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1. Antioxidant Potential of Polyphenols and Tannins from Burs of Castanea mollissima Blume | |||
Shan Zhao,Jie Yuan Liu,Si Yu Chen,Ling Ling Shi,Yu Jun Liu,Chao Ma | |||
Biology 12 March 2012 | |||
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Abstract:Spiny burs of Castanea mollissima Blume (Chinese chestnut) are usually discarded as industrial waste during post-harvesting processing. The objective of this study was to establish an extraction and isolation procedure for tannins from chestnut burs, and to assess their potential antioxidant activity. Aqueous ethanol solution was used as extraction solvent, and HPD 100 macroporous resin column was applied for isolation. The influence of solvent concentration in the extraction and elution process on extraction yield, tannins and polyphenols content, as well as antioxidant potential, including DPPH and ABTS radical scavenging ability, reducing power ability and cellular antioxidant ability were assessed. In both the extraction and isolation process, 50% aqueous ethanol led to superior total tannins and polyphenols content as well as significantly higher antioxidant activity. In addition, the antioxidant activity and the total tannins content in extracts and fractions had a positive linear correlation, and the predominant components responsible for antioxidant activities were characterized as hydrolysable tannins. To the best of our knowledge, this is the first report on the enrichment of tannins from burs of C. mollissim using macroporous resin chromatography, and to assess the cellular antioxidant activity of them. | |||
TO cite this article:Shan Zhao,Jie Yuan Liu,Si Yu Chen, et al. Antioxidant Potential of Polyphenols and Tannins from Burs of Castanea mollissima Blume[OL].[12 March 2012] http://en.paper.edu.cn/en_releasepaper/content/4471313 |
2. Preliminary characterization of a novel Arabidopsis mutant with pliant shoots | |||
GAO Xiang | |||
Biology 23 February 2012 | |||
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Abstract:In this paper, a novel Arabidopsis mutant of Columbia ecotype was preliminarily characterized by phenotypic observation and genetic analysis. Most distinct phenotypes in this mutant were the tender and pliant shoots in the early growth phase and somewhat dense siliques below the shoot apex at maturity phase. In addition, the growth of the main and side shoots was stunted and rosette and axillary leaves were easy to age. Genetic analysis showed that the mutant phenotype was not co-segregated with the T-DNA insertion or kanamycin resistance, and the mutation was dominant. The gene responsible for such mutant phenotype remains to be cloned in the future work. | |||
TO cite this article:GAO Xiang. Preliminary characterization of a novel Arabidopsis mutant with pliant shoots[OL].[23 February 2012] http://en.paper.edu.cn/en_releasepaper/content/4462460 |
3. In vivo localization of action sites of tenuazonic acid in photosynthetic apparatus by chlorophyll a fluorescence kinetics OJIP | |||
CHEN Shiguo,ZHANG Min,Strasser Reto J?rg,QIANG Sheng | |||
Biology 02 February 2012 | |||
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Abstract:Tenuazonic acid (TeA), a phytotoxin produced by the fungus Alternaria alternata isolated from diseased Crofton weed (Eupatorium adenophorum), exhibits a strong inhibition in photosynthesis, especially photosystem II (PSII) activity. In vivo the chlorophyll fluorescence induction transient of host plant and in vitro fluorescence transient of six kinds of other higher plants show that TeA acts several sites in photosynthesis apparatus. First, as the classical PSII inhibitors, the most important action site of TeA is that it interrupts electron transport beyond QA on the acceptor side of PSII due to binding to the QB-niche. Moreover, TeA leads to severe inactivation of PSII reaction centers (RCs). On the other hand, TeA has no affect on the antenna pigments, the energy transfer from antenna pigment molecules to RCs, and the oxygen-evolving complex (OEC) at the donor side of PSII. Nevertheless, it's different from the known classical PSII inhibitors that the dominant influence of TeA is not on the primary photochemical reaction but the biochemical reaction after QA. On the basis of the competition experiments with [14C]atrazine, it's further confirmed that TeA does not share with atrazine and DCMU the same binding environment despite their common action target: the QB-site. Additionally, TeA causes inactivation of the FNR system and therefore the reduction of NADP+ at PSI electron acceptor side. These actions distinguish TeA from the classical photosynthesis inhibitors. This provides perhaps a new idea and approach to help the search and development of bioherbicides in tetramic acid families or biomimetic synthesis of new herbicides from TeA precursor. | |||
