Thylakoid membrane‐bound ascorbate peroxidase is a limiting factor of antioxidative systems under photo‐oxidative stress

• Yukinori Yabuta

• Takashi Motoki

• Kazuya Yoshimura

• Toru Takeda

• Takahiro Ishikawa

• Shigeru Shigeoka

抄録

To evaluate the physiological importance of thylakoid membrane‐bound ascorbate peroxidase (tAPX) in the active oxygen species‐scavenging system of chloroplasts, the level of tAPX in tobacco plants was altered by expression of the tAPX cDNA in both sense and antisense orientation. The tobacco plants transformed with constructs of antisense tAPXs from spinach and tobacco could not be obtained, suggesting that the suppression of tAPX in higher plants had a severe effect on the growth even   under normal conditions. In contrast, the transgenic tobacco plants (TpTAP‐12) overexpressing tAPX, which had approximately 37‐fold higher activity than that of the wild‐type plants, were generated. The TpTAP‐12 plants showed increased tolerance to oxidative stress caused by application of methylviologen (MV, 50 µ m ) under light intensity (300 and 1600 µE m −2  sec −1 ) and by chilling stress with high light intensity (4°C, 1000 µE m −2  sec −1 ). At 24 h after the MV treatment under illumination at 300 µE m −2  sec −1 , destruction of chlorophyll was observed in the wild‐type plants, but not in the TpTAP‐12 plants. The activities of thiol‐modulated enzymes in the Calvin cycle, the level and redox status of ascorbate (AsA), and the activity of tAPX in the wild‐type plants significantly decreased, while those in the TpTAP‐12 plants were hardly changed. These observations suggest that tAPX is a limiting factor of antioxidative systems under photo‐oxidative stress in chloroplasts, and that the enhanced activity of tAPX functions to maintain the AsA content and the redox status of AsA under stress conditions.

収録刊行物

• The Plant Journal

  The Plant Journal 32 (6), 915-925, 2002-12

  Wiley

キーワード

• Cell Biology
• Plant Science
• Genetics

詳細情報

• CRID: 1363107370299116544
• NII論文ID: 30014609065
• DOI: 10.1046/j.1365-313x.2002.01476.x
• ISSN: 1365313X
• ISSN: 09607412
• ISSN: http://id.crossref.org/issn/09607412
• Web Site: https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1046%2Fj.1365-313X.2002.01476.x
• Web Site: https://onlinelibrary.wiley.com/doi/pdf/10.1046/j.1365-313X.2002.01476.x
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