Pollution accident of nonferrous metallurgy industry often lead to serious heavy metal pollution of the surrounding soil.Phytoremediation of contaminated soil is an environmental and sustainable technology,and soil na...Pollution accident of nonferrous metallurgy industry often lead to serious heavy metal pollution of the surrounding soil.Phytoremediation of contaminated soil is an environmental and sustainable technology,and soil native microorganisms in the process of phytoremediation also participate in the remediation of heavy metals.However,the effects of high concentrations of multiple heavy metals(HCMHMs)on plants and native soil microorganisms remain uncertain.Thus,further clarification of themechanism of phytoremediation of HCMHMs soil by plants and native soil microorganisms is required.Using the plant Sedum alfredii(S.alfredii)to restore HCMHM-contaminated soil,we further explored the mechanism of S.alfredii and native soil microorganisms in the remediation of HCMHM soils.The results showed that(i)S.alfredii can promote heavy metals from non-rhizosphere soil to rhizosphere soil,which is conducive to the effect of plants on heavy metals.In addition,it can also enrich the absorbed heavy metals in its roots and leaves;(ii)native soil bacteria can increase the abundance of signal molecule-synthesizing enzymes,such as trpE,trpG,bjaI,rpfF,ACSL,and yidC,and promote the expression of the pathway that converts serine to cysteine,then synthesize substances to chelate heavy metals.In addition,we speculated that genes such as K19703,K07891,K09711,K19703,K07891,and K09711 in native bacteria may be involved in the stabilization or absorption of heavy metals.The results provide scientific basis for S.alfredii to remediate heavy metals contaminated soils,and confirm the potential of phytoremediation of HCMHM contaminated soil.展开更多
Two new species of Crassulaceae,Sedum baiwanense Yan S.Huang&Q.Fan and S.nankunshanense Yan S.Huang&Q.Fan,from Guangdong,China,are described and illustrated here.Phylogenetic analysis based on the internal tra...Two new species of Crassulaceae,Sedum baiwanense Yan S.Huang&Q.Fan and S.nankunshanense Yan S.Huang&Q.Fan,from Guangdong,China,are described and illustrated here.Phylogenetic analysis based on the internal transcribed spacer(ITS)region of nrDNA suggests that the two new species belong to Acre Clade,and are relative to S.subtile Miq.,S.tianmushanense Y.C.Ho&F.Chai,and S.jiulungshanense Y.C.Ho with high support values(node posterior probabilities=1).With high morphologically differences,we can easily distinguish species in this monophyletic group.展开更多
To investigate the response mechanisms of Sedum plumbizincicola under low-temperature stress,phenotypic traits and physiological parameters including superoxide dismutase(SOD)activity,peroxidase(POD)activity,and malon...To investigate the response mechanisms of Sedum plumbizincicola under low-temperature stress,phenotypic traits and physiological parameters including superoxide dismutase(SOD)activity,peroxidase(POD)activity,and malondialdehyde(MDA)content were examined following 6-hour treatments at 22(control),10,and-2℃.Transcriptome analysis was subsequently conducted.The results showed that low-temperature stress significantly enhanced antioxidant enzyme activities(SOD and POD),along with osmotic adjustment-related indicators such as MDA content,soluble sugar and protein content,and relative electrolytic conductivity.After quality control and optimization of the transcriptome data,a total of 78803 unigenes were obtained,with an average length of 871.13 bp and an N50 of 1510 bp.Compared with the control,8391 and 10730 differentially expressed genes(DEGs)were identified under 10 and-2℃treatments,respectively.Gene Ontology(GO)enrichment analysis indicated that these DEGs were mainly involved in responses to abiotic stimuli including temperature,DNA-binding transcription factor activity,and amino acid metabolic processes.In S.plumbizincicola,the activation of flavonoid biosynthesis and MAPK signaling pathways likely played a critical role in low-temperature response.Under low-temperature stress,the plant enhanced its stress resistance by significantly elevating antioxidant enzyme activities and accumulating osmolytes.Concurrently,transcriptomic analysis indicated that metabolic pathways such as flavonoid biosynthesis,MAPK signaling,nitrogen metabolism,and plant hormone signal transduction were crucial for S.plumbizincicola’s adaptation to low-temperature stress.展开更多
Sedum alfredii Hance has been identified as a new Zn-hyperaccumulator native to China. In this study, responses and metal accumulation of S alfredii were examined under Zn/Cd complex polluted conditions. The results s...Sedum alfredii Hance has been identified as a new Zn-hyperaccumulator native to China. In this study, responses and metal accumulation of S alfredii were examined under Zn/Cd complex polluted conditions. The results showed that optimal growth of S alfredii in terms of the maximum dry matter yield was observed at Zn/Cd complex level of 500/100 mumol/L. Plant cadmium (Cd) or zinc (Zn) concentrations increased with increasing Cd or Zn supply. During the 20 d treatment, the highest Cd concentration in the leaves reached 12.1 g/kg at Zn/Cd level of 50/400 mumol/L and that of Zn in the stems was 23.2 g/kg at Zn/Cd level of 1000/50 mumol/L. The distribution of Cd in different plant parts decreased in the order: leaf > stem greater than or equal to root, whereas that of Zn was: stem > leaf greater than or equal to root. The accumulation of Cd and Zn in the shoots and roots of S. alfredii increased with the increasing of Zn/Cd supply levels, peaked