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Journal of Integrative Plant Biology 2006年第8期48卷 928-937页

作者： Jiangchuan Li Jiangbo Guo Wenzhong Xu Mi Ma Key Laboratory of Photosynthesis and Environmental Molecular Physiology Institute of Botany the Chinese Academy of Sciences Beijing 100093 China Graduate School of the Chinese Academy of Sciences Beijing 100039 China

Bermudagrass （Cynodon dactylon L. cv. Goldensun） is highly resistant to and accumulates large amounts of cadmium （Cd）. A phytochelatin synthase （PCS） cDNA （CdPCS1） was isolated from this grass by rapid amplification of cDNA ends. The putative CdPCS1 protein shared a high homology with PCS from other plants, with 79% homology at the N-terminal and 47% homology at the C-terminah However, 16 Cys residues were found at the C-terminal of CdPCS1, and among these residues, three positions were different from other PCS proteins. Semiquantitative reverse transcription-polymerase chain reaction analysis showed that Cd stress induced CdPCS1 expression in both roots and leaves in Bermudagrass. We verified that CdPCS1 plays an important role in Cd tolerance in yeast cells by expressing the gene in ABDE1, a Cdsensitive mutant. CdPCS1 was then introduced into tobacco plants. The phytochelatin level in some transgenic tobacco lines increased 3.88-fold more than in wild type plants and Cd accumulation in these transgenic plants was enhanced 3.21-fold accordingly. The results suggested that CdPCS1 could be used as a gene element for phytoremediation in the future.

关键词： cadmium Cynodon dactylon phytochelatin phytochelatin synthase phytoremediation.

Arsenic speciation for the phytoremediation by the Chinese brake fern,Pteris vittata

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Journal of Environmental Sciences 2008年第12期20卷 1463-1468页

作者： R.Shoji R.Yajima Y.Yano Department of Chemical Science and Engineering Tokyo National College of Technology1220-2 KunugidaHachioji

Arsenic(As)speciation for the phytoremediation by the Chinese brake fern was studied.In particular,the mechanism of how plants induce compounds containing thiol(SH)and proteins by As exposure in terms of the relationship between As and phosphate uptaken into plant cells was examined.Pteris vittata callus could effciently reduce As(V)to As(III)by the rapid introduction of reductase and synthesize thiols leading to phytochelatins production.Furthermore,Pteris vittata could control phosphate concentration in t...

关键词： arsenic hyper accumulator phosphorus thiol phytochelatin

Effects of EDTA and plant growth-promoting rhizobacteria on plant growth and heavy metal uptake of hyperaccumulator Sedum alfredii Hance

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Journal of Environmental Sciences 2020年第2期32卷 361-369页

作者： JunKang Guo Xin Lv HongLei Jia Li Hua XinHao Ren Haris Muhammad Ting Wei Yongzhen Ding School of Environmental Science and Engineering Shaanxi University of Science&TechnologyXi'an 710021China Agro-Environmental Protection Institute Ministry of AgricultureTianjin 300191China

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.

关键词： Phytoremediation EDTA Plant-growth-promoting bacteria Sedum alfredii Hance phytochelatin

Physiological and biochemical analysis of mechanisms underlying cadmium tolerance and accumulation in turnip

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Plant Diversity 2018年第1期40卷 19-27页

作者： Xiong Li Xiaoming Zhang YuanshengWu Boqun Li Yongping Yang Key Laboratory for Plant Diversity and Biogeography of East Asia Kunming Institute of BotanyChinese Academy of SciencesKunmingChina China Germplasm Bank of Wild Species Kunming Institute of BotanyChinese Academy of SciencesKunmingChina University of Chinese Academy of Sciences BeijingChina College of Plant Protection Yunnan Agricultural UniversityKunmingChina

The capacity of plants to accumulate cadmium(Cd) is significant for phytoremediation of Cd-polluted soils. Turnips cultivated in China include species featuring high Cd accumulation and some of these plants act as Cd hyperaccumulator landraces. These plants can accumulate over 100 mg Cd kg^(-1) dry weight in leaves without injury. Hence, studies that explore mechanisms underlying Cd detoxification and transport in turnip plants are essential. In the present study, we compared physiological and biochemical changes in turnip leaves treated with two Cd concentrations to controls. We discovered that Cd stress significantly increased the enzymatic activities or compound contents in the antioxidant system, including members of the glutathione-ascorbic acid cycle, whereas oxidation of reactive oxygen species(ROS) remained stable. Cd treatments also increased the contents of phytochelatins as well as a number of amino acids. Based on these results, we conclude that turnips initiate a series of response processes to manage Cd treatment. First, the antioxidant system maintaining ROS homeostasis and osmotic adjustment is excited to maintain stability of cell osmotic potential. Cd is chelated into its stable form to reduce its toxicity. Cd is possibly transported to vacuoles or non-protoplasts for isolation. Amino acid synthesis may directly and indirectly play an important role in these processes. This study partly revealed physiological and biochemical mechanisms underlying turnip response to Cd stress and provides information on artificially increasing or decreasing Cd accumulation in turnips and other plants.

