Glutamate:Glyoxylate aminotransferase modulates amino acid content during photorespiration

Daisuke Igarashi, Hiroko Tsuchida, Mitsue Miyao, Chieko Ohsumi

研究成果: Article査読

73 被引用数 (Scopus)


In photorespiration, peroxisomal glutamate:glyoxylate aminotransferase (GGAT) catalyzes the reaction of glutamate and glyoxylate to produce 2-oxoglutarate and glycine. Previous studies demonstrated that alanine aminotransferase-like protein functions as a photorespiratory GGAT. Photorespiratory transamination to glyoxylate, which is mediated by GGAT and serine glyoxylate aminotransferase (SGAT), is believed to play an important role in the biosynthesis and metabolism of major amino acids. To better understand its role in the regulation of amino acid levels, we produced 42 GGAT1 overexpression lines that express different levels of GGAT1 mRNA. The levels of free serine, glycine, and citrulline increased markedly in GGAT1 overexpression lines compared with levels in the wild type, and levels of these amino acids were strongly correlated with levels of GGAT1 mRNA and GGAT activity in the leaves. This accumulation began soon after exposure to light and was repressed under high levels of CO2. Light and nutrient conditions both affected the amino acid profiles; supplementation with NH4NO3 increased the levels of some amino acids compared with the controls. The results suggest that the photorespiratory aminotransferase reactions catalyzed by GGAT and SGAT are both important regulators of amino acid content.

ジャーナルPlant physiology
出版ステータスPublished - 2006 11

ASJC Scopus subject areas

  • 生理学
  • 遺伝学
  • 植物科学


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