Publications by authors named "Zhenming Xie"

12 Publications

  • Page 1 of 1

Astaxanthin and its gold nanoparticles mitigate cadmium toxicity in rice by inhibiting cadmium translocation and uptake.

Sci Total Environ 2021 Sep 3;786:147496. Epub 2021 May 3.

National Key Laboratory of Rice Biology, Institute of Crop Sciences, Zhejiang University, Hangzhou, China. Electronic address:

Cadmium (Cd) is one of the main heavy metal in rice, Cd uptake by cereal crops from soil leads to toxicity in plants and pose serious health risks due to human body's accumulation through the food chain. Astaxanthin, a natural and anti-oxidative oxycarotenoid, is widely distributed in various microorganisms and seafood. In this study, we demonstrated that astaxanthin in the form of gold nanoparticles (Ast-AuNPs) can efficiently alleviate Cd toxicity to a greater extent in hydroponically grown rice plants than single astaxanthin. When supplemented with 100 μg/mL Ast-AuNPs in medium, the Cd level of rice was significantly reduced by 26.2% (in roots) and 85.9% (in leaves), respectively. We also found Ast-AuNPs supplement restores chlorophyll biosynthesis and mitigate Cd-induced oxidative stresses: the contents of superoxide anion (O), hydrogen peroxide (HO), and malondialdehyde (MDA) were significantly reduced while the activity of the antioxidant enzymes (superoxide dismutase, peroxidase, and catalase) was significantly elevated. Further study showed that the supplement of Ast-AuNPs inhibited Cd-induced gene expression of the metal transporter genes (OsHMA2, OsHMA3, OsIRT1, OsIRT2, OsNramp1, and OsNramp5) in rice roots. Moreover, Ast-AuNPs regulated the metabolism of free amino acids and increased the level of non-enzymatic antioxidants such as glutathione and ascorbic acid. Therefore, this study demonstrates that Ast-AuNPs could mitigate the Cd toxicity in rice seedlings by suppressing Cd uptake, scavenging of ROS, and enhancing the activity of antioxidants, and also expands the application of functional gold nanoparticles in the alleviation of heavy metal pollution in plants.
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http://dx.doi.org/10.1016/j.scitotenv.2021.147496DOI Listing
September 2021

Colonized extremophile Deinococcus radiodurans alleviates toxicity of cadmium and lead by suppressing heavy metal accumulation and improving antioxidant system in rice.

Environ Pollut 2021 Apr 18;284:117127. Epub 2021 Apr 18.

MOE Key Laboratory of Biosystems Homeostasis & Protection, College of Life Sciences, Zhejiang University, Hangzhou, China; Key Laboratory for Green Processing of Chemical Engineering of Xinjiang Bingtuan, School of Chemistry and Chemical Engineering, Shihezi University, Shihezi, China. Electronic address:

Cadmium (Cd) and lead (Pb) are the major toxic heavy metals accumulated in rice and pose a serious threat to human health. The most important remediation strategy is to reduce the translocation of these heavy metals from polluted soil to rice. Bioremediation using microorganisms had been widely used for preventing environmental heavy metal pollution, and the interaction between microorganisms and plants is critical to reduce the heavy metal stress. In this study, we demonstrated that an extremophile Deinococcus radiodurans, especially its mutant strain-Δdr2577 which is deficient in cell surface-layer, could efficiently prevent the translocation and damages of Cd or Pb in rice. The bacterial cells efficiently removed Cd or Pb from culture medium. Following colonization of Δdr2577 cells in rice root, Cd level decreased to 71.6% in root and 60.9% in shoot, comparing to the plants treated with Cd alone; Pb level decreased to 73.3% in root and 56.9% in shoot, comparing to the plants treated with Pb alone. Meanwhile, the bacterial cells released their intracellular antioxidant-related molecules including glutamate and manganese ions into culture medium. Accumulation of glutamate and manganese ions detected in rice root and shoot ameliorate Cd/Pb-induced oxidative stress as indicated by reduced levels of ROS and enhanced activities of antioxidant enzymes in rice. Our results provide a potential application of an extremophile bacterium in alleviating heavy metal toxicity in rice. The main findings of the work reveal the interaction between the D. radiodurans and rice, as well as the alleviating mechanism of Cd and Pb toxicity through suppressing heavy metal accumulation and improving the antioxidant system in rice by the extremophile bacterium.
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http://dx.doi.org/10.1016/j.envpol.2021.117127DOI Listing
April 2021

Dynamic Polyphosphate Metabolism Coordinating with Manganese Ions Defends against Oxidative Stress in the Extreme Bacterium Deinococcus radiodurans.

Appl Environ Microbiol 2021 03 11;87(7). Epub 2021 Mar 11.