at Zn/Cd levels of 250/400 and 500/100 mumol/L, respectively. The highest Cd and Zn uptake by the shoots was approximately 5 and 11 mg/plant, and was over 20 and 10 times higher than those in the roots, respectively. Zn supply at levels less than or equal to 500 mumol/L increased plant Cd concentrations, whereas high Zn supply decreased root Cd but did not affect leaf Cd concentrations in S alfredii Low Cd supply increased Zn concentration in the leaves, but Cd supply higher than 50 mumol/L considerably reduced root Zn concentrations, especially at low Zn level. These results indicate that S. alfredii can tolerate high Zn/Cd complex levels and has an extraordinary ability to hyperaccumulate not only Zn but also Cd. It could provide a new valuable plant material for understanding the mechanisms responsible for co-hyperaccumulation of Zn and Cd as well as for phytoremediation of the Cd/Zn complex polluted soils.展开更多
Four species of Sedum L. were grown in nutrient solution for the comparison of their Zn uptake and accumulation. S. alfredii Hance showed much greater tolerance to Zn than the other three species. Shoot and root yield...Four species of Sedum L. were grown in nutrient solution for the comparison of their Zn uptake and accumulation. S. alfredii Hance showed much greater tolerance to Zn than the other three species. Shoot and root yields of S. sarmentosum Bunge, S. bulbiferum Makino, and S. emarginatum Migo decreased with increasing Zn concentration in the solution, while shoot and root yields of S. alfredii increased when Zn concentration was ≤80 mg·L -1. At 80 mg·L -1 Zn, Zn concentration in shoots of S. alfredii reached 19.09 mg·g -1. S. alfredii was also more efficient in Zn translocation from roots to shoots, while Zn concentration in shoots was much higher than in roots. However, this was not the case for the other three species. The results showed that S. alfredii is a Zn hyperaccumulator and could be useful for the phytoremediation of Zn-contaminated soils.展开更多
hi a survey of plant population, Sedum alfredii Hance, a new lead (Pb)-tolerant and lead (Pb)accumulating ecotype, was found in an old Pb/Zn mining area in Zhejiang Province of China. The growth and Pb content of plan...hi a survey of plant population, Sedum alfredii Hance, a new lead (Pb)-tolerant and lead (Pb)accumulating ecotype, was found in an old Pb/Zn mining area in Zhejiang Province of China. The growth and Pb content of plant ecotypes being able to and unable to accumulate Pb were studied by hydroponic culture with different concentrations of Pb(NO3)(2). Growth of shoots of accumulating ecotype was not affected by Ph treatments up to 320 mg/L, whereas that of non-accumulating ecotype was inhibited in all Ph treatments. The Ph concentrations in the roots and shoots of accumulating ecotype increased with increasing of Pb level in the nutrient solution. The maximum Ph concentrations in the shoots and roots of accumulating ecotype were 514 mg/kg and 13 922 mg/kg, 2.27 times and 2.62 times as much as that of non-accumulating ecotype, respectively. The highest rate of Pb accumulation of accumulating ecotype was 8.62 mug/plant/d, 7.16 times as much as that of non-accumulating ecotype. Due to its fast growth rate and high Pb-accumulating ability, from a phytoremediation perspective, accumulating ecotype of S. alfredii is a potential plant species for Pb removal from contaminated soils.展开更多
Sedum aizoon L.（SA） has been widely used for treatment of various hemorrhages, insomnia, pain and trauma？ however, its anti-inflammatory activity is unknown. In this study, we firstly investigated the anti--inflamm...Sedum aizoon L.（SA） has been widely used for treatment of various hemorrhages, insomnia, pain and trauma？ however, its anti-inflammatory activity is unknown. In this study, we firstly investigated the anti--inflammatory activity of SA extracts by petroleum ether（PE）, ethyl acetate（EtOAc）, and H2O in LPS-stimulated RAW 264.7 cells. Results showed that the EtOAc extract rich in phenolics and flavonoids significantly inhibited LPS-induced NO, TNF--α, and IL-6 production in RAW 264.7 cells（P0.01）, suggesting that this extract possessed potent anti--inflammatory activity. The phytochemical profile of the effective extract was subsequently analyzed by HPLC fingerprint with 11 standards. The results indicated that gallic acid, protocatechuic acid, p--hydroxybenzoic acid, ethyl gallate, iriflophene, 5,7-dihydroxy chromone, quercitrin, quercetin, luteolin, kaempferol, and isorhamnetin were present in this extract, which might contribute to its anti-inflammatory activity. Thus, the Et -OAc extract of SA showed anti-inflammatory activity and could be used as a potential natural anti--inflammatory agent.展开更多
The mining ecotype Sedum alfredii Hance could tolerate and grow normally in a nutritive solution containing cadmium (Cd) as high as 400 mumol/L. Under such a high Cd concentration, the subcellular accumulation of Cd i...The mining ecotype Sedum alfredii Hance could tolerate and grow normally in a nutritive solution containing cadmium (Cd) as high as 400 mumol/L. Under such a high Cd concentration, the subcellular accumulation of Cd in root, stem and leaf of this plant was found to be the highest in the cell wall, less in the soluble fraction and lowest in the cell organs. The mode of subcellular distribution of Cd in the mining ecotype S. alfredii was similar to other hyper accumulators of heavy metals, in which Cd was distributed more in the aerial part of plant. The results suggest that the mining ecotype S. alfredii is a new species of Cd hyperaccumulator.展开更多