TO cite this article:CHEN Shiguo,ZHANG Min,Strasser Reto J?rg, et al. In vivo localization of action sites of tenuazonic acid in photosynthetic apparatus by chlorophyll a fluorescence kinetics OJIP[OL].[ 2 February 2012] http://en.paper.edu.cn/en_releasepaper/content/4464180 |
4. Expression of anthocyanin biosynthetic genes during fruit development in Fengxiang strawberry | |||
ZHOU Bo,LI Yuhua | |||
Biology 01 February 2012 | |||
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Abstract:Anthocyanins are the main pigments in flowers and fruits. In most cases, anthocyanin accumulation in fruit is highly controlled by the developmental level. In this study, the cDNA fragments of three genes, chalcone synthase (CHS), dihydroflavonol 4-reductase (DFR), and anthocyanidin synthase (ANS), which are involved in the flavonoid pathway, were isolated from total RNA of strawberry ripe fruit by using polymerase chain reaction technique and labeled as probes to determine the expression of anthocyanin biosynthetic genes. Northern analysis showed that a correlation between anthocyanin accumulation and expression of the flavonoid pathway genes during the ripening of strawberry fruits. At the early stages of fruit development, the mRNA levels encoding CHS, DFR, ANS were high probably responsible for the accumulation of condensed tannins, but the levels decreased dramatically when fruits turned white from green. During the stage of pigment accumulation, their mRNA levels increased strongly to be involved anthocyanin biosynthesis. Difference of CHS in mRNA abundance was correlated with differential accumulation of anthocyanins throughout the process of fruit development. Therefore, CHS could be a key structure gene involved in anthocyanin synthesis. Furthermore, the co-ordination of expression of anthocyanin biosynthetic genes implied a common regulatory mechanism controlling the expression of structural genes in the flavonoid pathway. | |||
TO cite this article:ZHOU Bo,LI Yuhua. Expression of anthocyanin biosynthetic genes during fruit development in Fengxiang strawberry[OL].[ 1 February 2012] http://en.paper.edu.cn/en_releasepaper/content/4464645 |
5. Optimization of Agrobacterium-mediated transformation system for soybean callus | |||
Liu Dong,Chang Dasong,Liu Sheng,Wang Dan,Wang Ningning | |||
Biology 29 December 2011 | |||
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Abstract:This report described a simple and efficient method of Agrobacterium-mediated transformation for obtaining transgenic callus tissues of soybean [Glycine max (L.) Merr.]. Hypocotyl segment explants of soybean were used as the starting material. To improve transformation efficiencies, several factors such as inoculation time, co-cultivation period and addition of antioxidants in co-cultivation medium (CCM) were examined. Callus tissues were induced at both the acropetal and basipetal ends of explants after about 2 weeks of culture on callus induction medium (CIM) containing 0.5 mgoL-1 6-Benzylaminopurine (6-BA) and 2.0 mgoL-1 2,4-Dichlorophenoxyacetic acid (2,4-D). The average transformation efficiency reached up to 87.7% based on GUS detection. | |||
TO cite this article:Liu Dong,Chang Dasong,Liu Sheng, et al. Optimization of Agrobacterium-mediated transformation system for soybean callus[OL].[29 December 2011] http://en.paper.edu.cn/en_releasepaper/content/4458595 |
6. Altered expression of plant miRNAs and their target mRNAs in tomato flower and fruit upon virus infections | |||
Lin Ruohong ,Junli Feng,Yuwei Wang,Jianning Liu,Jishuang Chen | |||
Biology 28 December 2011 | |||
