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Matthew Herritt, Arun Prabhu Dhanapal, Felix B Fritschi
The photochemical reflectance index (PRI) is determined from canopy spectral reflectance measurements and can provide important information about photosynthesis. The PRI can be used to assess the epoxidation state of xanthophyll pigments, which provides information on nonphotochemical quenching (NPQ) and the amount of energy used for photosynthesis. Genome-wide association analyses were conducted to identify single-nucleotide polymorphisms (SNPs) and genomic loci associated with PRI using data from a soybean [ (L...
July 2016: Plant Genome
Michael Eyer, Benjamin Dainat, Peter Neumann, Vincent Dietemann
Organisms' lifespans are modulated by both genetic and environmental factors. The lifespan of eusocial insects is determined by features of the division of labor, which itself is influenced by social regulatory mechanisms. In the honey bee, Apis mellifera, the presence of brood and of old workers carrying out foraging tasks are important social drivers of ageing, but the influence of young adult workers is unknown, as it has not been experimentally teased apart from that of brood. In this study, we test the role of young workers in the ageing of their nestmates...
November 16, 2016: Experimental Gerontology
Thomas Heine, Kathryn Tucker, Nonye Okonkwo, Berhanegebriel Assefa, Catleen Conrad, Anika Scholtissek, Michael Schlömann, George Gassner, Dirk Tischler
The enantioselective epoxidation of styrene and related compounds by two-component styrene monooxygenases (SMOs) has targeted these enzymes for development as biocatalysts. In the present work, we prepare genetically engineered fusion proteins that join the C-terminus of the epoxidase (StyA) to the N-terminus of the reductase (StyB) through a linker peptide and demonstrate their utility as biocatalysts in the synthesis of Tyrain purple and other indigoid dyes. A single-vector expression system offers a simplified platform for transformation and expansion of the catalytic function of styrene monooxygenases, and the resulting fusion proteins are self-regulated and couple efficiently NADH oxidation to styrene epoxidation...
November 9, 2016: Applied Biochemistry and Biotechnology
Maxim Itkin, Rachel Davidovich-Rikanati, Shahar Cohen, Vitaly Portnoy, Adi Doron-Faigenboim, Elad Oren, Shiri Freilich, Galil Tzuri, Nadine Baranes, Shmuel Shen, Marina Petreikov, Rotem Sertchook, Shifra Ben-Dor, Hugo Gottlieb, Alvaro Hernandez, David R Nelson, Harry S Paris, Yaakov Tadmor, Yosef Burger, Efraim Lewinsohn, Nurit Katzir, Arthur Schaffer
The consumption of sweeteners, natural as well as synthetic sugars, is implicated in an array of modern-day health problems. Therefore, natural nonsugar sweeteners are of increasing interest. We identify here the biosynthetic pathway of the sweet triterpenoid glycoside mogroside V, which has a sweetening strength of 250 times that of sucrose and is derived from mature fruit of luo-han-guo (Siraitia grosvenorii, monk fruit). A whole-genome sequencing of Siraitia, leading to a preliminary draft of the genome, was combined with an extensive transcriptomic analysis of developing fruit...
November 22, 2016: Proceedings of the National Academy of Sciences of the United States of America
Shadi Rahimi, Yu-Jin Kim, Johan Sukweenadhi, Dabing Zhang, Deok-Chun Yang
Ginsenosides, the valuable pharmaceutical compounds in Panax ginseng, are triterpene saponins that occur mainly in ginseng plants. It was shown that in vitro treatment with the phytohormone jasmonic acid (JA) is able to increase ginsenoside production in ginseng plants. To understand the molecular link between JA biosynthesis and ginsenoside biosynthesis, we identified a JA biosynthetic 13-lipoxygenase gene (PgLOX6) in P. ginseng that promotes ginsenoside production. The expression of PgLOX6 was high in vascular bundles, which corresponds with expression of ginsenoside biosynthetic genes...
November 2016: Journal of Experimental Botany
Jinxin Li, Shujie Liu, Juan Wang, Jing Li, Dahui Liu, Jianli Li, Wenyuan Gao
In this work, we selected three fungi strains (Aspergillus niger, Aspergillus flavus and Aspergillus oryzae) as elicitors prepared from mycelium or fermentation broth to improve ginsenosides production in adventitious roots culture. The results showed that ginsenosides production (29.90±4.67mgg(-1)) was significantly enhanced upon elicitation with 200mgL(-1)A. niger elicitor prepared from mycelium, which was 3.52-fold of untreated group. HPLC-ESI-MS(n) analysis was performed, showing that ginsenoside Rb3 was present after treatment with the A...
October 13, 2016: Journal of Biotechnology
Huihong Guo, Rufang Li, Shibiao Liu, Na Zhao, Shuo Han, Mengmeng Lu, Xiaomin Liu, Xinli Xia
Gynostemma pentaphyllum (Thunb.) Makino is a perennial medicinal herb widely distributed in China. This herb contains important medicinal components called gypenosides, which belong to dammarane-type triterpenoid saponins. Squalene epoxidase (SE, EC catalyzes the epoxidation of squalene to form oxidosqualene and is a key regulatory enzyme in triterpenoid saponin biosynthesis. In this study, a SE gene designated as GpSE1 was isolated from G. pentaphyllum leaves. The deduced protein sequence of GpSE1 contained two conserved domains involved in the catalytic function of SE...