关键词： Turnip Cadmium Detoxification Antioxidant system phytochelatin

Arsenic Stress Responses and Tolerance in Rice: Physiological, Cellular and Molecular Approaches

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Rice science 2018年第5期25卷 235-249页

作者： Jyotirmay KALITA Amit Kumar PRADHAN Zina Moni SHANDILYA Bhaben TANTI Department of Botany Gauhati University

Arsenic （As）, a potentially toxic metalloid released in the soil environment as a result of natural as well as anthropogenic processes, is subsequently taken up by crop plants. In rice grains, As has been reported in Asia, North America and Europe, suggesting a future threat to food security and crop production. As3＋ by dint of its availability, mobility and phytotoxicity, is the most harmful species of As for the rice crop. Specific transporters mediate the transport of different species of As from roots to the aboveground parts of the plant body. Accumulation of As leads to toxic reactions in plants, affecting its growth and productivity. Increase in As uptake leads to oxidative stress and production of antioxidants to counteract this stress. Cultivars tolerant to As stress are efficient in antioxidant metabolism compared to sensitive ones. Iron and selenium are found to have ameliorating effect on the oxidative stress caused by As. Microbes, even many indigenous ones, in the plant rhizosphere are also capable of utilizing As in their metabolism, both independently and in association. Some of these microbes impart tolerance to As-stress in plants grown in As contaminated sites.

关键词： arsenic rice phytotoxicity hyperaccumulator phytochelatin antioxidant mitigation

Comparison of physiological responses to oxidative and heavy metal stress in seedlings of rice paddy, Oryza sativa L.

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Journal of Environmental Sciences 2000年第4期12卷 458-462页

作者： YU Guo\|ying, WANG Guo\|ping, HE Chi\|quan (Lab for Wetland Process and Environment, Changchun Institute of Geography, The Chinese Academy of Sciences, Changchun 130021,China E\|mail: yuguoying@***) 中科院长春地理所湿地环境开放实验室吉林长春 1 3 0 0 2

Physiological responses on the bases of activities of antioxidant enzymes: peroxidase, catalase, superoxide dismutase and glutathione reductase as well as estimation of total protein, lipid peroxidation and thiols in the form of protein, non\|protein, glutathione and phytochelatin measured in growing seedlings of paddy, Oryza sativa L., from day 2 to 8 were compared following treatment of seeds for 5h with oxidative agents, paraquat 5 × 10 -5 , 10 -4 , 10 -3 mol/L, H 2O 2 10 -3 , 5×10 -3 , 10 -2 mol/L, and CdCl 2 10 -5 , 10 -4 , 5×10 -3 mol/L. A significant induction of all antioxidant enzymes along with an increase in the levels of protein, lipid peroxidation and glutathione was noted in response to oxidative stress, CdCl 2 induced significant peroxidase and catalase activities but not superoxide dismutase. In a marked contrast from oxidative stress, CdCl 2 decreased glutathione reductase activity as well as glutathione levels but increased phytochelatin level. The different physiological responses thus underlined the crucial involvement of glutathione and phytochelatin in the oxidative and heavy metal\|linduced adaptive responses respectively.

关键词： adaptive response oxidative stress heavy metal antioxidant enzymes glutathione phytochelatin

The Purification and Rapid Identification of Heavy Metal-binding Peptides of Water Hyacinth

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Science China Chemistry 1994年第3期37卷 303-309页

作者：丁翔王文清姜剑茹炳根王英彦 Department of Technical Physics Peking University Beijing 100871 PRC Department of Biology Peking University Beijing 100871 PRC Institute of Environmental Protection Beijing 100081 PRC

This paper studies the rapid identification of heavy metal-binding peptides (phytochelatin) by taking Water Hyacinth as a model plant. Plants were cultured in water containing 2 μg/ml Cd2+ for 13 days. The Sephadex G-50 chromatography of root extract under low salt concentration (0. 01 mol/L PBS) gave a Cd-binding peak with MW of 10 ,000 determined by SEC HPLC. After oxidation with performic acid, its SEC HPLC molecular weight decreased to below 1300 and the reverse phase HPLC showed one peptide peak, whose amino acid composition is the same as that of the sample never undertaking oxidation, and (Glu/Gln):Cys:Gly=2:2:1. According to the general structure of phytochelatin (γ-Glu-Cys)n-Gly, n is 2 in this case. The protocol including the sequential steps of Sephadex G-50 chromatography→performic acid oxidation→reverse phase HPLC→amino acid analysis is a rapid and effective method to identify the existence of phytochelatin and determine its values of n.

关键词： phytochelatin water hyacinth identification metallothionein-like.