Genomic cloning and characterization of glutathione reductase gene from Brassica campestris var. Pekinensis

Abstract

We have isolated and characterized a gene encoding cytosolic glutathione reductase from Brassica campestris (B. campestris). The gene (BcgGR1) is presented as a single copy in the B. campestris genome and is composed of 17 exons and 16 introns in the trancribed region with coding sequence beginning in the 2nd exon and ending in the 17th exon. BcgGR1 is expressed strongly in roots and calli, and moderately in stems and leaves. The transcription is strongly induced by various stress treatments including ozone, paraquat, salt, hydrogen peroxide, chilling or ABA but depressed by heat treatment. The transcript level of BcgGR1 is increased significantly at 2 h after the onset of ozone (300 ppb), paraquat (10 muM) or salt (250 mM NaCl) treatments and reached a maximum level by 10-24 h. However, the maximum induction of BcgGR1 is reached at 2-4 h after the onset of hydrogen peroxide (10 mM), chilling (10degreesC) or ABA (1 mM) treatments. The rapid reduction of BcgGR1 transcripts after 4 h in ABA treatment is distinguished from hydrogen peroxide and chilling treatments.