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In tobacco, the two enzymes of nitrogen metabolism, cytosolic glutamine synthetase (GS1; E.C.6.3.1.2) and glutamate dehydrogenase (GDH; E.C.1.4.1.2), are induced during leaf senescence, whereas the chloroplastic glutamine synthetase (GS2; E.C.6.3.1.2) and nitrate reductase (NR; E.C.1.6.1.1) are repressed in the course of ageing. In this report, we showed in discs of fully expanded Nicotiana tabacum L. cv. Xanthi leaves that sucrose (Suc) and amino acids were involved in the regulation of the expression of GS1 and GDH genes. Suc induced the expression of GS1 and repressed that of GDH. Therefore, we concluded that in response to Suc, GS1 behaved as an "early" Senescence Associated Gene (SAG), whereas GDH behaved as a "late" SAG. Moreover, amino acids induced the expression of both genes. Among the amino acids tested as signal molecules, proline (Pro) and glutamate (Glu) were major inducers of GDH and GS1 expression, respectively. Interestingly, an opposite regulation of GS1 and GS2 by Pro and Glu was shown. The contrary effect of Suc on NIA (NR encoding gene) and GDH mRNA accumulation was also emphasized.
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http://dx.doi.org/10.1007/s00425-004-1468-2 | DOI Listing |
J Sci Food Agric
September 2025
Microbial Biotechnology Research Group, School of Life Sciences and Technology, Institut Teknologi Bandung, Bandung, Indonesia.
Background: Secondary fermentation can reduce variability in cocoa bean quality caused by the spontaneous, uncontrolled nature of primary fermentation. However, its optimization remains unexplored. This study evaluated the improvement of secondary fermentation through the combined use of Citrus limon peel and inoculation with Candida tropicalis H1Y4-1 as a starter.
View Article and Find Full Text PDFACS Catal
August 2025
Department of Chemistry, University of Southern California, Los Angeles, California 90089, United States.
Chlorinated hydrocarbons are widely used as solvents and synthetic intermediates, but their chemical persistence can cause hazardous environmental accumulation. Haloalkane dehalogenase from (DhlA) is a bacterial enzyme that naturally converts toxic chloroalkanes into less harmful alcohols. Using a multiscale approach based on the empirical valence bond method, we investigate the catalytic mechanism of 1,2-dichloroethane dehalogenation within DhlA and its mutants.
View Article and Find Full Text PDFFront Immunol
September 2025
Department of Medicine, Division of Hematology, Bioclinicum and Center for Molecular Medicine, Karolinska Institute and Karolinska University Hospital Solna, Stockholm, Sweden.
Background: Metabolic reprogramming is an important hallmark of cervical cancer (CC), and extensive studies have provided important information for translational and clinical oncology. Here we sought to determine metabolic association with molecular aberrations, telomere maintenance and outcomes in CC.
Methods: RNA sequencing data from TCGA cohort of CC was analyzed for their metabolic gene expression profile and consensus clustering was then performed to classify tumors into different groups/subtypes.
Front Microbiol
August 2025
Hans Merensky Chair in Avocado Research, University of Pretoria, Pretoria, South Africa.
Phytophthora root rot caused by the hemibiotrophic oomycete, is a major biotic hindrance in meeting the ever-increasing demand for avocados. In addition, the pathogen is a global menace to agriculture, horticulture and forestry. Phosphite trunk injections and foliar sprays remain the most effective chemical management strategy used in commercial avocado orchards against the pathogen.
View Article and Find Full Text PDFFront Genet
August 2025
Wisconsin National Primate Research Center, University of Wisconsin, Madison, WI, United States.
Introduction: Aging is accompanied by systemic metabolic changes that contribute to disease susceptibility and functional decline. Sex differences in aging have been reported in humans, yet their mechanistic basis remains poorly understood. Due to their physiological similarity to humans, rhesus macaques are a powerful translational model to investigate sex-specific metabolomic aging under controlled conditions.
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