PRIME EDITING - a new method of editing genes / PRIME EDITING - nowa metoda edycji genów.

The Prime Editing method introduces the expected manipulations within a given genome with a Cas9-nicase and pegRNA structure and a reverse transcriptase, which is responsible for the synthesis of the segment, which is then incorporated into the edited strand. This technique is based on the previously discovered CRISPR/Cas9 method. It differs from CRISPR/Cas9 in the absence of double cracks within the DNA helix, which is due to its complex structure, including the presence of additional elements, i. e. the reverse transcriptase and the matrix within the pegRNA. PE is used to modify the DNA double helix. The work deals mainly with the creation and improvement as well as testing of the modern Prime Editing method. Information on the structure and functioning of the system is provided, as well as the research carried out so far with the use of PE, carried out within the genomes of cells derived from plant, animal, and human organisms, is described. The paper also contains information on the potential benefits and hopes related to the use of this innovative method.

Integrated survey on the heavy metal distribution, sources and risk assessment of soil in a commonly developed industrial area.

The Jiangzhe Area was relatively common area that rely on industrial process for rapid development with serious heavy metals contamination. This study investigated the spatial, vertical and speciation distribution, correlation of heavy metals, as well as assessed pollution and health risks in three representative contamination industries at Jingjiang (electroplating site), Taizhou (e-waste recycling site) and Wenzhou (leather production site) in the Jiangzhe Area. The results indicated that the Cr(VI) pollution was serious in all three sites and there was a tendency to gradually decrease with depth. As for other heavy metals, not only the total concentration, but also the addition of acid soluble and reducible speciation generally decreased with soil depth at Jingjiang and Taizhou sites. Significantly positive correlations supported by correlation analysis were detected between the following elements: Cu-Ni (p < 0.01), Cr(VI)-Ni (p < 0.05) and Cr(VI)-Cu (p < 0.05) at Jingjiang site, Cu-Ni (p < 0.01), Cu-Cd (p < 0.01) and Ni-Cd (p < 0.05) at Taizhou site indicating possibly the same sources and pathways of origin, while the significantly negative correlation of Cd-Ni (p < 0.05) at Wenzhou site meaning the different sources. As regards the pollution assessment of topsoil, the mean PI value indicated that Cr(VI) contaminated severe in all three sites. In general, Jingjiang site was severe pollution (4.06), while Taizhou and Wenzhou (2.27 and 2.66) were moderate pollution, as NIPI value shown. In terms of health risk assessment that received much attention, non-carcinogenic risks caused by Pb contamination were significant for children at Jingjiang and Taizhou sites, with the HI values of 3.42E+ 00 and 2.03E+ 00, respectively. Ni caused unacceptable carcinogenic risk for both adults and children at all three sites. The present study can help to better understand the contamination characteristics of heavy metals in the commonly developed industrial area, and thus to control the environmental quality, so as to truly achieve the goal of "Green Deal objectives ".

Natural Molecular Mechanisms of Plant Hyperaccumulation and Hypertolerance towards Heavy Metals.

The main mechanism of plant tolerance is the avoidance of metal uptake, whereas the main mechanism of hyperaccumulation is the uptake and neutralization of metals through specific plant processes. These include the formation of symbioses with rhizosphere microorganisms, the secretion of substances into the soil and metal immobilization, cell wall modification, changes in the expression of genes encoding heavy metal transporters, heavy metal ion chelation, and sequestration, and regenerative heat-shock protein production. The aim of this work was to review the natural plant mechanisms that contribute towards increased heavy metal accumulation and tolerance, as well as a review of the hyperaccumulator phytoremediation capacity. Phytoremediation is a strategy for purifying heavy-metal-contaminated soils using higher plants species as hyperaccumulators.

The effects of different electrode materials on seed germination of Solanum nigrum L. and its Cd accumulation in soil.

