Poster: Metabolic engineering
Abs #
288: Alteration of amino acids contents by over expression of photorespiratory glutamate: glyoxylate aminotransferase (GGAT) gene in Arabidopsis
Glutamate glyoxylate aminotransferase (GGAT) catalyzes the reaction of glutamate and glyoxylate to 2-oxoglutarate and glycine. GGAT plays an essential role in the photorespiratory transamination in the peroxisome. We previously identified a photorespiratory GGAT gene (GGAT1) by analyzing a knockout line of the alanine 2-oxoglutarate aminotransferase (AOAT) -like gene (Igarashi et al. Plant J 33, 975- 2003). To better understand the function of the GGAT1 gene in amino acid metabolism, we obtained many transgenic Arabidopsis plants overexpressing GGAT1 that had various levels of GGAT1 mRNA. The transgenic plants had markedly higher free serine levels, being at maximum 20 times that in the non-transgenic plants. The serine content clearly correlated with the level of GGAT1 mRNA expression and with the GGAT activity. These results suggested that photorespiratory transamination participates in the regulation of amino acid metabolism.