MOE Key Laboratory of Biosystems Homeostasis & Protection, College of Life Sciences, Zhejiang University, Hangzhou, China

is an extreme bacterium with unparalleled resistance to oxidative stresses. Accumulation of intracellular Mn complexing with small metabolites is the key contributor to the tolerance of against oxidative stress. However, the intracellular reservoir of Mn ions and homeostatic regulation of the Mn complex in remain unclear. We identified an evolutionarily ancient and negatively charged phosphate polymer (polyphosphate [PolyP]) in We investigated PolyP metabolism in the response of to oxidative stress. The genes , encoding polyphosphatase kinase (PPK; the subscript "" refers to ), and , encoding exopolyphosphatase (PPX), were identified. PPX is a novel exopolyphosphatase with a cofactor preference to Mn, which enhances the dimerization and activity of PPX to allow the effective cleavage of PolyP-Mn. PPK and PPX exhibited different dynamic expression profiles under oxidative stress. First, was upregulated leading to the accumulation of PolyP, which chelated large amounts of intracellular Mn ions. Subsequently, the expression level of decreased while was substantially upregulated and effectively hydrolyzed inactive PolyP-Mn to release phosphate (Pi) and Mn, which could form into Mn-Pi complexes to scavenge O and protect proteins from oxidative damage. Hence, dynamic cellular PolyP metabolites complexed with free Mn ions highlight a defense strategy of in response to oxidative stress. The Mn-phosphate complex (Mn-Pi) plays a key role in the cellular resistance of radioresistant bacteria. The evolutionarily ancient polyphosphate polymers (polyphosphate [PolyP]) could effectively chelate Mn and donate phosphates. However, the intracellular reservoir of Mn ions and homeostatic regulation of the Mn-Pi complex remain unclear. Here, we investigated the relationship of PolyP metabolites and Mn homeostasis and how they function to defend against oxidative stress in the radioresistant bacterium We found that PPX (the subscript "" refers to ) is a novel exopolyphosphatase with a cofactor preference for Mn, mediating PolyP-Mn degradation into Pi and Mn ions. The formed Mn-Pi complexes effectively protect proteins. The dynamic PolyP metabolism coordinating with Mn ions is a defense strategy of in response to oxidative stress. The findings not only provide new insights into the resistance mechanism of the extreme bacterium but also broaden our understanding of the functions of PolyP metabolism in organisms.
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http://dx.doi.org/10.1128/AEM.02785-20DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8091604PMC
March 2021

Advances in the Biosynthetic Pathways and Application Potential of Plasmalogens in Medicine.

Front Cell Dev Biol 2020 31;8:765. Epub 2020 Aug 31.

MOE Key Laboratory of Biosystem Homeostasis and Protection, College of Life Sciences, Zhejiang University, Hangzhou, China.

Plasmalogens are a special class of polar glycerolipids containing a vinyl-ether bond and an ester bond at sn-1 and sn-2 positions of the glycerol backbone, respectively. In animals, impaired biosynthesis and regulation of plasmalogens may lead to certain neurological and metabolic diseases. Plasmalogens deficiency was proposed to be strongly associated with neurodegenerative and metabolic diseases, such as Alzheimer's disease (AD) and Parkinson's disease (PD), and appropriate supplement of plasmalogens could help to prevent and possibly provide therapy of these diseases. Plasmalogens evolved first in anaerobic bacteria with an anaerobic biosynthetic pathway. Later, an oxygen-dependent biosynthesis of plasmalogens appeared in animal cells. This review summarizes and updates current knowledge of anaerobic and aerobic pathways of plasmalogens biosynthesis, including the enzymes involved, steps and aspects of the regulation of these processes. Strategies for increasing the expression of plasmalogen synthetic genes using synthetic biology techniques under specific conditions are discussed. Deep understanding of plasmalogens biosynthesis will provide the bases for the use of plasmalogens and their precursors as potential therapeutic regimens for age-related degenerative and metabolic diseases.
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http://dx.doi.org/10.3389/fcell.2020.00765DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7487321PMC
August 2020

Engineering and optimization of phosphate-responsive phytase expression in Pichia pastoris yeast for phytate hydrolysis.

Enzyme Microb Technol 2020 Jun 7;137:109533. Epub 2020 Feb 7.

