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Peroxidase and polyphenol oxidase activities in Cyperus esculentus leaves following glyphosate applications
Author(s) -
Cañal María Jesús,
Tamés Ricardo Sánchez,
Fernández Belén
Publication year - 1988
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.1988.tb04952.x
Subject(s) - peroxidase , cyperus , glyphosate , polyphenol oxidase , glycine , chemistry , enzyme assay , catechol oxidase , botany , proline , polyphenol , food science , enzyme , biology , biochemistry , antioxidant , agronomy , amino acid
Following a 2‐week treatment with glyphosate [N‐(phosphonomethyl)glycine] changes in peroxidase (EC 1.11.1.7) and polyphenol oxidase (PPO; EC 1.14.18.1) activities of yellow nutsedge ( Cyperus esculentus L.) plants, were determined. Glyphosate caused significant increases of both activities. Isoelectric focusing gave 3 species (F 1 , F 2 and F 3 ) of peroxidase activity, at pl 3.8, 4.4 and 4.8, and 4 species (F a , F b , F c and F d ) of PPO activity at pl 7.0, 7.5, 7.8 and 9.5. The activity of the 4 active forms of PPO increased with increasing glyphosate dose up to 10 −2 M . The effect of the herbicide on the 3 fractions with peroxidase activity was to change their relative activities. Highest F 1 activity was found in control plants whereas the F 2 fraction was the predominant form in the plants treated with glyphosate at 10 −2 M and the highest F 3 activity occurred in plants treated with 5 × 10 −3 M glyphosate. The increased PPO activity could produce phytotoxic o ‐quinones, and variations in peroxidase isoenzymes activity could enhance isoperoxidases with lignin biosynthetic activity.