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Abstract:The economic importance of tomato is well documented, and tomato has become a model for fleshy fruit development and ripening studies. Plant microRNAs (miRNAs) are small endogenous RNAs that are involved in a variety of activities, including plant development, signal transduction and protein degradation, as well as response to environment stress, and pathogen invasion. Here in this study, we aimed at quantifying the expression alterations of nine miRNAs and target mRNAs in tomato flower and fruit development upon CMV and TAV infections. Three different Cucumber mosaic virus (CMV) strains CMV-Fny, CMV-Fny2b, CMV-Fny-satT1 and Tomato aspermy virus (TAV)-Bj were used in our investigation, and the miRNA/mRNA expression alterations were analyzed by real-time quantitative RT-PCR. The results shown the levels of several miRNA/mRNA pairs were increased upon virus infection. However, the increased levels of individual miRNAs differed for different virus strains, reflecting differences in severity of symptom phenotypes. The altered expression pattern of these miRNA/mRNA pairs and their predicted functions indicate the possible roles in flower and fruit development, and provide experimental data for understanding the miRNA-mediated phenotype alterations in tomato fruit. | |||
TO cite this article:Lin Ruohong ,Junli Feng,Yuwei Wang, et al. Altered expression of plant miRNAs and their target mRNAs in tomato flower and fruit upon virus infections[OL].[28 December 2011] http://en.paper.edu.cn/en_releasepaper/content/4457683 |
7. Involvement of chloroplast-derived ROS in 3-acetyl-5-isopropyltetramic acid induced leaf necrosis in Arabidopsis thaliana | |||
CHEN Shiguo,Yin Chunyan,Zhou Fengyan,Strasser Reto J?rg,QIANG Sheng | |||
Biology 09 April 2011 | |||
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Abstract:3-AIPTA (3-acetyl-5-isopropyltetramic acid), a derivate of tetramic acid, can cause a brown leaf spot disease in many plants and may quickly kill seedlings of mono- and dicotyledonous plants. In this study, to further elucidate the mode of action of 3-AIPTA, a series of experiments was performed to assess the production and role of reactive oxygen species (ROS) during 3-AIPTA-induced cell necrosis. When Arabidopsis leaves were incubated with 3-AIPTA, the PSII electron transport beyond QA and the reduction of end acceptors at the PSI acceptor side were inhibited, followed by the occurrence of charge recombination and electron leakage to O2, resulting in the chloroplast-derived oxidative burst. However, the main antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX) lost their activity. Excess ROS molecules directly attacked a variety of cellular components and subsequently caused electrolyte leakage, lipid peroxidation and cell membrane disruption. Finally, this led to cell destruction and leaf tissue necrosis. Thus, 3-AIPTA-triggered leaf necrosis of Arabidopsis is a result of direct oxidative injury from the chloroplast-originated ROS burst attributed to the inhibition of photosynthetic electron transport. | |||
TO cite this article:CHEN Shiguo,Yin Chunyan,Zhou Fengyan, et al. Involvement of chloroplast-derived ROS in 3-acetyl-5-isopropyltetramic acid induced leaf necrosis in Arabidopsis thaliana[OL].[ 9 April 2011] http://en.paper.edu.cn/en_releasepaper/content/4421106 |
8. An Amperometric Enzyme Sensor Based on Poly-thionine An Impedance Immunosensor for the Detection of 2,4 - Dichlorophenoxyacetic Acid | |||
ZHONG Feifei,HUANG Zhigang,WANG Ruozhong,LI Hesong,XIAO Langtao | |||
Biology 04 March 2011 | |||
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Abstract:2, 4-Dichlorophenoxyacetic Acid (2,4-D), a widely used chemical in agriculture, is one of the main varieties of herbicides, but its biosafety risks become a new focus issue of human security. Traditional determination methods can not meet demand of food quality supervision and inspection because of their limitations. In this paper, a reagentless electrochemical impedance immunosensor for dichlorophenoxyacetic acid detection was developed based on the directly adsorbed anti- 2,4-D antibody on a porous nano-gold film when it was immobilized onto the porous nano-gold through electrostatic adsorption and covalently conjugation. The electrochemical impedance spectroscopy (EIS) was used to characterized the successful construction of the porous nano-gold film and the stepwise modifacation of the glassy-carbon electrode. As the interfacial electron transfer decreased, the impedance sigsenal would increase. The above results showed that the constructed electrode had good linearity with the 2,4-D content ranging of 0.5 ng/mL-5000 ng/mL and the linear equation is y = 0.045x + 62.55, and the correlation coefficient R is 0.9970, with a detection limit at about 0.1 ng/mL. It can directly obtained information through the impedance changes with the 2,4-D concentration. The results were consistently comparing with the results of HPLC which provides a new ways for detection of 2,4-D. | |||
