NORFLURAZON-TOLERANT DWARF MUTANTS OF ARABIDOPSIS AS A MODEL FOR STUDYING PLANT-RESISTANCE TO OXIDATIVE STRESS

Norflurazon-tolerant mutants er1-1, er1-3, er2, and na were obtained b y screening lines from a genetic collection of Arabidopsis thaliana (L .) Heynh. on a selective medium containing norflurazon (NF), an inhibi tor of carotenoid biosynthesis. These mutants were characterized by a dwarf phenotype and differed in the activities of enzymes that scaveng e active oxygen species (peroxidase, glutathione dehydrogenase, glutat hione reductase, and superoxide dismutase). The er1-3 mutant had a hig her ABA content, and germination of the er2 mutant seeds displayed enh anced sensitivity to this hormone. It is concluded that NF-tolerant mu tants of Arabidopsis present a convenient model for studying the role of phytohormones in the induction of plant adaptive response to oxidat ive stress.