Isolation of Brassica napus MYC2 gene and analysis of its expression in response to water deficit stress

Manipulation of stress related transcription factors to improve plant stress tolerance is a major goal of current biotechnology researches. MYC2 gene encodes a key stress-related transcription factor involved in Jasmonate (JA) and abscisic acid (ABA) signaling pathways in Arabidopsis. Brassica napus, as a globally important oilseed crop, is a close relative of Arabidopsis.  In the present study, a 960bp cDNA fragment of B. napus MYC2 (BnMYC2) was isolated, cloned and sequenced. The deduced amino acid sequence of the BnMYC2 cDNA fragment showed high homology with Arabidopsis thaliana MYC2 and the putative Brassica oleracea MYC2, implying the conserved functions among these orthologous genes. The expression analysis by a semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) revealed that BnMYC2 is a drought inducible gene. A different expression profile of BnMYC2 was observed between drought tolerant and sensitive B. napus cultivars. The drought tolerant cultivar showed a higher accumulation of BnMYC2 transcript in response to water deficit stress during the studied time course. This result indicates that BnMYC2 may contribute to drought tolerance in B. napus.