The switch from C-3 to CAM pathway was induced by water stress in a C-3/CAM intermediate plant Sedum spectabile Boreau. Typical CAM criteria were observed upon 15 d of withholding water. Leaf delta(13)C value (-%) and...The switch from C-3 to CAM pathway was induced by water stress in a C-3/CAM intermediate plant Sedum spectabile Boreau. Typical CAM criteria were observed upon 15 d of withholding water. Leaf delta(13)C value (-%) and water content showed a linear correlation fashion. Chlorophyll fluorescence parameters and antioxidative capacity were altered by water stress. Phi(PSII) and q(P) were reduced by 50% and 34% of the control, respectively, while NPQ rose ca. 180%. SOD activity and ability to scavenge DPPH. free radical went down but membrane permeability changed slightly. However, when an additional photooxidation by MV with high PPFD was carried out with leaf discs from watered (C-3 mode) and drought plants (CAM mode), q(P) and Phi(PSII) in leaves at induced CAM mode stage continuously decreased to a very low level. High 1 - q(P) value (0.86) and 1 - q(P)/NPQ ratio (>1) indicated the presence of high reduction state and unbalance of light energy budget. Together with the marked loss of membrane integral, it was evidenced that photooxidative damage was more serious in the induced CAM mode than in the C-3 mode. No advantage of photooxidation tolerance was found at the induced CAM expression stage of the facultative CAM plant, as compared with its C-3 mode stage, and also with the constitutive CAM plants reported previously. The differences in photooxidation sensitivity between the inducible CAM expressing plant and the constitutive CAM plant were discussed.展开更多
Phytoremediation is a cost-effective and environment-friendly strategy for decontaminating heavy-metal-contaminated soil.However, the practical use of phytoremediation is constrained by the low biomass of plants and l...Phytoremediation is a cost-effective and environment-friendly strategy for decontaminating heavy-metal-contaminated soil.However, the practical use of phytoremediation is constrained by the low biomass of plants and low bioavailability of heavy metals in soil.A pot experiment was conducted to investigate the effects of the metal chelator ethylenediaminetetraacetic acid(EDTA) and EDTA in combination with plant growth-promoting rhizobacteria(Burkholderia sp.D54 or Burkholderia sp.D416) on the growth and metal uptake of the hyperaccumulator Sedum alfredii Hance.According to the results, EDTA application decreased shoot and root biomass by 50% and 43%, respectively.The soil respiration and Cd,Pb, Zn uptake were depressed, while the photosynthetic rate, glutathione and phytochelatin(PC) contents were increased by EDTA application.Interestingly, Burkholderia sp.D54 and Burkholderia sp.D416 inoculation significantly relieved the inhibitory effects of EDTA on plant growth and soil respiration.Compared with the control, EDTA + D416 treatment increased the Cd concentration in shoots and decreased the Pb concentration in shoots and roots, but did not change the Zn concentration in S.alfredii plants.Furthermore,EDTA, EDTA + D54 and EDTA + D416 application increased the cysteine and PC contents in S.alfredii(p < 0.05);among all tested PCs, the most abundant species was PC2, and compared with the control, the PC2 content was increased by 371.0%, 1158.6% and 815.6%,respectively.These results will provide some insights into the practical use of EDTA and PGPR in the phytoremediation of heavy-metal-contaminated soil by S.alfredii.展开更多
Improving the efficacy of phytoextraction is critical for its successful application in metal contaminated soils. Mineral nutrition affects plant growth and metal absorption and subsequently the accumulation of heavy ...Improving the efficacy of phytoextraction is critical for its successful application in metal contaminated soils. Mineral nutrition affects plant growth and metal absorption and subsequently the accumulation of heavy metal through hyper-accumulator plants. This study assessed the effects of di-hydrogen phosphates （KH2PO4, Ca（H2PO4）2, NaH2PO4 and NH4H2PO4） application at three levels （22, 88 and 352 mg P/kg soil） on Sedum alfredii growth and metal uptake by three consecutive harvests on aged and Zn/Cd combined contaminated paddy soil. The addition of phosphates （P） significantly increased the amount of Zn taken up by S. alfredii due to increased shoot Zn concentration and dry matter yield （DMY） （P 〈 0.05）. The highest phytoextraction of Zn and Cd was observed in KH2PO4 and NH4H2PO4 treatment at 352 mg P/kg soil. The amount of Zn removed by phytoextraction increased in the order of 1st clipping 〈 2nd clipping 〈 3rd clipping, and for Cd extraction the order was 2nd clipping 〈 1st clipping 〈 3rd clipping. These results indicate that the application of P fertilizers coupled with multiple cuttings can enhance the removal of Zn and Cd from contaminated soils by S. alfredii, thus shortening the time needed for accomplishing remediation goals.展开更多