The effects of different electrode on Solanum nigrum L. seed germination were determined. The result showed that germination percentage (GP) of seeds in treatment T2 (titanium electrode) was 26.6% higher than in control (CK, without electric field). High potassium and calcium concentrations were beneficial for seed enzymatic activity in treatment T2, which could partly explain the increase in GP. Cd accumulation (µg/pot) in S. nigrum treated with any electric field was significantly higher (p<0.05) than in CK without electric field. Specifically, Cd accumulation under the treatment T3 (stainless steel electrode) was the highest both in roots and shoots; this accumulation in shoots and roots were 74.7 % and 67.4 % higher for stainless steel than in CK. This increase must have been associated with a higher Cd concentration in plants and did not exert a significant effect on the biomass. In particular, Cd concentrations in roots and shoots under stainless steel treatment were both significantly higher than in CK (p<0.05), which had to be related to the higher available Cd concentration in the soil in the middle region. Furthermore, it could be attributed to altered soil pH and other soil properties. Moreover, none of the biomasses were significantly affected (p<0.05) by different electrode materials compared to CK.

CRISPR/Cas as the intelligent immune system of bacteria and archea / CRISPR/Cas jako inteligentny system immunologiczny bakterii i archea.

The invention of CRISPR is considered to be one of the most breakthrough discoveries in recent years in the history of biology, biotechnology, medicine, as well as the pharmaceutical and agricultural industries. The methods developed using CRISPR create new, previously unattainable possibilities that can significantly improve the quality of life. From the invention of this intelligent immune system to the present day, much research has been done using the CRISPR/Cas systems. The result of these studies was the development of a modern tool for genetic manipulation, which allows for the introduction of many modifications within the DNA, which may contribute to the silencing of the expression of given genes or their overexpression through e.g. mutations or deletions. The paper describes the application of the method for genetic manipulation with the use of the second class system ­ CRISPR/Cas9 and the advantages of this method and its advantage over the previously used genetic engineering tools, as well as its limitations and disadvantages, which significantly limit the possibility of its application. The potential use of the method was also presented as well as the research carried out with the use of CRSPR/Cas9.

Horizontal Gene Transfer Involving Chloroplasts.

Horizontal gene transfer (HGT)- is defined as the acquisition of genetic material from another organism. However, recent findings indicate a possible role of HGT in the acquisition of traits with adaptive significance, suggesting that HGT is an important driving force in the evolution of eukaryotes as well as prokaryotes. It has been noted that, in eukaryotes, HGT is more prevalent than originally thought. Mitochondria and chloroplasts lost a large number of genes after their respective endosymbiotic events occurred. Even after this major content loss, organelle genomes still continue to lose their own genes. Many of these are subsequently acquired by intracellular gene transfer from the original plastid. The aim of our review was to elucidate the role of chloroplasts in the transfer of genes. This review also explores gene transfer involving mitochondrial and nuclear genomes, though recent studies indicate that chloroplast genomes are far more active in HGT as compared to these other two DNA-containing cellular compartments.

SPInDel Analysis of the Non-Coding Regions of cpDNA as a More Useful Tool for the Identification of Rye (Poaceae: Secale) Species.

Secale is a small but very diverse genus from the tribe Triticeae (family Poaceae), which includes annual, perennial, self-pollinating and open-pollinating, cultivated, weedy and wild species of various phenotypes. Despite its high economic importance, classification of this genus, comprising 3-8 species, is inconsistent. This has resulted in significantly reduced progress in the breeding of rye which could be enriched with functional traits derived from wild rye species. Our previous research has suggested the utility of non-coding sequences of chloroplast and mitochondrial DNA in studies on closely related species of the genus Secale. Here we applied the SPInDel (Species Identification by Insertions/Deletions) approach, which targets hypervariable genomic regions containing multiple insertions/deletions (indels) and exhibiting extensive length variability. We analysed a total of 140 and 210 non-coding sequences from cpDNA and mtDNA, respectively. The resulting data highlight regions which may represent useful molecular markers with respect to closely related species of the genus Secale, however, we found the chloroplast genome to be more informative. These molecular markers include non-coding regions of chloroplast DNA: atpB-rbcL and trnT-trnL and non-coding regions of mitochondrial DNA: nad1B-nad1C and rrn5/rrn18. Our results demonstrate the utility of the SPInDel concept for the characterisation of Secale species.

