed the opposite trend. When SA was applied at concentrations of 100, 150, and 200 mg L−1, the Cd contents in C. betacea seedlings were lower than in the control, whereas 250 mg L−1 SA increased C. betacea seedlings Cd contents. Taken together, the results of this experiment indicate that the biomass and Cd contents of C. betacea seedlings respectively reached a maximum and minimum under the action of SA at 150 mg L−1, a concentration thus beneficial for cultivating C. betacea seedlings under Cd stress. [ABSTRACT FROM AUTHOR]

To identify whether the auxin treatment could promote the growth and reduce the cadmium (Cd) of fruit trees, the effects of different concentrations of indole acetic acid (IAA, one of the auxin) on the biomass, Cd content, photosynthetic pigment content, photosynthetic characteristics, antioxidant enzyme activity, and soluble sugars content in Cyphomandra betacea seedlings under Cd stress were studied. As the IAA concentration increased, the biomass, photosynthetic pigment content, soluble sugars content, and net photosynthetic rate of C. betacea seedlings tended to first increase and then decrease, with maximum values in the 60 mg/L IAA treatment. The Cd contents in different organs decreased and then increased with increasing IAA concentrations, with the minimum value in the 60 mg/L IAA treatment. Compared with the control, IAA treatments enhanced the activities of peroxidase and superoxide dismutase in the leaves of C. betacea seedlings and decreased the soluble protein content. Therefore, IAA treatments promoted growth, enhanced Cd resistance, and decreased the Cd content in C. betacea. The 60 mg/L IAA treatment was the most effective for promoting growth and decreasing the Cd content in C. betacea. [ABSTRACT FROM AUTHOR]