Technological and Higher Education Institute of Hong Kong, Hong Kong, China. Electronic address:

Phytate is the major storage form of phosphorus in plants. It is present in cereals and raw materials of vegetable origin used in animal and human diets. However, non-ruminant animals have little phytase activity in their guts and, therefore, cannot digest phytate. As a result, almost all dietary phytate is discharged into the environment, causing phosphorus pollution. Phytate is also considered as an "antinutrient" for its ability to form insoluble and stable complexes with metal ions, thus reducing dietary absorption of essential minerals. It is a dire need to develop sustainable approaches for environmentally-friendly utilization for this valuable and abundant natural resource. To this end, we engineered Pichia pastoris to express and secrete phytase in a "made-to-order" fashion in response to external level of inorganic phosphate (Pi). Responsiveness to external Pi level was achieved by generating a Pi-responsive promoter library using directed evolution. The resultant yeast strains were proven to liberate Pi from wheat-based meal in a simulated in vitro digestion model. These yeast-based whole cell biocatalysts may serve as platform hosts with potential applications in food processing industry and animal waste treatment.
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http://dx.doi.org/10.1016/j.enzmictec.2020.109533DOI Listing
June 2020

Application of a fluorescent derivatization reagent 9-chloromethyl anthracene on determination of carboxylic acids by HPLC.

J Chromatogr Sci 2012 Jul 11;50(6):464-8. Epub 2012 Apr 11.

Faculty of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006, PR China.

A simple and sensitive high-performance liquid chromatography (HPLC) method is proposed for the analysis of some carboxylic acids in food samples and the environment. The use of 9-chloromethyl anthracene as a fluorescence-labeling reagent has been investigated. The derivatization reagent reacts with unitary carboxylic acids and tetrabutylammonium bromide as a catalyst within 50 min in acetonitrile to give esters, which can be separated by HPLC employing fluorescence detection at λ(ex) = 365 and λ(em) = 410 nm. The optimum conditions for derivatization, fluorescence detection and chromatographic separation are established. The method shows good sensitivity, with a detection limit from 0.18 to 2.53 pmol, and good linearity between 1-250 nmol/mL of each analyte. The practical applicability of the method was demonstrated by analyzing samples that were spiked with the acid standards, environment and food samples.
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http://dx.doi.org/10.1093/chromsci/bms023DOI Listing
July 2012

Effects of rural-urban return migration on women's family planning and reproductive health attitudes and behavior in rural China.

Stud Fam Plann 2010 Mar;41(1):31-44

East-West Center, Population and Health Studies, Research Program, Honolulu, HI, USA.

This study examines the effects of rural-urban return migration on women's family planning and reproductive health attitudes and behavior in the sending areas of rural China. Based on data from a survey of rural women aged 16-40 in Sichuan and Anhui Provinces in 2000, our study finds that migrant women returning from cities to the countryside, especially those who have been living in a large city, are more likely than nonmigrant women to adopt positive family planning and reproductive health attitudes and behavior in their rural communities of origin. We find, moreover, that living in a rural community where the prevalence of such return migrant women is higher is positively associated with new fertility and gender attitudes and with knowledge of self-controllable contraceptives. The findings of significant rural-urban return-migration effects have important policy implications for shaping family planning and reproductive health attitudes and behaviors in rural China.
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http://dx.doi.org/10.1111/j.1728-4465.2010.00222.xDOI Listing
March 2010

Determination of sodium monofluoroacetate (1080) in biological samples as its 4-bromomethyl-7-methoxycoumarin derivative by RP-HPLC.

J Chromatogr Sci 2007 Aug;45(7):405-8

School of Chemistry and Chemical Engineering, Sun Yet-Sen University, Guangzhou 510275, PR China.

A high-performance liquid chromatography (HPLC) method with fluorescence detection is described for the determination of sodium monofluoroacetate (MFA-Na) in biological samples. 4-Bromomethyl-7-methoxycoumarin is used as a derivatization reagent and reacted with MFA-Na to form 7-methoxy-4-methylenecoumarin monofluoroacetate for HPLC analysis. Chromatographic separation is performed on a Hewlett Packard RP-18 column using methanol-water (60:40, v/v) as the mobile phase. A fluorescent detector is employed with the excitation and emission wavelengths as 319 nm and 390 nm, respectively. The novel method yields a good linear relationship when the concentration of MFA-Na is within 1 and 500 nmol/mL (r = 0.9996). The detection limit is 50 pmol/mL. The established method is applied to determine MFA-Na in biological samples. The recovery rates of MFA-Na are between 81% and 88%, and the relative standard deviations are less than 5%. The method shows good sensitivity and selectivity for the determination of MFA-Na in biological samples.
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http://dx.doi.org/10.1093/chromsci/45.7.405DOI Listing
August 2007

Quantitative analysis of monofluoroacetate in biological samples by high-performance liquid chromatography using fluorescence labeling with 9-chloromethylanthracene.

J Chromatogr B Analyt Technol Biomed Life Sci 2007 Sep 1;857(1):53-8. Epub 2007 Jul 1.