Strengthening role and the mechanism of optimum nitrogen addition in relation to Solanum nigrum L. Cd hyperaccumulation in soil.

Solanum nigrum L. has a high potential for the remediation of Cd-contaminated soil, and nitrogen fertilizer supply is an effective method to further improve its phytoremediation potential. The soil pot culture experiment was used to explore 4 kinds of nitrogen fertilizers the best fertilizer addition concentrations and their strengthening mechanisms. The results showed that S. nigrum biomass increased with increasing N doses until 800 mg kg-1, where the biomass reached maximum and no longer improved (p < 0.05). However, Cd concentration accumulated by S. nigrum and the extractable Cd concentration in soil did not show a significant decrease (p < 0.05). In this experiment, when N fertilizer was added at 800 mg kg-1 (NH4HCO3, NH4Cl, (NH4)2SO4 and CH4N2O fertilizers), the biomass of the aboveground S. nigrum parts improved to the maximum under (NH4)2SO4 and CH4N2O treatments, i.e. 5.86 g pot-1 and 5.83 g pot-1, increased by 5.92- and 5.89-fold, respectively (p < 0.05), compared to the controls without N fertilizers addition. At the same time, Cd phytoaccumulation in plants was elevated to 128.40 µg pot-1 and 129.14 µg pot-1, increased by 6.20- and 6.24-fold, respectively (p < 0.05), compared to control with no fertilizer added. The results of this experiment demonstrated that Cd phytoextraction capacity (µg pot-1) was the strongest under (NH4)2SO4 and CH4N2O treatments at N content of 800 mg kg-1, when plant nutrient recovery reached the maximum, and these 2 types of nitrogen fertilizers could be utilized to remediate Cd-contaminated soil in field experiments or even in practice.

Selenium spiked in soil promoted zinc accumulation of Chinese cabbage and improved its antioxidant system and lipid peroxidation.

Selenium (Se) and zinc (Zn) are necessary mineral nutrients for human body but millions of people have an inadequate intake of them, and eat food enriched with Se and Zn may minimize these problems. Chinese cabbage is an important food in people's daily life. The aim of this study was to evaluate the effects of single Se, Zn and their combination treatment in soil on their accumulation, antioxidant system and lipid peroxidation in roots and leaves of Chinese cabbage using soil pot culture experiment. When 0.5 mg kg-1 Se +30 mg kg-1 Zn and 1.0 mg kg-1 Se +30 mg kg-1 Zn were spiked in soils, Zn concentrations in roots and leaves of Chinese cabbage were significantly increased (p < 0.05) by 20.2%, 37.8% and 17.9%, 34.1% respectively compared to the treatment of 30 mg kg-1 Zn added, and the latter was significantly higher (p < 0.05) than that of former, indicating Se significantly promoted Zn accumulation. Almost all physiological indexes including POD, SOD, CAT, APX, GR, Chlorophyll a, Chlorophyll b, Carotenoids, MDA and Free proline in the treatments of Se or Zn spiked were significantly improved (p < 0.05) or basically unaffected compared to the control without Se or Zn added. The biomass change trends were similar with these indexes either. These results showed that the addition in soil of Se and Zn significantly increased their accumulation in Chinese cabbage without affected its formal growth. Particularly, the addition of Se promoted Zn accumulation. The conclusions were more important reference for the production practice of cash crop enriched of Se and Zn either.

"Expression of genes encoding protein disulfide isomerase (PDI) in cultivars and lines of common wheat with different baking quality of flour".

BACKGROUND: The subject of this research was to investigate the level of expression of genes encoding protein disulfide isomerase (PDI) in cultivars and lines of wheat with different baking value of flour. PDI plays a key role in the formation of disulfide bonds in newly formed proteins. Each of cultivars and lines had a specific set of high molecular weight glutenin subunits (HMW-GS). Based on the presence of individual subunits, the potential baking value is predicted. Sometimes this value is not confirmed during technological analysis. Since there are cases where flour has a better or worse value than expected on the basis of the genotype, the expression of PDI genes was considered as a potential cause for discrepancies mentioned. RESULTS: Analysis focused on three stages of grain development. The expression level of PDI genes was compared between wheat cultivars and lines with different genotype-phenotype combinations, which means diversified sets of HMW-GS combined with diversified qualitative classification. The highest expression level of PDI was noticed at early stage of grain development, which is consistent with the function of PDI. The expression level was evaluated by the real-time PCR technique. CONCLUSION: Results obtained in this work did not allow for a clear statement of decisive significance of PDI in the context of shaping the final baking value. The results of this work contribute to an ever more in-depth understanding of the mechanisms governing baking value, and thus to the progress of the selection of new varieties with more beneficial properties.

