Preferential Decay of the CF1-ε Subunit Induces Thylakoid Uncoupling in Wild Watermelon Under Drought Stress

  • Kaori Kohzuma
  • Kinya Akashi
  • Yuri Munekage
  • Satoko Sanda
  • Tohru Hisabori
  • Akiho Yokota

Abstract

Photosynthetic energy conversion in plants involves the formation of a proton gradient across thylakoid membranes, but the mechanisms for balancing the membrane potential have been poorly elucidated. We found that drought stress induces selective decomposition of the ε subunit in the CFoCF1 ATP synthase. Thylakoid membranes from stressed leaves showed reduced efficiencies for proton gradient formation and energy coupling, but addition of the recombinant ε subunit significantly suppressed their “leaky” property. We conclude that the selective decomposition of the e subunit induces partial uncoupling of thylakoid membranes under drought, and hence contributes to the avoidance of over-acidification in the thylakoid lumen under excess light conditions.

Keywords

ATP synthase ε subunit thylakoid membrane proton leakage drought/excess light stresses 

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Copyright information

© Springer Science + Business Media, B.V. 2008

Authors and Affiliations

  • Kaori Kohzuma
    • 1
  • Kinya Akashi
    • 1
  • Yuri Munekage
    • 1
  • Satoko Sanda
    • 1
  • Tohru Hisabori
    • 2
    • 3
  • Akiho Yokota
    • 1
  1. 1.Graduate School of Biological SciencesNara Institute of Science and Technology (NAIST)NaraJapan
  2. 2.Chemical Resources Laboratory Tokyo Institute of TechnologyYokohamaJapan
  3. 3.ATP System ProjectERATO, JSTYokohamaJapan

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