October 6, 2016: Plant Physiology and Biochemistry: PPB
Tibor András Rokob
Oxygenation of aromatic rings using O2 is catalyzed by several non-heme carboxylate-bridged diiron enzymes. In order to provide a general mechanistic description for these reactions, computational studies were carried out at the ONIOM(B3LYP/BP86/Amber) level on the non-heme diiron enzyme benzoyl coenzyme A epoxidase BoxB. The calculations revealed four possible pathways for attacking the aromatic ring: a) electrophilic (2e(-)) attack by a bis(μ-oxo)-diiron(IV) species (Q pathway); b) electrophilic (2e(-)) attack via the σ* orbital of a μ-η(2):η(2)-peroxo-diiron(III) intermediate (Pσ* pathway); c) radical (1e(-)) attack via the π*-orbital of a superoxo-diiron(II,III) species (Pπ* pathway); d) radical (1e(-)) attack of a partially quenched diiron(IV) intermediate (Q' pathway)...
September 28, 2016: Journal of the American Chemical Society
Jianli Li, Shujie Liu, Juan Wang, Jing Li, Jinxin Li, Wenyuan Gao
This study reports the best culture conditions for roots growth and accumulation of active components by optimizing the parameters. Glycyrrhiza uralensis adventitious roots metabolites were significantly increased after adding Saccharomyces cerevisiae and Meyerozyma guilliermondii. The highest contents of polysaccharide, glycyrrhizic acid, glycyrrhetinic acid and total flavonoids were obtained in Meyerozyma guilliermondii group, the content of glycyrrhizic acid was 5.3-fold higher than the control. In control and treatment groups, twelve compounds were identified by high performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS),among which, some new compounds have been detected in elicitor groups including 5,7-Dihydroxyflavanone, glycyrrhisoflavanone, licorice saponin J2, uralsaponin B, (3R)-vestitol, uralenol...
September 20, 2016: Biotechnology and Applied Biochemistry
Zhirong Li, Graham Peers, Rachel M Dent, Yong Bai, Scarlett Y Yang, Wiebke Apel, Lauriebeth Leonelli, Krishna K Niyogi
Plants, algae and cyanobacteria need to regulate photosynthetic light harvesting in response to the constantly changing light environment. Rapid adjustments are required to maintain fitness because of a trade-off between efficient solar energy conversion and photoprotection. The xanthophyll cycle, in which the carotenoid pigment violaxanthin is reversibly converted into zeaxanthin, is ubiquitous among green algae and plants and is necessary for the regulation of light harvesting, protection from oxidative stress and adaptation to different light conditions(1,2)...
September 12, 2016: Nature Plants
Jing Xu, Zhigang Li, Haorui Yang, Xiaohong Yang, Cuixia Chen, Hui Li
Violaxanthin de-epoxidase (VDE) has a critical role in the carotenoid biosynthesis pathway, which is involved in protecting the photosynthesis apparatus from damage caused by excessive light. Here, a VDE gene in maize, ZmVDE1, was cloned and shown to have functional domains in common with the gramineous VDE protein. Candidate gene association analysis indicated that no polymorphic sites in ZmVDE1 were significant association with any of the examined carotenoid-related traits at P = 0.05 in an association panel containing 155 maize inbred lines...
2016: Frontiers in Genetics
Qiusheng Kong, Jingxian Yuan, Lingyun Gao, Peng Liu, Lei Cao, Yuan Huang, Liqiang Zhao, Huifang Lv, Zhilong Bie
Rootstocks have comprehensive effects on lycopene accumulation in grafted watermelon fruits. However, little is known about lycopene metabolic regulation in grafted watermelon. To address this problem, parallel changes in lycopene contents and the expression of its metabolic genes were analyzed during the fruit ripening of nongrafted watermelon and watermelon grafted onto bottle gourd, pumpkin, and wild watermelon. Results showed that rootstocks mediated the transcriptional regulations of lycopene accumulation in different ways...
January 1, 2017: Food Chemistry
Ju Yeun Lee, Sei Mee Yoon, Eun Ju Choi, Jinu Lee
Terbinafine is an antifungal agent that selectively inhibits fungal sterol synthesis by blocking squalene epoxidase. We evaluated the effect of terbinafine on gap junctional intercellular communication (GJIC). Fluorescence recovery after photobleaching (FRAP) and I-YFP GJIC assays revealed that terbinafine inhibits GJIC in a reversible and dose-dependent manner in FRT-Cx43 and LN215 cells. Treatment with terbinafine did not affect Cx43 phosphorylation status or intracellular Ca(2+) concentration, well-known action mechanisms of various GJIC blockers...
