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Author Martin, Antoine ♦ Lee, Judy ♦ Kichey, Thomas ♦ Gerentes, Denise ♦ Zivy, Michel ♦ Tatout, Christophe ♦ Dubois, Frédéric ♦ Balliau, Thierry ♦ Valot, Benoît ♦ Davanture, Marlène ♦ Tercé-Laforgue, Thérèse ♦ Quilleré, Isabelle ♦ Coque, Marie ♦ Gallais, André ♦ Gonzalez-Moro, María-Begoña ♦ Bethencourt, Linda ♦ Habash, Dimah Z. ♦ Lea, Peter J. ♦ Charcosset, Alain ♦ Perez, Pascual ♦ Murigneux, Alain ♦ Sakakibara, Hitoshi ♦ Edwards, Keith J. ♦ Hirel, Bertrand
Source World Health Organization (WHO)-Global Index Medicus
Content type Text
Publisher American Society of Plant Biologists
File Format HTM / HTML
Language English
Difficulty Level Medium
Subject Domain (in DDC) Computer science, information & general works ♦ Library & information sciences ♦ Natural sciences & mathematics ♦ Chemistry & allied sciences ♦ Life sciences; biology ♦ Physiology & related subjects ♦ Biochemistry ♦ Genetics and evolution ♦ Natural history of organisms ♦ Technology ♦ Medicine & health ♦ Human anatomy, cytology, histology ♦ Human physiology ♦ Pharmacology and therapeutics ♦ Diseases ♦ Manufacture for specific uses ♦ Precision instruments & other devices
Subject Domain (in MeSH) Cells ♦ Plant Structures ♦ Anatomy ♦ Eukaryota ♦ Organisms ♦ Enzymes and Coenzymes ♦ Amino Acids, Peptides, and Proteins ♦ Nucleic Acids, Nucleotides, and Nucleosides ♦ Chemicals and Drugs ♦ Investigative Techniques ♦ Analytical, Diagnostic and Therapeutic Techniques and Equipment ♦ Chemical Phenomena ♦ Metabolism ♦ Genetic Phenomena ♦ Biological Sciences ♦ Natural Science Disciplines ♦ Physical Sciences ♦ Information Science ♦ Information Science
Subject Keyword Discipline Botany ♦ Cytosol ♦ Enzymology ♦ Cereals ♦ Economics ♦ Glutamate-ammonia Ligase ♦ Metabolism ♦ Isoenzymes ♦ Zea Mays ♦ Amino Acid Sequence ♦ Base Sequence ♦ Gene Expression Regulation, Enzymologic ♦ Gene Expression Regulation, Plant ♦ Genome, Plant ♦ Genetics ♦ Chemistry ♦ Isolation & Purification ♦ Molecular Sequence Data ♦ Mutagenesis, Insertional ♦ Mutation ♦ Phenotype ♦ Phloem ♦ Plant Leaves ♦ Cytology ♦ Ultrastructure ♦ Plant Roots ♦ Plant Shoots ♦ Protein Subunits ♦ Protein Transport ♦ Proteomics ♦ Rna, Messenger ♦ Transcription, Genetic ♦ Xylem ♦ Journal Article ♦ Research Support, Non-u.s. Gov't
Abstract The roles of two cytosolic maize glutamine synthetase isoenzymes (GS1), products of the Gln1-3 and Gln1-4 genes, were investigated by examining the impact of knockout mutations on kernel yield. In the gln1-3 and gln1-4 single mutants and the gln1-3 gln1-4 double mutant, GS mRNA expression was impaired, resulting in reduced GS1 protein and activity. The gln1-4 phenotype displayed reduced kernel size and gln1-3 reduced kernel number, with both phenotypes displayed in gln1-3 gln1-4. However, at maturity, shoot biomass production was not modified in either the single mutants or double mutants, suggesting a specific impact on grain production in both mutants. Asn increased in the leaves of the mutants during grain filling, indicating that it probably accumulates to circumvent ammonium buildup resulting from lower GS1 activity. Phloem sap analysis revealed that unlike Gln, Asn is not efficiently transported to developing kernels, apparently causing reduced kernel production. When Gln1-3 was overexpressed constitutively in leaves, kernel number increased by 30%, providing further evidence that GS1-3 plays a major role in kernel yield. Cytoimmunochemistry and in situ hybridization revealed that GS1-3 is present in mesophyll cells, whereas GS1-4 is specifically localized in the bundle sheath cells. The two GS1 isoenzymes play nonredundant roles with respect to their tissue-specific localization.
Description Country affiliation: France
Author Affiliation: Martin A ( Unité de Nutrition Azotée des Plantes UR511, Institut National de la Recherche Agronomique, F-78026 Versailles Cedex, France.)
ISSN 10404651
Educational Role Student ♦ Teacher
Age Range above 22 year
Educational Use Reading ♦ Research ♦ Self Learning
Interactivity Type Expositive
Education Level UG and PG
Learning Resource Type Article
Publisher Date 2006-11-01
Publisher Place United States
e-ISSN 1531298X
Volume Number 18
Issue Number 11

Source: WHO-Global Index Medicus