The elucidation of a natural strategy for metal hyperaccumulation enables the rational design of technologies for the clean-up of metal-contaminated soils.Organic acid has been suggested to be involved in toxic metall...The elucidation of a natural strategy for metal hyperaccumulation enables the rational design of technologies for the clean-up of metal-contaminated soils.Organic acid has been suggested to be involved in toxic metallic element tolerance,translocation,and accumulation in plants.The impact of exogenous organic acids on cadmium(Cd) uptake and translocation in the zinc(Zn)/Cd co-hyperaccumulator Sedum alfredii was investigated in the present study.By the addition of organic acids,short-term(2 h) root uptake of 109 Cd increased significantly,and higher 109 Cd contents in roots and shoots were noted 24 h after uptake,when compared to controls.About 85% of the 109 Cd taken up was distributed to the shoots in plants with citric acid(CA) treatments,as compared with 75% within controls.No such effect was observed for tartaric acid(TA).Reduced growth under Cd stress was significantly alleviated by low CA.Long-term application of the two organic acids both resulted in elevated Cd in plants,but the effects varied with exposure time and levels.The results imply that CA may be involved in the processes of Cd uptake,translocation and tolerance in S.alfredii,whereas the impact of TA is mainly on the root uptake of Cd.展开更多
Sedum alfredii Hance is a cadmium(Cd)/zinc(Zn)hyperaccumulator native to China.However,its relatively low biomass restricted the large-scale application for heavy metal contamination remediation.The chromosome set dou...Sedum alfredii Hance is a cadmium(Cd)/zinc(Zn)hyperaccumulator native to China.However,its relatively low biomass restricted the large-scale application for heavy metal contamination remediation.The chromosome set doubling of S.alfredii in vitro was achieved by 0.1%–0.2%(W/V)colchicine treatment.The plant DNA ploidy was analyzed by flow cytometry and chromosome set doubling plants(CSD)were identified based on the obvious different sharp peak.A tissue culture experiment with different Cd treated levels and a field trial with natural polluted mined soil were conducted to study the effects of chromosome doubling on plant biomass and Cd accumulation in shoots.The results suggested that S.alfredii is a mixoploid.Compared with the wild type plants(WT),CSD exhibited typical"gigas"characteristics in morphology including stem thickness,root hair production,number of leaves and size of stoma guard cell.Fresh weight and dry weight of CSD were increased to 1.62–2.03-fold and 2.26–3.25-fold of WT.And Cd content of CSD showed a17.49%–42.82%increase and 59%increase under tissue culture and field condition,accordingly.In addition,the TF and in BCF of CSD were 2.37-and 1.59-fold of WT,respectively.These results proved that it is feasible to promote phytoextraction efficiency of S.alfredii in Cd contaminated soils through chromosomal engineering,which provides a novel approach for hyperaccumulator application in phytoremediation.展开更多
Combined pollution of 1,1,1-trichloro-2,2-bis （4-chlorophenyl） ethane （DDT） and cadmium （Cd） in agricultural soils is of great concern because they present serious risk to food security and human health.In order...Combined pollution of 1,1,1-trichloro-2,2-bis （4-chlorophenyl） ethane （DDT） and cadmium （Cd） in agricultural soils is of great concern because they present serious risk to food security and human health.In order to develop a cost-effective and safe method for the removal of DDTs and Cd in soil,combined remediation of DDTs and Cd in soil by Sphingobacterium sp.D-6 and the hyperaccumulator,Sedum alfredii Hance was investigated.After treatment for 210 days,the degradation half-lives of DDTs in soils treated by strain D-6 decreased by 8.1% to 68.0% compared with those in the controls.The inoculation of strain D-6 into soil decreased the uptake of DDTs by pak choi and S.alfredii.The shoots/roots ratios of S.alfredii for the Cd accumulation ranged from 12.32 to 21.75.The Cd concentration in soil decreased to 65.8%-71.8% for S.alfredii treatment and 14.1%-58.2% for S.alfredii and strain D-6 combined treatment,respectively,compared with that in the control.The population size of the DDTs-degrading strain,Simpson index （1/D） and soil respiratory rate decreased in the early stage of treatment and then gradually increased,ultimately recovering to or exceeding the initial level.The results indicated that synchronous incorporation of strain D-6 and S.alfredii into soil was found to significantly （p 0.05） enhance the degradation of DDTs in soil and the hyperaccumulation of Cd in S.alfredii.It was concluded that strain D-6 and S.alfredii could be used successfully to control DDTs and Cd in contaminated soil.展开更多
Radiotracer techniques were employed to characterize 65Zn adsorption and desorption in root-cell-wall of hyperac-cumulating ecotype (HE) and non-hyperaccumulating ecotype (NHE) species of Sedum alfredii Hance. The res...Radiotracer techniques were employed to characterize 65Zn adsorption and desorption in root-cell-wall of hyperac-cumulating ecotype (HE) and non-hyperaccumulating ecotype (NHE) species of Sedum alfredii Hance. The results indicated that at the end of a 30 min short time radioisotope loading period, comparable amounts of 65Zn were accumulated in the roots of the two ecotypes Sedum alfredii, whereas 2.1-fold more 65Zn remains in NHE root after 45-min desorption. At the end of 60 min uptake period, no difference of 65Zn accumulation was observed in undesorbed root-cell-wall of Sedum alfredii. However, 3.0-fold more 65Zn accumulated in desorbed root-cell-wall of NHE. Zn2+ binding in root-cell-wall preparations of NHE was greater than that in HE under high Zn2+ concentration. All these results suggested that root-cell-wall of the two ecotypes Sedum alfredii had the same ability to adsorb Zn2+, whereas the desorption characteristics were different, and with most of 65Zn binding on root of HE being available for loading into the xylem, as a result, more 65Zn was translocated to the shoot.展开更多
基金supported by the Fundamental Research Funds for Central PublicWelfare Scientific Research Institutes of China(No.2021-JY-37)the Yellow River Basin Ecological Protection and High-quality Development Joint Study(Phase I)(No.2022-YRUC-01-0202).