Genetic Variation of Salmo trutta L. Populations from the Catchment Areas of the Rega, Parseta and Wieprza Rivers Evaluated by RAPD and SSR Markers.

By using simple sequence repeats (SSR) and random amplification of polymorphic DNA (RAPD) markers, the genetic variability of three Salmo trutta L. populations from three rivers, the Wieprza, the Rega and the Parseta, was determined. The investigated populations showed a high level of genetic variability. Microsatellites showed that observed heterozygosity (Ho) was higher than the expected heterozygosity (He), with most heterozygotes found in the population from the Parseta river and the fewest in the Wieprza population. The F(IS) coefficient in all investigated populations of the sea trout indicate a high excess of heterozygotes. The highest genetic differentiation was observed between the sea trout from the Rega river and those from the Wieprza (0.366). The obtained results based on microsatellite and RAPD analysis showed that the investigated populations formed two groups. The first group consisted of the sea trout populations from the Wieprza and the Parseta rives, while the second group was formed solely by the Rega river population.

EPAS1 gene variants are associated with sprint/power athletic performance in two cohorts of European athletes.

BACKGROUND: The endothelial PAS domain protein 1 (EPAS1) activates genes that are involved in erythropoiesis and angiogenesis, thus favoring a better delivery of oxygen to the tissues and is a plausible candidate to influence athletic performance. Using innovative statistical methods we compared genotype distributions and interactions of EPAS1 SNPs rs1867785, rs11689011, rs895436, rs4035887 and rs1867782 between sprint/power athletes (n=338), endurance athletes (n=254), and controls (603) in Polish and Russian samples. We also examined the association between these SNPs and the athletes' competition level ('elite' and 'sub-elite' level). Genotyping was performed by either Real-Time PCR or by Single-Base Extension (SBE) method. RESULTS: In the pooled cohort of Polish and Russian athletes, 1) rs1867785 was associated with sprint/power athletic status; the AA genotype in rs1867785 was underrepresented in the sprint/power athletes, 2) rs11689011 was also associated with sprint/power athletic status; the TT genotype in rs11689011 was underrepresented sprint/power athletes, and 3) the interaction between rs1867785, rs11689011, and rs4035887 was associated with sprint/power athletic performance; the combinations of the AA genotype in rs4035887 with either the AG or GG genotypes in rs1867785, or with the CT or CC genotypes in rs11689011, were underrepresented in two cohorts of sprint/power athletes. CONCLUSIONS: Based on the unique statistical model rs1867785/rs11689011 are strong predictors of sprint/power athletic status, and the interaction between rs1867785, rs11689011, and rs4035887 might contribute to success in sprint/power athletic performance.

The effect of exogenous plant growth regulators on elevated Cd phytoremediation by Solanum nigrum L. in contaminated soil.

Maximizing amendment potential is an emphasis in the HM-contaminated field of phytoremediation by hyperaccumulators due to the low bioavailability of HMs in soils and small biomass yields of plants. This study investigated the influence of different types and concentrations of plant growth regulators on Cd phytoremediation by Solanum nigrum in contaminated soil. Our conclusions showed that the shoot Cd extractions (µg plant-1) and the root and shoot biomasses at all the treatments remarkedly increased compared with that of the CK (p < 0.05), while the Cd concentrations at root and aboveground parts by S. nigrum, the extractable Cd concentrations, and pH value of soils did not change significantly compared with the CK (p < 0.05). Furthermore, correlation analysis showed that the shoot Cd phytoaccumulation and the root and aboveground biomasses of S. nigrum were particularly dependent upon the application of CTK and GA3 concentration gradient (p < 0.05). Moreover, some related physicochemical indexes were determined for supervising the growth conditions of plants, and these results pointed out that after exogenous PGRs treatments, the chlorophyll content and antioxidative enzymes POD and SOD activities in vivo of plants clearly advanced, while the H2O2 and MDA contents and CAT apparently declined. These consequence demonstrated that the exogenous PGR addition prominently reinforced the Cd phytoextraction capacity of S. nigrum in contaminated soil by stimulating plant growth and increasing shoot yields.

