Ectopic expression of a cold-responsive CuZn superoxide dismutase gene, SodCc1, in transgenic rice (Oryza sativa L.)

Abstract

A cytosolic antioxidant enzyme gene, SodCc1, encoding CuZn superoxide dismutase was characterized from rice. SodCc1 mRNA was up-regulated by cold (4°C and 12°C) and by abscisic acid (ABA) treatment. Transgenic rice plants of Ubi:SodCc1 were generated and overexpression of SodCc1 was confirmed at both transcriptional and translational levels. A stress tolerance test via chlorophyll fluorescence at the seedling stage showed no enhanced tolerance by Ubi:SodCc1 plants to cold or methyl-viologen-induced oxidative stress, but they were slightly resistant to drought. Our wilting assay demonstrated no improvement in tolerance to either cold or drought, indicating that cytosolic SodCc1 might not be significantly involved in conferring such tolerances in rice.