文摘Pollution accident of nonferrous metallurgy industry often lead to serious heavy metal pollution of the surrounding soil.Phytoremediation of contaminated soil is an environmental and sustainable technology,and soil native microorganisms in the process of phytoremediation also participate in the remediation of heavy metals.However,the effects of high concentrations of multiple heavy metals(HCMHMs)on plants and native soil microorganisms remain uncertain.Thus,further clarification of themechanism of phytoremediation of HCMHMs soil by plants and native soil microorganisms is required.Using the plant Sedum alfredii(S.alfredii)to restore HCMHM-contaminated soil,we further explored the mechanism of S.alfredii and native soil microorganisms in the remediation of HCMHM soils.The results showed that(i)S.alfredii can promote heavy metals from non-rhizosphere soil to rhizosphere soil,which is conducive to the effect of plants on heavy metals.In addition,it can also enrich the absorbed heavy metals in its roots and leaves;(ii)native soil bacteria can increase the abundance of signal molecule-synthesizing enzymes,such as trpE,trpG,bjaI,rpfF,ACSL,and yidC,and promote the expression of the pathway that converts serine to cysteine,then synthesize substances to chelate heavy metals.In addition,we speculated that genes such as K19703,K07891,K09711,K19703,K07891,and K09711 in native bacteria may be involved in the stabilization or absorption of heavy metals.The results provide scientific basis for S.alfredii to remediate heavy metals contaminated soils,and confirm the potential of phytoremediation of HCMHM contaminated soil.
基金Supported by Forest Ecosystem Monitoring Project of Baiwan Provincial Nature Reserve,Qingxin,Guangdong(QCCG2025-003)Guangdong Provincial EQI Monitoring Project(GPCGD241115FG155F)Preliminary Survey and Monitoring and Conservation of Rare and Endangered Plant Species in Qingyuan Karst Mountain Botanical Garden(HT-99982024-0030)。
文摘Two new species of Crassulaceae,Sedum baiwanense Yan S.Huang&Q.Fan and S.nankunshanense Yan S.Huang&Q.Fan,from Guangdong,China,are described and illustrated here.Phylogenetic analysis based on the internal transcribed spacer(ITS)region of nrDNA suggests that the two new species belong to Acre Clade,and are relative to S.subtile Miq.,S.tianmushanense Y.C.Ho&F.Chai,and S.jiulungshanense Y.C.Ho with high support values(node posterior probabilities=1).With high morphologically differences,we can easily distinguish species in this monophyletic group.
文摘To investigate the response mechanisms of Sedum plumbizincicola under low-temperature stress,phenotypic traits and physiological parameters including superoxide dismutase(SOD)activity,peroxidase(POD)activity,and malondialdehyde(MDA)content were examined following 6-hour treatments at 22(control),10,and-2℃.Transcriptome analysis was subsequently conducted.The results showed that low-temperature stress significantly enhanced antioxidant enzyme activities(SOD and POD),along with osmotic adjustment-related indicators such as MDA content,soluble sugar and protein content,and relative electrolytic conductivity.After quality control and optimization of the transcriptome data,a total of 78803 unigenes were obtained,with an average length of 871.13 bp and an N50 of 1510 bp.Compared with the control,8391 and 10730 differentially expressed genes(DEGs)were identified under 10 and-2℃treatments,respectively.Gene Ontology(GO)enrichment analysis indicated that these DEGs were mainly involved in responses to abiotic stimuli including temperature,DNA-binding transcription factor activity,and amino acid metabolic processes.In S.plumbizincicola,the activation of flavonoid biosynthesis and MAPK signaling pathways likely played a critical role in low-temperature response.Under low-temperature stress,the plant enhanced its stress resistance by significantly elevating antioxidant enzyme activities and accumulating osmolytes.Concurrently,transcriptomic analysis indicated that metabolic pathways such as flavonoid biosynthesis,MAPK signaling,nitrogen metabolism,and plant hormone signal transduction were crucial for S.plumbizincicola’s adaptation to low-temperature stress.