Effects of copper, and aluminium in ionic, and nanoparticulate form on growth rate and gene expression of Setaria italica seedlings.

This study aims to determine the effects of copper, copper oxide nanoparticles, aluminium, and aluminium oxide nanoparticles on the growth rate and expression of ACT-1, CDPK, LIP, NFC, P5CR, P5CS, GR, and SiZIP1 genes in five days old seedling of Setaria italica ssp. maxima, cultivated in hydroponic culture. Depending on their concentration (ranging from 0.1 to 1.8 mg L-1), all tested substances had both stimulating and inhibiting effects on the growth rate of the seedlings. Copper and copper oxide-NPs had generally a stimulating effect whereas aluminium and aluminium oxide-NPs at first had a positive effect but in higher concentrations they inhibited the growth. Treating the seedlings with 0.4 mg L-1 of each tested toxicant was mostly stimulating to the expression of the genes and reduced the differences between the transcript levels of the coleoptiles and roots. Increasing concentrations of the tested substances had both stimulating and inhibiting effects on the expression levels of the genes. The highest expression levels were usually noted at concentrations between 0.4 and 1.0 mg/L of each metal and metal nanoparticle, except for SiZIP1, which had the highest transcript amount at 1.6 mg L-1 of Cu2+ and at 0.1-0.8 mg L-1 of CuO-NPs, and LIP and GR from the seedling treated with Al2O3-NPs at concentrations of 0.1 and 1.6 mg L-1, respectively.

High-efficiency combination washing agents with eco-friendliness simultaneously removing Cd, Cu and Ni from soil of e-waste recycling site: A lab-scale experiment.

Soil washing technology plays an important role in the removal of heavy metals, and the efficacy of this process depends on the washing agent used. Due to the difficulty in treating soils contaminated by multiple heavy metals, there is still a need for further exploration of efficient washing agents with low environmental impact. Although single washing agents, such as chelators, can also effectively remove heavy metals from soil, combining efficient washing agents and determining their optimal washing conditions can effectively improve their removal efficiency for multiple heavy metals in soil simultaneously. Based on the previous research, the present study was carried out to combine different types of washing agents to remediate contaminated soils at a commonly e-waste recycling site. The objectives were to investigate their efficient washing conditions and assess the impact of the washing process on the speciation distribution and pollution level associated with heavy metals in soil. The results showed that the combination of HEDP (1-hydroxyethylidene-1,1-diphosphonic acid) and FeCl3 at a ratio of 6:4 exhibited the most effective removal of Cd, Cu and Ni from the contaminated soil at an e-waste recycling site. Under optimal washing conditions, with a soil-to-liquid ratio of 1:20 and a washing time of 48 h, the removal rates of Cd, Cu and Ni were 96.72%, 69.91% and 76.08%, respectively. It needed to be emphasized that the combination washing agents were able to remove most of the acid-soluble, reducible and oxidizable fractions of heavy metals, and even the removal rates of the stable residual fraction (e.g., of Cd) was at a relatively high level. In addition, the washing process significantly reduced the pollution level associated with heavy metals in soil. This study aid in the development of combined efficient washing agents and explores optimal washing strategies for the remediation of Cd, Cu, and Ni-contaminated soil at e-waste recycling sites. The findings may play a role in enhancing the remediation capabilities for soils contaminated with multiple heavy metals, due to its characteristics of and high-efficiency and environmental friendliness.

Effects of combined microplastics and heavy metals pollution on terrestrial plants and rhizosphere environment: A review.

