Overexpression of Brassica campestris BcICE1 gene increases abiotic stress tolerance in tobacco.

Abstract In this study, a cDNA of ICE1 (inducer of CBF expression 1) gene, named BcICE1 , was isolated from Brassica campestris 'Longyou 6'. The deduced protein has 499 amino acids containing a typical bHLH domain and is highly identical with AtICE1 (85.9%) from Arabidopsis thaliana. BcICE1 is located in the nucleus. The activities of SOD, CAT, POD, and APX and the transcriptional levels of SOD , CAT , and POD genes were higher in BcICE1-transgenic tobacco than in wild-type (WT) tobacco under cold stress. Compared with WT tobacco, proline, soluble sugar, and chlorophyll were enhanced, whereas malondialdehyde and relative conductivity were decreased in BcICE1-transgenic tobacco. The overexpression of BcICE1 in tobacco increased the expression of CBF1 , CBF2 , and other stress-related genes. Moreover, under salt and PEG (25%) stress, the activities of APX and GPX and content of soluble sugar and chlorophyll in BcICE1-transgenic tobacco were higher than those in WT tobacco. Our results suggest that BcICE1 plays an important role in the response to abiotic stress. Highlights • We identified cDNA of the BcICE1 gene from Brassica campestris. • BcICE1 is localized in the nucleus. • Overexpression of BcICE1 increases antioxidant enzyme activity in tobacco. • Overexpression of BcICE1 improves abiotic stress resistance of transgenic tobacco. • Overexpression of BcICE1 alters the expression of antioxidant enzyme genes and stress response genes in tobacco. [ABSTRACT FROM AUTHOR]