September 15, 2016: Toxicology and Applied Pharmacology
Heqiang Huo, Isabelle M Henry, Eric R Coppoolse, Miriam Verhoef-Post, Johan W Schut, Han de Rooij, Aat Vogelaar, Ronny V L Joosen, Leo Woudenberg, Luca Comai, Kent J Bradford
Lettuce (Lactuca sativa) seeds exhibit thermoinhibition, or failure to complete germination when imbibed at warm temperatures. Chemical mutagenesis was employed to develop lettuce lines that exhibit germination thermotolerance. Two independent thermotolerant lettuce seed mutant lines, TG01 and TG10, were generated through ethyl methanesulfonate mutagenesis. Genetic and physiological analyses indicated that these two mutations were allelic and recessive. To identify the causal gene(s), we applied bulked segregant analysis by whole genome sequencing...
July 13, 2016: Plant Journal: for Cell and Molecular Biology
Syed Haider, Alan McIntyre, Ruud G P M van Stiphout, Laura M Winchester, Simon Wigfield, Adrian L Harris, Francesca M Buffa
BACKGROUND: Altered metabolism is a hallmark of cancer. However, the role of genomic changes in metabolic genes driving the tumour metabolic shift remains to be elucidated. Here, we have investigated the genomic and transcriptomic changes underlying this shift across ten different cancer types. RESULTS: A systematic pan-cancer analysis of 6538 tumour/normal samples covering ten major cancer types identified a core metabolic signature of 44 genes that exhibit high frequency somatic copy number gains/amplifications (>20 % cases) associated with increased mRNA expression (ρ > 0...
2016: Genome Biology
Animesh Acharjee, Bjorn Kloosterman, Richard G F Visser, Chris Maliepaard
BACKGROUND: In order to find genetic and metabolic pathways related to phenotypic traits of interest, we analyzed gene expression data, metabolite data obtained with GC-MS and LC-MS, proteomics data and a selected set of tuber quality phenotypic data from a diploid segregating mapping population of potato. In this study we present an approach to integrate these ~ omics data sets for the purpose of predicting phenotypic traits. This gives us networks of relatively small sets of interrelated ~ omics variables that can predict, with higher accuracy, a quality trait of interest...
2016: BMC Bioinformatics
Sabrina Gonzalez-Jorge, Payam Mehrshahi, Maria Magallanes-Lundback, Alexander E Lipka, Ruthie Angelovici, Michael A Gore, Dean DellaPenna
Elucidation of the carotenoid biosynthetic pathway has enabled altering the composition and content of carotenoids in various plants, but to achieve desired nutritional impacts, the genetic components regulating carotenoid homeostasis in seed, the plant organ consumed in greatest abundance, must be elucidated. We used a combination of linkage mapping, genome-wide association studies (GWAS), and pathway-level analysis to identify nine loci that impact the natural variation of seed carotenoids in Arabidopsis (Arabidopsis thaliana)...
July 2016: Plant Physiology
Erik Ingmar Hallin, Mahmudul Hasan, Kuo Guo, Hans-Erik Åkerlund
Violaxanthin de-epoxidase (VDE) is a conditionally soluble enzyme located in the thylakoid lumen and catalyses the conversion of violaxanthin to antheraxanthin and zeaxanthin, which are located in the thylakoid membrane. These reactions occur when the plant or algae are exposed to saturating light and the zeaxanthin formed is involved in the process of non-photochemical quenching that protects the photosynthetic machinery during stress. Oversaturation by light results in a reduction of the pH inside the thylakoids, which in turn activates VDE and the de-epoxidation of violaxanthin...
July 2016: Photosynthesis Research
Chengcheng Zhao, Xin Gao, Xinbin Liu, Yong Wang, Shengli Yang, Fengqing Wang, Yuhong Ren
Ginsenosides from the edible and medicinal plant ginseng have demonstrated various pharmacological activities. However, producing ginsenoside efficiently remains a challenge. Engineering metabolic pathways through protein assembly in yeast is a promising way for ginsenoside production. In the biosynthetic pathway of ginsenosides, dammarenediol-II synthase and squalene epoxidase are two key enzymes that determine the production rate of the dammarane-type ginsenoside precursor dammarenediol-II. In this work, a strategy to enhance the biosynthesis of dammarenediol-II in Pichia pastoris was developed by the self-assembly of the two key enzymes via protein-protein interaction...
May 4, 2016: Journal of Agricultural and Food Chemistry
Tsuyoshi Yamamoto, Yuta Tsunematsu, Kodai Hara, Tomohiro Suzuki, Shinji Kishimoto, Hirokazu Kawagishi, Hiroshi Noguchi, Hiroshi Hashimoto, Yi Tang, Kinya Hotta, Kenji Watanabe
Geometric isomerization can expand the scope of biological activities of natural products. The observed chemical diversity among the pseurotin-type fungal secondary metabolites is in part generated by a trans to cis isomerization of an olefin. In vitro characterizations of pseurotin biosynthetic enzymes revealed that the glutathione S-transferase PsoE requires participation of the bifunctional C-methyltransferase/epoxidase PsoF to complete the trans to cis isomerization of the pathway intermediate presynerazol...
May 17, 2016: Angewandte Chemie
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