文摘Sedum alfredii Hance has been identified as a new Zn-hyperaccumulator native to China. In this study, responses and metal accumulation of S alfredii were examined under Zn/Cd complex polluted conditions. The results showed that optimal growth of S alfredii in terms of the maximum dry matter yield was observed at Zn/Cd complex level of 500/100 mumol/L. Plant cadmium (Cd) or zinc (Zn) concentrations increased with increasing Cd or Zn supply. During the 20 d treatment, the highest Cd concentration in the leaves reached 12.1 g/kg at Zn/Cd level of 50/400 mumol/L and that of Zn in the stems was 23.2 g/kg at Zn/Cd level of 1000/50 mumol/L. The distribution of Cd in different plant parts decreased in the order: leaf > stem greater than or equal to root, whereas that of Zn was: stem > leaf greater than or equal to root. The accumulation of Cd and Zn in the shoots and roots of S. alfredii increased with the increasing of Zn/Cd supply levels, peaked at Zn/Cd levels of 250/400 and 500/100 mumol/L, respectively. The highest Cd and Zn uptake by the shoots was approximately 5 and 11 mg/plant, and was over 20 and 10 times higher than those in the roots, respectively. Zn supply at levels less than or equal to 500 mumol/L increased plant Cd concentrations, whereas high Zn supply decreased root Cd but did not affect leaf Cd concentrations in S alfredii Low Cd supply increased Zn concentration in the leaves, but Cd supply higher than 50 mumol/L considerably reduced root Zn concentrations, especially at low Zn level. These results indicate that S. alfredii can tolerate high Zn/Cd complex levels and has an extraordinary ability to hyperaccumulate not only Zn but also Cd. It could provide a new valuable plant material for understanding the mechanisms responsible for co-hyperaccumulation of Zn and Cd as well as for phytoremediation of the Cd/Zn complex polluted soils.
文摘Four species of Sedum L. were grown in nutrient solution for the comparison of their Zn uptake and accumulation. S. alfredii Hance showed much greater tolerance to Zn than the other three species. Shoot and root yields of S. sarmentosum Bunge, S. bulbiferum Makino, and S. emarginatum Migo decreased with increasing Zn concentration in the solution, while shoot and root yields of S. alfredii increased when Zn concentration was ≤80 mg·L -1. At 80 mg·L -1 Zn, Zn concentration in shoots of S. alfredii reached 19.09 mg·g -1. S. alfredii was also more efficient in Zn translocation from roots to shoots, while Zn concentration in shoots was much higher than in roots. However, this was not the case for the other three species. The results showed that S. alfredii is a Zn hyperaccumulator and could be useful for the phytoremediation of Zn-contaminated soils.
文摘hi a survey of plant population, Sedum alfredii Hance, a new lead (Pb)-tolerant and lead (Pb)accumulating ecotype, was found in an old Pb/Zn mining area in Zhejiang Province of China. The growth and Pb content of plant ecotypes being able to and unable to accumulate Pb were studied by hydroponic culture with different concentrations of Pb(NO3)(2). Growth of shoots of accumulating ecotype was not affected by Ph treatments up to 320 mg/L, whereas that of non-accumulating ecotype was inhibited in all Ph treatments. The Ph concentrations in the roots and shoots of accumulating ecotype increased with increasing of Pb level in the nutrient solution. The maximum Ph concentrations in the shoots and roots of accumulating ecotype were 514 mg/kg and 13 922 mg/kg, 2.27 times and 2.62 times as much as that of non-accumulating ecotype, respectively. The highest rate of Pb accumulation of accumulating ecotype was 8.62 mug/plant/d, 7.16 times as much as that of non-accumulating ecotype. Due to its fast growth rate and high Pb-accumulating ability, from a phytoremediation perspective, accumulating ecotype of S. alfredii is a potential plant species for Pb removal from contaminated soils.
基金Quality guarantee system of Chinese herbal medicines(Grant No.201507002)Key project of science and technology of Fujian province(Grant No.2014Y0053)youth project of Fujian Provincial Health and Family Planning Commission(Grant No.2015--1--77)
文摘Sedum aizoon L.（SA） has been widely used for treatment of various hemorrhages, insomnia, pain and trauma？ however, its anti-inflammatory activity is unknown. In this study, we firstly investigated the anti--inflammatory activity of SA extracts by petroleum ether（PE）, ethyl acetate（EtOAc）, and H2O in LPS-stimulated RAW 264.7 cells. Results showed that the EtOAc extract rich in phenolics and flavonoids significantly inhibited LPS-induced NO, TNF--α, and IL-6 production in RAW 264.7 cells（P0.01）, suggesting that this extract possessed potent anti--inflammatory activity. The phytochemical profile of the effective extract was subsequently analyzed by HPLC fingerprint with 11 standards. The results indicated that gallic acid, protocatechuic acid, p--hydroxybenzoic acid, ethyl gallate, iriflophene, 5,7-dihydroxy chromone, quercitrin, quercetin, luteolin, kaempferol, and isorhamnetin were present in this extract, which might contribute to its anti-inflammatory activity. Thus, the Et -OAc extract of SA showed anti-inflammatory activity and could be used as a potential natural anti--inflammatory agent.
文摘The mining ecotype Sedum alfredii Hance could tolerate and grow normally in a nutritive solution containing cadmium (Cd) as high as 400 mumol/L. Under such a high Cd concentration, the subcellular accumulation of Cd in root, stem and leaf of this plant was found to be the highest in the cell wall, less in the soluble fraction and lowest in the cell organs. The mode of subcellular distribution of Cd in the mining ecotype S. alfredii was similar to other hyper accumulators of heavy metals, in which Cd was distributed more in the aerial part of plant. The results suggest that the mining ecotype S. alfredii is a new species of Cd hyperaccumulator.