TO cite this article:ZHONG Feifei,HUANG Zhigang,WANG Ruozhong, et al. An Amperometric Enzyme Sensor Based on Poly-thionine An Impedance Immunosensor for the Detection of 2,4 - Dichlorophenoxyacetic Acid[OL].[ 4 March 2011] http://en.paper.edu.cn/en_releasepaper/content/4412461 |
9. An Amperometric Enzyme Sensor Based on Poly-thionine Modified Platinum Electrode for the Detection of Indole-3-acetic Acid | |||
HUANG Lening,WANG Ruozhong,HUANG Zhigang,XIA Shitou,LI Hesong,XIAO Langtao | |||
Biology 04 March 2011 | |||
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Abstract:An electrochemical amperometric enzyme sensor based on poly-thionine modified platinum electrode for the detection of indole-3-acetic acid (IAA) was proposed in this paper. The new sensor was developed mainly according to the oxidation reaction of IAA catalyzed by horseradish peroxidase (HRP). Since this oxidation reaction is substantially the electron transfer process, the current changes when electron transfer reaction occurs on the surface of electrode. Thus, it can provide a general electrochemical method for the direct detection of IAA. The poly-thionine film was produced electrochemically on a platinum electrode in 0.05 M acetate sodium acetate buffer solution (pH 4.5) containing 0.005 M thionine with applied potential of -0.4~1.2 V (versus Ag/AgCl) for about 50 min. After the process of thionine electrodeposit, a blue film of poly thionine was plated on the surface of electrode. HRP was immobilized by means of the glutaraldehyde cross-linking technique. Finally, this HRP-IAA sensor was used to detect IAA. Experimental parameters such as the pH of PBS, HRP incubation temperature and HRP incubation time were optimized. The results indicated that this enzyme sensor had satisfactory linearity with the content of IAA in the range of 1 ng/mL~30 ng/mL with a detection limit of 0.1 ng/mL. | |||
TO cite this article:HUANG Lening,WANG Ruozhong,HUANG Zhigang, et al. An Amperometric Enzyme Sensor Based on Poly-thionine Modified Platinum Electrode for the Detection of Indole-3-acetic Acid[OL].[ 4 March 2011] http://en.paper.edu.cn/en_releasepaper/content/4412367 |
10. DNA methylation in genomes of several annual herbaceous and woody perennial plants of varying ploidy as detected by MSAP | |||
Li Ai,Hu Baoquan,Xue Zhenyi,Chen Li,Wang Weixing,Chen Chengbin,Song Wenqin,Wang Chunguo | |||
Biology 27 December 2010 | |||
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Abstract:Polyploidization is known to accompany altered DNA methylation in higher plants, which plays an important role in gene expression regulation and maintaining genome stability. While the characteristics of DNA methylation in different polyploid plants are still to be elucidated. Here, status of genomic DNA methylation in a series of diploid, triploid, tetraploid annual herbaceous plants (watermelon and Salvia) and woody perennials (pear, poplar and loquat) were explored by methylation specific amplified polymorphism (MSAP) analysis. The results indicated that levels of DNA methylation in triploid watermelon and Salvia were lower than their diploid parents. In triploid poplar and pear, higher levels of DNA methylation were detected, and no significant difference was observed between triploid and tetraploid in all tested materials. Further data analysis suggested that about half of the total detected sites underwent changes of DNA methylation patterns in triploid watermelons and Salvia, as well as an obvious trend towards demethylation. However, the changes of DNA methylation patterns in three triploid woody perennials were only 17.54%~33.40%. This implied that the characteristics of DNA methylation are significantly different during the polyploidization of different plant species. Furthermore, the results suggested that the level of DNA methylation was non-linearly related to the ploidy level, and triploid plants displayed more interesting DNA methylation status. The characteristics and possible functions of DNA methylation in different ploidy series are further discussed. | |||
TO cite this article:Li Ai,Hu Baoquan,Xue Zhenyi, et al. DNA methylation in genomes of several annual herbaceous and woody perennial plants of varying ploidy as detected by MSAP[OL].[27 December 2010] http://en.paper.edu.cn/en_releasepaper/content/4401538 |
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