biologia plantarum

Biologia plantarum 50:383-388, 2006 | DOI: 10.1007/s10535-006-0053-x

Differential antioxidant responses in catalase-deficient maize mutants exposed to norflurazon

S. Jung^1,*, S. U. Chon¹, Y. I. Kuk¹

¹ School of Agricultural Biotechnology and Center for Agricultural Biomaterials, Seoul National University, Seoul, Korea

Maize catalase (CAT) mutants lacking in CAT isozymes were used to investigate the response of CAT and superoxide dismutase (SOD) to norflurazon (NF) caused oxidative stress in 18-d post-pollination scutella. NF treatment caused an increase in malonyldialdehyde content, which is an indicator of oxidative stress, and a decrease in a content of photoprotectant carotenoids in the scutella. CAT activity decreased greatly with increasing NF concentration in standard maize line (W64A) and CAT-2 null mutant (WA10C), however, it remained relatively constant in CAT-2/CAT-3 double null mutant (WDN10). Cat1 transcript increased in the NF-treated scutella of W64A and WDN10, with a greater Cat1 transcript in WDN10, whereas Cat2 transcript decreased in the NF-treated scutella of all lines examined. In all lines, SOD activities were not changed noticeably at various NF concentrations. In the scutella of W64A, Sod4A decreased in response to NF but the other Sod transcript contents were unchanged. The CAT-deficient mutants reacted with raised transcripts of Sod1, Sod3, Sod4 or Sod4A.

Keywords: carotenoids; catalase; oxidative stress; superoxide dismutase; Zea mays

Subjects: carotenoids; catalase; maize; malonyldialdehyde; mutagenesis, mutants; norflurazon; nutrient medium, Murashige and Skoog; superoxide dismutase (SOD); Zea mays

Received: August 22, 2003; Accepted: September 15, 2005; Published: September 1, 2006  Show citation