Table II.

Antioxidant enzyme activities assayed at 14°C after extraction from maize leaves harvested from the field on May 16, May 23, and June 26, 1995.

ParameterActivity
Per unit of areaPer unit of Chl1-a
May 16 (first leaf)May 23 (third leaf)June 26 (sixth leaf)May 16 (first leaf)May 23 (third leaf)June 26 (sixth leaf)
μmol m−2s−1 μmol mg−1 chl s−1
APX78.2  ± 10.283.8  ± 7.060.4  ± 10.40.81  ± 0.110.58  ± 0.050.22  ± 0.04
DHAR4.4  ± 1.38.7  ± 1.3All nonenzymic0.046  ± 0.0100.060  ± 0.001All nonenzymic
(0.130  ± 0.0030(5 × 10−4  ± 1 × 10−5)
GTR5.1  ± 0.14.8  ± 1.23.8  ± 0.80.053  ± 0.0010.033  ± 0.0080.014  ± 0.003
MDHAR8.6  ± 0.58.8  ± 1.17.2  ± 1.60.090  ± 0.0050.061  ± 0.0080.026  ± 0.006
units m−2s−1 units mg−1 chl s−1
SOD45.6  ± 9.249.2  ± 2.652.6  ± 11.40.48  ± 0.100.34  ± 0.020.19  ± 0.04

Data are the means ± se of four independent replicates.

    • F1-a Chl, Chlorophyll.