文摘The switch from C-3 to CAM pathway was induced by water stress in a C-3/CAM intermediate plant Sedum spectabile Boreau. Typical CAM criteria were observed upon 15 d of withholding water. Leaf delta(13)C value (-%) and water content showed a linear correlation fashion. Chlorophyll fluorescence parameters and antioxidative capacity were altered by water stress. Phi(PSII) and q(P) were reduced by 50% and 34% of the control, respectively, while NPQ rose ca. 180%. SOD activity and ability to scavenge DPPH. free radical went down but membrane permeability changed slightly. However, when an additional photooxidation by MV with high PPFD was carried out with leaf discs from watered (C-3 mode) and drought plants (CAM mode), q(P) and Phi(PSII) in leaves at induced CAM mode stage continuously decreased to a very low level. High 1 - q(P) value (0.86) and 1 - q(P)/NPQ ratio (>1) indicated the presence of high reduction state and unbalance of light energy budget. Together with the marked loss of membrane integral, it was evidenced that photooxidative damage was more serious in the induced CAM mode than in the C-3 mode. No advantage of photooxidation tolerance was found at the induced CAM expression stage of the facultative CAM plant, as compared with its C-3 mode stage, and also with the constitutive CAM plants reported previously. The differences in photooxidation sensitivity between the inducible CAM expressing plant and the constitutive CAM plant were discussed.
基金supported by the National Natural Science Foundation of China (Nos.41977274, 41807123)the Shaanxi Province Key Research & Development Plan (No.2018ZDXMSF-022)the Scientific Research Program Funded by Shaanxi Provincial Education Department (No.18JK0100).
文摘Phytoremediation is a cost-effective and environment-friendly strategy for decontaminating heavy-metal-contaminated soil.However, the practical use of phytoremediation is constrained by the low biomass of plants and low bioavailability of heavy metals in soil.A pot experiment was conducted to investigate the effects of the metal chelator ethylenediaminetetraacetic acid(EDTA) and EDTA in combination with plant growth-promoting rhizobacteria(Burkholderia sp.D54 or Burkholderia sp.D416) on the growth and metal uptake of the hyperaccumulator Sedum alfredii Hance.According to the results, EDTA application decreased shoot and root biomass by 50% and 43%, respectively.The soil respiration and Cd,Pb, Zn uptake were depressed, while the photosynthetic rate, glutathione and phytochelatin(PC) contents were increased by EDTA application.Interestingly, Burkholderia sp.D54 and Burkholderia sp.D416 inoculation significantly relieved the inhibitory effects of EDTA on plant growth and soil respiration.Compared with the control, EDTA + D416 treatment increased the Cd concentration in shoots and decreased the Pb concentration in shoots and roots, but did not change the Zn concentration in S.alfredii plants.Furthermore,EDTA, EDTA + D54 and EDTA + D416 application increased the cysteine and PC contents in S.alfredii(p < 0.05);among all tested PCs, the most abundant species was PC2, and compared with the control, the PC2 content was increased by 371.0%, 1158.6% and 815.6%,respectively.These results will provide some insights into the practical use of EDTA and PGPR in the phytoremediation of heavy-metal-contaminated soil by S.alfredii.
基金supported by the National Natural Science Foundation of China (No. 30630046, 40701074)the National High Technology Research and Development Program of China (No. 2009AA06Z316)+1 种基金the Ministry of Environmental Protection Program of China(No. 2011467057)the Shanghai Tongji Gao Tingyao Environmental Science & Technology Development Foundation (7th Winner, 2010)
文摘Improving the efficacy of phytoextraction is critical for its successful application in metal contaminated soils. Mineral nutrition affects plant growth and metal absorption and subsequently the accumulation of heavy metal through hyper-accumulator plants. This study assessed the effects of di-hydrogen phosphates （KH2PO4, Ca（H2PO4）2, NaH2PO4 and NH4H2PO4） application at three levels （22, 88 and 352 mg P/kg soil） on Sedum alfredii growth and metal uptake by three consecutive harvests on aged and Zn/Cd combined contaminated paddy soil. The addition of phosphates （P） significantly increased the amount of Zn taken up by S. alfredii due to increased shoot Zn concentration and dry matter yield （DMY） （P 〈 0.05）. The highest phytoextraction of Zn and Cd was observed in KH2PO4 and NH4H2PO4 treatment at 352 mg P/kg soil. The amount of Zn removed by phytoextraction increased in the order of 1st clipping 〈 2nd clipping 〈 3rd clipping, and for Cd extraction the order was 2nd clipping 〈 1st clipping 〈 3rd clipping. These results indicate that the application of P fertilizers coupled with multiple cuttings can enhance the removal of Zn and Cd from contaminated soils by S. alfredii, thus shortening the time needed for accomplishing remediation goals.
基金Project supported by the National Natural Science Foundation of China(No.31000935)he Fundamental Research Funds for the Central Universities(No.2012FZA6008)the Department of Science & Technology of Zhejiang Province(No.2011C22077),China
文摘The elucidation of a natural strategy for metal hyperaccumulation enables the rational design of technologies for the clean-up of metal-contaminated soils.Organic acid has been suggested to be involved in toxic metallic element tolerance,translocation,and accumulation in plants.The impact of exogenous organic acids on cadmium(Cd) uptake and translocation in the zinc(Zn)/Cd co-hyperaccumulator Sedum alfredii was investigated in the present study.By the addition of organic acids,short-term(2 h) root uptake of 109 Cd increased significantly,and higher 109 Cd contents in roots and shoots were noted 24 h after uptake,when compared to controls.About 85% of the 109 Cd taken up was distributed to the shoots in plants with citric acid(CA) treatments,as compared with 75% within controls.No such effect was observed for tartaric acid(TA).Reduced growth under Cd stress was significantly alleviated by low CA.Long-term application of the two organic acids both resulted in elevated Cd in plants,but the effects varied with exposure time and levels.The results imply that CA may be involved in the processes of Cd uptake,translocation and tolerance in S.alfredii,whereas the impact of TA is mainly on the root uptake of Cd.