School of Chemistry and Chemical Engineering, Sun Yet-Sen University, Guangzhou, PR China.

A rapid and sensitive RP-HPLC method with fluorescence detection has been developed for the quantitative analysis of trace amounts of monofluoroacetate (MFA) in biological samples as serum, food and meat. 9-Chloromethylanthracene (9-CMA) is used as the fluorescence labeling reagent. Samples were extracted and reacted with 9-chloromethylanthracene together with tetrabutylammonium bromide as catalyst at 80 degrees C for 50 min to give a new fluorescent derivative as 9-methyleneanthracene monofluoroacetate (MA-MFA). The resulting MA-MFA was characterized with IR, (1)H NMR, (13)C NMR and MS. Chromatography separation is performed on an Agilent Hypersil ODS column with a fluorescent detector employed with the excitation and emission wavelengths as 256 nm and 412 nm, respectively. Optimal conditions for derivatization, fluorescence detection and chromatographic separation have been established. The novel method yields a good linear relationship when the MFA concentration in serum within 1 and 250 ng/mL (r=0.9988). The detection limit (signal-to-noise ratio=3 with 2 microL injected) was 0.25 ng/mL. The practical applicability of this method was demonstrated by quantitative determination of MFA-Na in a blood sample from a person who had ingested the poison.
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http://dx.doi.org/10.1016/j.jchromb.2007.06.028DOI Listing
September 2007

Son preference, use of maternal health care, and infant mortality in rural China, 1989-2000.

Popul Stud (Camb) 2007 Jul;61(2):161-83

East-West Center, Honolulu, HI 96848, USA.

This study assesses the effects of socio-economic conditions and the interaction between son preference and China's one-child family planning policy on the use of maternal health care services and their effects on infant mortality in rural China, using nationally representative data from the 2001 National Family Planning and Reproductive Health Survey. The results show that while the use of maternal health care services has continued to increase over time, large gaps still exist in the use of these services and in infant survival by mother's education, community income, and parity. Further improvements in the reproductive health of all women and in infant survival will require effective reduction of the obstacles to the use of maternal health care among those women in rural China who are less educated, poor, and of higher parity.
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http://dx.doi.org/10.1080/00324720701340194DOI Listing
July 2007

Quality of care in China: scaling up a pilot project into a national reform program.

Stud Fam Plann 2006 Mar;37(1):17-28

AIDS Public Policy Project, John F. Kennedy School of Government, Harvard University, USA.

China's family planning program ranks as history's most intensive effort to control national population growth. Although advocates for global population control have lauded China's effort to limit births as afundamental part of its sustainable development goals, the country's population policy has also generated much international criticism. As China enters the new millennium, a long-overdue reform of its approach to implementing its family planning program has begun to refocus the program on clients' needs, informed choice of contraceptives, and better-quality services. Originally inspired by the 1994 International Conference on Population and Development held in Cairo, the reform program began as a pilot project among six counties and has now become a blueprint for reorienting the national family planning program. This article reviews the process by which a small, innovative pilot project was scaled up into a national reform effort and the key lessons learned about scaling up sensitive but necessary innovation in a difficult political environment.
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http://dx.doi.org/10.1111/j.1728-4465.2006.00080.xDOI Listing
March 2006

Family planning and women's lives in rural China.

Int Fam Plan Perspect 2004 Jun;30(2):68-76

POLICY Project, The Futures Group.

Context: By 1979, China had begun implementing the so-called one-child policy, which severely restricts couples' childbearing. It is important to understand Chinese women's perceptions of how their lives have been affected by this policy and by the use of family planning.

Methods: Survey and focus group data collected in 1996 and 1998 from women in three Chinese provinces-Jiangsu, Anhui and Yunnan-were used to examine links connecting family planning and childbearing to women's lives within the family, including their relationships with spouses and other family members, and their opportunities for education, employment and social activities.

Results: Women related family planning to the country's economic situation and to their ability to prosper by having fewer children to support. Increased prosperity enabled them to provide for children's education and to build them houses. In Jiangsu, 73-75% of respondents who had had one child were satisfied with their number of children, regardless of sex; in Anhui and Yunnan, 54-58% of women who had one son and no daughter reported being satisfied, compared with 31-50% of women who had one daughter and no sons. The great majority (73-99%) of women in all three provinces who had two children-regardless of sex-were satisfied with their number of children.

Conclusions: Few women disputed that women's lives were better now than in the past. China's one-child policy, however, places women-particularly those in rural areas-in a situation where they are pressured by the government's childbearing requirements on one side and by society's preference for sons on the other.
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http://dx.doi.org/10.1363/3006804DOI Listing
June 2004