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Perturbation of Auxin Homeostasis Caused by Mitochondrial FtSH4 Gene-Mediated peroxidase.Accumulation Regulates Arabidopsis Architecture

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Molecular Plant 2014年第5期7卷 856-873页

作者： Shengchun Zhang Juelin Wu Dongke Yuan Daowei Zhang Zhigang Huang Langtao Xiao Chengwei Yang Guangdong Key Lab of Biotechnology for Plant Development College of Life Sciences South China Normal University Guangzhou 510631 China Hunan Provincial Key Laboratory of-Phytohormones and Growth Development Hunan Agricultural University Changsha 410128 China

Reactive oxygen species and auxin play important roles in the networks that regulate plant development and morphogenetic changes, However, the molecular mechanisms underlying the interactions between them are poorly understood. This study isolated a mas （More Axillary Shoots） mutant, which was identified as an allele of the mitochondrial AAA-protease AtFtSH4, and characterized the function of the FtSH4 gene in regulating plant development by medi- ating the peroxidase.dependent interplay between hydrogen peroxide （H2Oz） and auxin homeostasis. The phenotypes of dwarfism and increased axillary branches observed in the mas （renamed as ftsh4-4） mutant result from a decrease in the IAA concentration. The expression levels of several auxin signaling genes, including IAA1, IAA2, and IAA3, as well as several auxin binding and transport genes, decreased significantly in ftsh4-4 plants. However, the H202 and peroxidase. levels, which also have IAA oxidase activity, were significantly elevated in ftsh4-4 plants. The ftsh4-4 phenotypes could be reversed by expressing the iaaM gene or by knocking down the peroxidase.genes PRX34 and PRX33. Both approaches can increase auxin levels in the ftsh4-4 mutant. Taken together, these results provided direct molecular and genetic evidence for the interaction between mitochondrial ATP-dependent protease, H2O2, and auxin homeostasis to regulate plant growth and development.

关键词： Arabidopsis thaliana auxin development FtSH4 hydrogen peroxide IAA oxidation peroxidase.

Enzyme-catalyzed reaction of OPD-H_2O_2-HRP voltammetric enzyme-linked immunoassay system

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Science China Chemistry 1998年第4期41卷 345-352页

作者：焦奎孙刚张书圣 Department of Applied Chemistry Qingdao Institute of Chemical Technology Qingdao China

Enzyme catalyzed reaction of o phenylenediamine (OPD) H\-2O\-2 horseradish peroxidase.(HRP) voltammetric enzyme linked immunoassay system has been studied in detail with electrochemical analysis, high performance liquid chromatography (HPLC), ultraviolet/visible (UV/Vis) spectroscopy, infrared (IR) spectroscopy and nuclear magnetic resonance (NMR) spectroscopy. The pure product of H\-2O\-2 oxidizing OPD catalyzed by HRP was prepared with chemical method. The experimental results of voltammetry and HPLC indicate that only one product of enzyme catalyzed reaction has been obtained under the selected enzyme catalyzed reaction conditions. Identifications by UV/Vis spectrum, IR spectrum and 13 C NMR spectrum show that the product is 2,3 diaminophenazine. The processes of the enzyme catalyzed reaction and the electroreduction of the product of the enzyme catalyzed reaction are described.

关键词： o phenylenediamine voltammetry immunoassay enzyme catalyzing horseradish peroxidase.

Deciphering the Enigma of Lignification： Precursor Transport, Oxidation, and the Topochemistry of Lignin Assembly

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Molecular Plant 2012年第2期5卷 304-317页

作者： Chang-Jun Liu Biology Department Brookhaven National Laboratory Upton NY 11973 USA

Plant lignification is a tightly regulated complex cellular process that occurs via three sequential steps： the synthesis of monolignols within the cytosol; the transport of monomeric precursors across plasma membrane; and the oxidative polymerization of monolignols to form lignin macromolecules within the cell wall. Although we have a reasonable understanding of monolignol biosynthesis, many aspects of lignin assembly remain elusive. These include the pre- cursors＇ transport and oxidation, and the initiation of lignin polymerization. This review describes our current knowledge of the molecular mechanisms underlying monolignol transport and oxidation, discusses the intriguing yet least- understood aspects of lignin assembly, and highlights the technologies potentially aiding in clarifying the enigma of plant lignification.

关键词： lignification monolignol transport ABC transporter laccase peroxidase.

Silica nanospheres formation induced by peroxidase.catalyzed phenol polymerization

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Progress in Natural Science:Materials International 2003年第7期 23-26页

作者： FANG Jiangyu, WANG He, CHEN Yang and ZHANG Fusuo (1. College of Resources and Environmental Sciences, China Agricultural University, Beijing 100094, China 2. College of Agronomy, Gansu Agricultural University, Lanzhou 730070, China)

To examine whether lignin-like compound is correlated with silica precipitation in grass, a series of simulated chemical experiments were carried out at ambient temperature and pressure, close to cell wall pH, with phenol polymerization catalyzed by peroxi-dase in silicon solution. The experiments showed that phenol polymer (a kind of lignin-like substance) caused silica nanosphere precipitation similar to those caused by protein in diatom cell wall previously reported by other authors. The sphere diameter varied with different kinds of phenol and the concentrations of phenol and silicon. Silicon precipitation had phenol and silicon saturation effect, meaning that when the concentration ratio of soluble silicon to phenol exceeded a certain value, the amount of silicon precipitation would decrease.

关键词： silicon phenol peroxidase.

Physical, Chemical and Biochemical Changes of Sweetsop （Annona squamosa L.） and Golden Apple （Spondias citherea Sonner） Fruits during Ripening

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Journal of Agricultural Science and Technology(B) 2012年第11期2卷 1148-1157页

作者： Angel Guadarrama Scarlett Andrade Department of Agricultural Botany College of Agriculture Central University of Venezuela Maraeay Aragua 2021 Venezuela

This study aimed at the physical, chemical and biochemical changes during ripening of Sweetsop （Annona squamosa L.） and Golden Apple （Spondias citherea Sonner） fruits during ripening as important features to better understand their postharvest handling. It was carried out physical analysis such as firmness and chemical analysis such as total chlorophyll, total carotenoids, soluble solids, pectins and titrable acidity and biochemical analysis such as pectin methyl esterase, polygalacturonase, cellulase, and peroxidase.and polyphenoloxidase activities in crude extract. Fruits were harvested at different stages of ripening. Experimental design was completely randomized and was carried out analysis of variance and Tukey tests, Total chlorophyll was decreasing in later stages of ripening, total soluble solid contents increased as the fruits ripen, while the acidity expressed percentage of citric acid decreased during fruits ripening. The loss of firmness and soluble solids content increased as the fruit get ripped stage, while the content of pectin decreased. Activity was observed for pectin methyl esterase and polygalacturonase enzymes during all stages of maturation, presenting the highest activity for both enzymes in the mature state. No cellulase activity detected at any stage during the ripening of these fruits. Activity of the enzyme polyphenoloxidase and peroxidase. associated with pulp browning was higher in the last stages of ripening of these fruits. Physical, chemical and biochemical patterns during ripening were different according to fruit species suggesting differential postharvest handling requirements.

关键词： Firmness pectin pectin methyl esterase polygalacturonase peroxidase.