Reactive oxygen species from chloroplasts contribute to 3-acetyl-5-isopropyltetramic acid-induced leaf necrosis of Arabidopsis thaliana.
3-Acetyl-5-isopropyltetramic acid (3-AIPTA), a derivate of tetramic acid, is responsible for brown leaf-spot disease in many plants and often kills seedlings of both mono- and dicotyledonous plants. To further elucidate the mode of action of 3-AIPTA, during 3-AIPTA-induced cell necrosis, a series of experiments were performed to assess the role of reactive oxygen species (ROS) in this process. When Arabidopsis thaliana leaves were incubated with 3-AIPTA, photosystem II (PSII) electron transport beyond Q(A) (the primary plastoquinone acceptor of PSII) and the reduction of the end acceptors at the PSI acceptor side were inhibited; this was followed by increase in charge recombination and electron leakage to O(2), resulting in chloroplast-derived oxidative burst. Furthermore, the main antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX) lost their activity. Excess ROS molecules directly attacked a variety of cellular components and subsequently caused electrolyte leakage, lipid peroxidation and cell membrane disruption. Finally, this led to cell destruction and leaf tissue necrosis. Thus, 3-AIPTA-triggered leaf necrosis of Arabidopsis was found to be a result of direct oxidative injury from the chloroplast-originated ROS burst initiated by the inhibition of normal photosynthetic electron transport.
Weed Research Laboratory, Nanjing Agricultural University, Nanjing 210095, China.
Shiguo
S
Chen
Chunyan
C
Yin
Reto Jörg
RJ
Strasser
Govindjee
Chunlong
C
Yang
Sheng
S
Qiang
D000975:Antioxidants / Q000378:metabolism; D017360:Arabidopsis / Q000187:drug effects* / Q000201:enzymology / Q000502:physiology*; D060387:Ascorbate Peroxidases / Q000187:drug effects / Q000378:metabolism; D002374:Catalase / Q000187:drug effects / Q000378:metabolism; D002462:Cell Membrane / Q000187:drug effects; D002470:Cell Survival; D002736:Chloroplasts / Q000187:drug effects / Q000378:metabolism*; D004579:Electron Transport / Q000187:drug effects; D006861:Hydrogen Peroxide / Q000378:metabolism; D015227:Lipid Peroxidation / Q000187:drug effects; D018384:Oxidative Stress / Q000187:drug effects*; D010788:Photosynthesis / Q000187:drug effects; D045332:Photosystem II Protein Complex / Q000187:drug effects; D018515:Plant Leaves / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism*; D036226:Seedlings / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D013482:Superoxide Dismutase / Q000187:drug effects / Q000378:metabolism; D013720:Tenuazonic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology
D000975:Antioxidants; D045332:Photosystem II Protein Complex; D017382:Reactive Oxygen Species; C070660:3-acetyl-5-isopropyltetramic acid; D013720:Tenuazonic Acid; D006861:Hydrogen Peroxide; D060387:Ascorbate Peroxidases; D002374:Catalase; D013482:Superoxide Dismutase