Microplastics (MPs) can enter the soil environment through industry, agricultural production and daily life sources. Their interaction with heavy metals (HMs) poses a significant threat to a variety of terrestrial ecosystems, including agricultural ones, thereby affecting crop quality and threatening human health. This review initially addresses the impact of single and combined contamination with MPs and HMs on soil environment, including changes in soil physicochemical properties, microbial community structure and diversity, fertility, enzyme activity and resistance genes, as well as alterations in heavy metal speciation. The article further explores the effects of this pollution on the growth characteristics of terrestrial plants, such as plant biomass, antioxidant systems, metabolites and photosynthesis. In general, the combined contaminants tend to significantly affect soil environment and terrestrial plant growth, i.e., the impact of combined contaminants on plants weight ranged from -87.5% to 4.55%. Similarities and differences in contamination impact levels stem from the variations in contaminant types, sizes and doses of contaminants and the specific plant growth environments. In addition, MPs can not only infiltrate plants directly, but also significantly affect the accumulation of HMs in terrestrial plants. The heavy metals concentration in plants under the treatment of MPs were 70.26%-36.80%. The co-occurrence of these two pollution types can pose a serious threat to crop productivity and safety. Finally, this study proposes suggestions for future research aiming to address current gaps in knowledge, raises awareness about the impact of combined MPs + HMs pollution on plant growth and eco-environmental security.

A comparative study on cadmium tolerance and applicability of two Solanum lycopersicum L. cultivars.

Solanum lycopersicum L. can be classified into low Cd-accumulating and high Cd-accumulating types based on their accumulation characteristics of cadmium (Cd). There are many common S. lycopersicum varieties available in the market, but their specific Cd tolerance and enrichment abilities are not well understood. This article uses two S. lycopersicum cultivars, Yellow Cherry and Yellow Pearl, as experimental materials. The experimental method of soil pot planting was adopted, and Cd concentrations in the soil were added at 0, 0.6, 1.5, 2.5, 5, and 10 mg/kg. The changes in Cd content, biomass, photosynthetic pigment content, and photosynthetic parameters of the two S. lycopersicum cultivars were analyzed to screen for low-accumulation S. lycopersicum cultivars. The results showed that S. lycopersicum are Cd-sensitive plants. The Cd accumulation, photosynthetic parameters, and other basic indicators of Yellow Cherry basically showed significant differences when the soil Cd concentration was 0.6 mg/kg, and the biomass showed significant differences when the soil Cd concentration was 1.5 mg/kg. Except for the Cd accumulation in the roots and leaves of Yellow Pearl, which showed significant differences at a soil Cd concentration of 0.6 mg/kg, the other indicators basically showed significant differences when the soil Cd concentration was 1.5 mg/kg. When the soil Cd concentration was 0.6 mg/kg, the Cd accumulation in the fruit of Yellow Pearl was 0.04 mg/kg, making it a low-accumulation S. lycopersicum variety suitable for promoting cultivation in Cd-contaminated soil at 0.6 mg/kg. In conclusion, the Cd accumulation in the fruit of Yellow Pearl is significantly lower than that of Yellow Cherry and even below the Cd limit value for fresh vegetables specified in GB2762-2017. Therefore, Yellow Pearl can be grown as edible crops in soils with Cd concentrations ≤0.6 mg/kg. Furthermore, Yellow Cherry demonstrate strong Cd tolerance and can be used for the remediation of Cd-contaminated soils.

Cadmium phytoextraction efficiency of hyperaccumulator as affected by harvest stage in three continuous years.

Phytoremediation which mainly using hyperaccumulator is a very popular and environmental-friendly clean method. Long term continuous test is very important due to its low remediation efficiency in a growth period. Cd hyperaccumulator Rorippa globosa (Turcz.) Thell. Was used to explore the effect of two remediation modes (harvests at flowering and maturity stages) on the continuous remediation efficiency in a 3-year experiment using pot experiment with real Cd contaminated soil. The results showed that the biomass in maturity-harvest treatments was 1.12 times of that in flowering-harvest treatments due to the short vegetation time. Shoot Cd concentrations in the flowering-harvest treatments were on average 15.4% lower compared to the maturity-harvest treatments either. However, the Cd phytoextraction efficiency (PE) in the flowering-harvest treatments was 13.8% higher compared to the harvests at the maturity stage due to the growth cycle of R. globosa harvested at the flowering was 34.5% of shorter compared to those in the maturity harvest treatments. After three consecutive years of R. globosa phytoextraction, the concentration of extractable Cd decreased on average by 28.7% and corresponding PEs lower either. It was suggested that cultivation modes of R. globosa and low-accumulation crop rotation, or three times flowering harvests of R. globosa per year seemed to be a good choice in practical solution.

