The Arabidopsis-accelerated cell death Gene ACD1 is Involved in Oxygenation of Pheophorbide a : Inhibition of the Pheophorbide a Oxygenase Activity does not Lead to the "Stay-Green" Phenotype in Arabidopsis

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Author(s)

    • Tanaka Ryouichi TANAKA Ryouichi
    • Institute of Low Temperature Science, Hokkaido University, and Core Research of Science and Technology (CREST), Japan Science and Technology Corporation (JST)
    • Hirashima Masumi HIRASHIMA Masumi
    • Institute of Low Temperature Science, Hokkaido University, and Core Research of Science and Technology (CREST), Japan Science and Technology Corporation (JST)
    • TANAKA Ayumi
    • Institute of Low Temperature Science, Hokkaido University, and Core Research of Science and Technology (CREST), Japan Science and Technology Corporation (JST)

Abstract

Oxygenation of pheophorbide a is a key step in chlorophyll breakdown. Several biochemical studies have implicated that this step was catalyzed by an iron-containing and ferredoxin-dependent monooxygenase, pheophorbide a oxygenase (PaO). It has been proposed that inhibition of its activity arrests the chlorophyll breakdown and leads to the "stay-green" phenotype. We searched the Arabidopsis genome for a possible PaO-encoding gene and hypothesized that it has homology to known iron-containing Rieske-type monooxygenase sequences. We identified three such open reading frames, Tic55, ACD1 and ACD1-like. We produced transgenic Arabidopsis plants which expressed antisense RNA as a method to inhibit the expression of these genes. The appearance of these antisense plants were indistinguishable from that of the wild type under illumination. However, after they were kept under darkness for 5 d and again illuminated, the leaves of the antisense ACD1 plants (AsACD1) were bleached. Leaves of AsACD1 accumulated 387 nmol (g FW)(-1) pheophorbide a which corresponded to 60% of chlorophyll a degraded. The rate of decrease in chlorophyll a was not influenced in senesced AsACD1 leaves. These results demonstrated that ACD1 is involved in PaO activity, and its inhibition led to photooxidative destruction of the cell instead of the "stay-green" phenotype.

Journal

  • Plant and Cell Physiology

    Plant and Cell Physiology 44(12), 1266-1274, 2003-12-01

    Oxford University Press

References:  55

Cited by:  4

Codes

  • NII Article ID (NAID)
    10012003491
  • NII NACSIS-CAT ID (NCID)
    AA0077511X
  • Text Lang
    ENG
  • Article Type
    Journal Article
  • ISSN
    00320781
  • NDL Article ID
    6798252
  • NDL Source Classification
    ZR3(科学技術--生物学--植物)
  • NDL Call No.
    Z53-C97
  • Data Source
    CJP  CJPref  NDL  IR 
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