Transgenic tobacco plants expressing antisense RNA for cytosolic ascorbate peroxidase show increased susceptibility to ozone injury

• Published in: The Plant journal : for cell and molecular biology Vol. 11; no. 6; pp. 1297 - 1305
• Main Authors: Örvar, Björn Lárus, Ellis, Brian E.
• Format: Journal Article
• Language: English
• Published: Osney Mead, Oxford OX2 0EL, UK Blackwell Science Ltd 01-06-1997; Blackwell Science
• Subjects: Biological and medical sciences; Biotechnology; Fundamental and applied biological sciences. Psychology; Genetic engineering; Genetic technics; Methods. Procedures. Technologies; Nicotiana tabacum; Transgenic animals and transgenic plants; Transgenic plants; Oxidative stress; Enzyme; Agrobacterium tumefaciens; Stimulant plant; Ozone; Antisense RNA; Antioxidant; Gene expression; Nicotiana tabacum; Transfection; Enzymatic activity; Dicotyledones; Angiospermae; Bacteria; Spermatophyta; Transgenic plant; Rhizobiaceae; Solanaceae; Oxidoreductases
• DOI: 10.1046/j.1365-313X.1997.11061297.x
• EISSN: 1365-313X
• ISSN: 0960-7412

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.