Wound-induced deposition of polyphenols in transgenic plants overexpressing peroxidase

Journal Article · Sat Jun 01 00:00:00 EDT 1991 · Plant Physiology; (United States)

DOI:https://doi.org/10.1104/pp.96.2.577· OSTI ID:7222106

Lagrimini, L M ^[1]

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1. Ohio State Univ., Columbus (United States)

Tobacco (Nicotiana tabacum) plants transformed with a chimeric tobacco anionic peroxidase gene have previously been shown to synthesize high levels of peroxidase in all tissues throughout the plant. One of several distinguishable phenotypes of transformed plants is the rapid browning of pith tissue upon wounding. Pith tissue from plants expressing high levels of peroxidase browned within 24 hours of wounding, while tissue from control plants did not brown as late as 7 days after wounding. A correlation between peroxidase activity and wound-induced browning was observed, whereas no relationship between polyphenol oxidase activity and browning was found. The purified tobacco anionic peroxidase was subjected to kinetic analysis with substrates which resemble the precursors of lignin or polyphenolic acid. The purified enzyme was found to readily polymerize phenolic acids in the presence of H{sub 2}O{sub 2} via a modified ping-pong mechanism. The percentage of lignin and lignin-related polymers in cell walls was nearly twofold greater in pith tissue isolated from peroxidase-overproducer plants compared to control plants. Lignin deposition in wounded pith tissue from control plants closely followed the induction of peroxidase activity. However, wound-induced lignification occurred 24 to 48 hours sooner in plants overexpressing the anionic peroxidase. This suggests that the availability of peroxidase rather than substrate may delay polyphenol deposition in wounded tissue.

• DOE Contract Number: FG02-89ER14004
• OSTI ID: 7222106
• Journal Information: Plant Physiology; (United States), Vol. 96:2; ISSN 0032-0889
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
NICOTIANA
ENZYME ACTIVITY
PEROXIDASES
BIOLOGICAL FUNCTIONS
POLYPHENOLS
BIOCHEMICAL REACTION KINETICS
CELL WALL
HYDROGEN PEROXIDE
LIGNIN
POLYMERS
RECOMBINANT DNA
WOUNDS
AROMATICS
CARBOHYDRATES
CELL CONSTITUENTS
DNA
ENZYMES
HYDROGEN COMPOUNDS
HYDROXY COMPOUNDS
INJURIES
KINETICS
MAGNOLIOPHYTA
MAGNOLIOPSIDA
NUCLEIC ACIDS
ORGANIC COMPOUNDS
OXIDOREDUCTASES
OXYGEN COMPOUNDS
PEROXIDES
PHENOLS
PLANTS
POLYSACCHARIDES
PROTEINS
REACTION KINETICS
SACCHARIDES
550200* - Biochemistry