基金supported by the National Key Research and Development Project of China (No. 2016YFD0800801)the National Natural Science Foundation of China (No. 41771345)the Fundamental Research Funds for the Central Universities (2019FZJD007)
文摘Sedum alfredii Hance is a cadmium(Cd)/zinc(Zn)hyperaccumulator native to China.However,its relatively low biomass restricted the large-scale application for heavy metal contamination remediation.The chromosome set doubling of S.alfredii in vitro was achieved by 0.1%–0.2%(W/V)colchicine treatment.The plant DNA ploidy was analyzed by flow cytometry and chromosome set doubling plants(CSD)were identified based on the obvious different sharp peak.A tissue culture experiment with different Cd treated levels and a field trial with natural polluted mined soil were conducted to study the effects of chromosome doubling on plant biomass and Cd accumulation in shoots.The results suggested that S.alfredii is a mixoploid.Compared with the wild type plants(WT),CSD exhibited typical"gigas"characteristics in morphology including stem thickness,root hair production,number of leaves and size of stoma guard cell.Fresh weight and dry weight of CSD were increased to 1.62–2.03-fold and 2.26–3.25-fold of WT.And Cd content of CSD showed a17.49%–42.82%increase and 59%increase under tissue culture and field condition,accordingly.In addition,the TF and in BCF of CSD were 2.37-and 1.59-fold of WT,respectively.These results proved that it is feasible to promote phytoextraction efficiency of S.alfredii in Cd contaminated soils through chromosomal engineering,which provides a novel approach for hyperaccumulator application in phytoremediation.
基金supported by the National Natural Science Foundation of China (No. 20907040,20877068)the National High Technology Research and Development Program (863) of China (No. 2009AA06Z316)+2 种基金the Public Science and Technology Research Funds Projects of the Ministry of Environmental Protection of China (No.201109018)the Major State Basic Research Development Program of China (No. 2009CB119000)the Scientific Research Fund of Zhejiang Provincial Education Department of China (No. Y200908848)
文摘Combined pollution of 1,1,1-trichloro-2,2-bis （4-chlorophenyl） ethane （DDT） and cadmium （Cd） in agricultural soils is of great concern because they present serious risk to food security and human health.In order to develop a cost-effective and safe method for the removal of DDTs and Cd in soil,combined remediation of DDTs and Cd in soil by Sphingobacterium sp.D-6 and the hyperaccumulator,Sedum alfredii Hance was investigated.After treatment for 210 days,the degradation half-lives of DDTs in soils treated by strain D-6 decreased by 8.1% to 68.0% compared with those in the controls.The inoculation of strain D-6 into soil decreased the uptake of DDTs by pak choi and S.alfredii.The shoots/roots ratios of S.alfredii for the Cd accumulation ranged from 12.32 to 21.75.The Cd concentration in soil decreased to 65.8%-71.8% for S.alfredii treatment and 14.1%-58.2% for S.alfredii and strain D-6 combined treatment,respectively,compared with that in the control.The population size of the DDTs-degrading strain,Simpson index （1/D） and soil respiratory rate decreased in the early stage of treatment and then gradually increased,ultimately recovering to or exceeding the initial level.The results indicated that synchronous incorporation of strain D-6 and S.alfredii into soil was found to significantly （p 0.05） enhance the degradation of DDTs in soil and the hyperaccumulation of Cd in S.alfredii.It was concluded that strain D-6 and S.alfredii could be used successfully to control DDTs and Cd in contaminated soil.
基金Project supported by the Program for Changjiang Scholars and Innovative Research Team in University (No. IRT0536), the National Natural Science Foundation of China (No. 20277035), and the Post-doctoral Science Foundation of China (No. 2005038285)
文摘Radiotracer techniques were employed to characterize 65Zn adsorption and desorption in root-cell-wall of hyperac-cumulating ecotype (HE) and non-hyperaccumulating ecotype (NHE) species of Sedum alfredii Hance. The results indicated that at the end of a 30 min short time radioisotope loading period, comparable amounts of 65Zn were accumulated in the roots of the two ecotypes Sedum alfredii, whereas 2.1-fold more 65Zn remains in NHE root after 45-min desorption. At the end of 60 min uptake period, no difference of 65Zn accumulation was observed in undesorbed root-cell-wall of Sedum alfredii. However, 3.0-fold more 65Zn accumulated in desorbed root-cell-wall of NHE. Zn2+ binding in root-cell-wall preparations of NHE was greater than that in HE under high Zn2+ concentration. All these results suggested that root-cell-wall of the two ecotypes Sedum alfredii had the same ability to adsorb Zn2+, whereas the desorption characteristics were different, and with most of 65Zn binding on root of HE being available for loading into the xylem, as a result, more 65Zn was translocated to the shoot.