Toxicity of emerging contaminant antibiotics in soil to Capsicum annuum L. growth and their effects on it accumulating copper.

Antibiotics are a kind of emerging contaminant in soil. Tetracycline (TC) and oxytetracycline (OTC) in soil are often detected, even with very high concentration in the soils of facility agriculture due to their good effect, low price and large usage. Copper (Cu) is common heavy metal pollutant in soil. The toxicity roles of TC, OTC and/or Cu in soil on a commonly consumed vegetable Capsicum annuum L. and its Cu accumulation were not clear till now. The results of pot experiment showed that the TC or OTC added in soil alone didn't produce poison effects for C. annuum after 6 weeks and 12 weeks growth reflected by some physiological index like SOD, CAT and APX activities changes, while the biomass changes affirmed them either. Cu contaminated soil significantly inhibited the growth of C. annuum. Furthermore, combined pollution of Cu with TC or OTC was with more serious suppression of C. annuum growth. The suppression role of OTC was heavier than TC in Cu and TC or OTC contaminated soil. Such phenomenon was relevant with the role of TC or OTC increased Cu concentration in C. annuum. The improvement role of TC or OTC on Cu accumulation in C. annuum caused by the increased extractable Cu concentration in soil. The study demonstrated that TC or OTC added in soil alone was without any toxicity to C. annuum. But they may aggravate the hurt of C. annuum caused by Cu through increased its accumulation from soil. Thus, such combine pollution should be avoided in safe agricultural product.

The effects of salinity and pH variation on hyperaccumulator Bidens pilosa L. accumulating cadmium with dynamic and real-time uptake of Cd2+ influx around its root apexes.

Bidens pilosa L. has been confirmed to be a potential Cd hyperaccumulator by some researchers, but the dynamic and real-time uptake of Cd2+ influx by B. pilosa root apexes was a conundrum up to now. The aim of our study was to investigate the effects of salinity and pH variations on the characteristics of Cd2+ influx around the root apexes of B. pilosa. The tested seedlings of B. pilosa were obtained by sand culture experiments in a greenhouse after 1 month from germination, and the Cd2+ influxes from the root apex of B. pilosa under Cd treatments with different salinity and pH levels were determined with application of non-invasive micro-test technology (NMT). The results showed that Cd2+ influxes at 300 µm from the root tips decreased under Cd treatments with 5 mM and 10 mM NaCl, as compared to Cd stress alone. However, Cd treatments with 2.5 mM NaCl had little effect on the net Cd2+ influxes, as compared to Cd treatments alone. Importantly, Cd treatments at pH = 4.0 markedly increased Cd2+ influxes in roots, and Cd treatment at pH = 7.0 had no significant effect on the net Cd2+ influxes compared to Cd treatments at pH = 5.5. Results also showed that Cd treatments with 10 mM NaCl significantly decreased concentrations of chlorophyll (Chl) a and b in leaves and root vigor of B. pilosa relative to Cd treatments alone, while there were no significant differences between Cd treatments with 2.5 mM NaCl and Cd treatments alone. But root vigor was inhibited significantly under Cd treatments with 5 mM and 10 mM NaCl. A significant increase of root vigor was observed in Cd treatments at pH = 4.0, as compared to pH = 5.5. The Cd treatments with high and medium concentrations of NaCl inhibited the uptake of Cd by B. pilosa roots and affected the Chl and root vigor further. But the Cd treatments at pH = 4.0 could promote the Cd uptake and root vigor. Our results revealed the uptake mechanisms of B. pilosa as a potential phytoremediator under different salinity and pH levels combined with Cd contamination and provided a new idea for screening ideal hyperaccumulator and constructing evaluation system.