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Transgenic tobacco plants expressing antisense RNA for cytosolic ascorbate peroxidase show increased susceptibility to ozone injury
Author(s) -
Örvar Björn Lárus,
Ellis Brian E.
Publication year - 1997
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1046/j.1365-313x.1997.11061297.x
Subject(s) - apx , peroxidase , antioxidant , transgene , ascorbic acid , oxidative stress , genetically modified crops , chemistry , biochemistry , biology , enzyme , food science , gene
Ascorbate peroxidase (APX), as a participant in the ascorbate—glutathione cycle, has been suggested to be a particularly important antioxidant enzyme in helping plants survive oxidative stress, but direct evidence for this has not been reported. We demonstrate that expressing antisense RNA comprising 45% of the 3′‐coding region of the tobacco cytosolic APX, can reduce significantly both the endogenous APX mRNA levels and the APX catalytic activity in transgenic tobacco plants. Those transgenic plants showing a reduction in both endogenous APX mRNA levels and extractable APX activity display a significant increase in ozone injury following high‐level ozone exposure. Lower‐level ozone exposure reveals even more drastic differences between the antisense and control plants, suggesting that even a partial loss of APX function in oxidative defence cannot be fully compensated for by other antioxidant measures.