title: Influence of over-expression of cytosolic aspartate aminotransferase on amino acid metabolism and defence responses against Botrytis cinerea infection in Arabidopsis thaliana.
abstract: Arabidopsis possesses several genes encoding aspartate aminotransferase, which catalyzes the bidirectional conversion of aspartate into glutamate. These amino acids together with asparagine and glutamine play an important role in N storage and distribution. In addition, they act as precursors for other amino acids. The gene encoding cytosolic aspartate aminotransferase, Asp2, was found to be induced upon infection with the necrotrophic pathogen Botrytis cinerea in Arabidopsis. Asp2 over-expression lines and a T-DNA insertion mutant were used to study the role of aspartate aminotransferase in Arabidopsis defence responses. Over-expression of Asp2 led to changes in aspartate content and aspartate-derived amino acids. The Asp2 knockout mutant was also slightly affected in its amino acid composition. Under standard growth conditions, the Asp2 transgenic lines did not show morphological changes in comparison with the wild-type. However, transgenic lines with the highest Asp2 expression displayed more spreading lesions when infected with B. cinerea. We discuss how this gene involved in amino acid metabolism might interact with plant defence responses.
authors.affiliation: Laboratory of Plant Genetics, Institute for Molecular Biology and Biotechnology, Vrije Universiteit Brussel (VUB), Pleinlaan 2, B-1050 Brussels, Belgium.
authors.forename: Sigrid
authors.initials: S
authors.lastname: Brauc
authors.forename: Eline
authors.initials: E
authors.lastname: De Vooght
authors.forename: Martine
authors.initials: M
authors.lastname: Claeys
authors.forename: Monica
authors.initials: M
authors.lastname: Höfte
authors.forename: Geert
authors.initials: G
authors.lastname: Angenon
mesh_terms: D000596:Amino Acids / Q000032:analysis / Q000378:metabolism*; D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics / Q000378:metabolism* / Q000382:microbiology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D024443:Aspartate Aminotransferase, Cytoplasmic / Q000235:genetics / Q000378:metabolism*; D020171:Botrytis / Q000276:immunology / Q000502:physiology*; D015870:Gene Expression; D018506:Gene Expression Regulation, Plant; D016254:Mutagenesis, Insertional; D010935:Plant Diseases / Q000276:immunology / Q000382:microbiology*; D057865:Plant Immunity; D018515:Plant Leaves / Q000201:enzymology / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000201:enzymology / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D011392:Proline / Q000032:analysis / Q000378:metabolism; D017384:Sequence Deletion
chemical_list: D000596:Amino Acids; D029681:Arabidopsis Proteins; D011392:Proline; D024443:Aspartate Aminotransferase, Cytoplasmic