African Journal of Biotechnology Vol. 6 (5), pp. 516-522, 5 March 2007   

ISSN 1684–5315 © 2007 Academic Journals        

Full Length Research Paper

Isolation, characterization and expression analysis of BrMyb from Erwinia carotovora subsp. Carotovora diseased Chinese cabbage

Song-He Zhang^1,2, Qing Yang¹and Rong-Cai Ma²*

¹College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China.

²Beijing Agro-Biotechnology Research Center, Beijing Academy of Agriculture and Forestry Sciences, Beijing 100089, China.

*Corresponding author. E-mail: marongcai@baafs.net.cn  Fax: 86-10-51503980. Tel: 86-10-51503831.

Accepted 29 December, 2006

Plant MYB Transcription factors play important roles in defense responses. We described here a novel gene BrMyb encoding MYB transcription factor homologue was isolated from Erwinia carotovora subsp. Carotovora (Ecc) pathogens diseased Chinese cabbage (Brassica rapa subsp. pekinensis) and named as BrMyb. The nucleotide sequence of the cloned BrMyb revealed a single open reading frame of 1047 bp coding for 348 amino acids with a theoretical protein size of 48 kDa. The deduced amino acid sequence showed significant homology with Brassica oleracea brassica MYB protein and Arabidopsis thaliana minor MYB protein by 89.2 and 81.2% amino acid sequence identity, respectively. The protein showed significant alignments with a SANT/Myb DNA binding domain in members of MYB family proteins from dicotyledon and monocotyledon. The expression of BrMyb could be detected in developmental leafstalks and enhanced by Ecc infection, injury, methyl jasmonic acid and salicylic acid treatments, respectively. These results suggested that BrMyb might be an old plant gene, and plays roles not only in plant development but also in the response to pathogen infection and other stresses.

Key words: Transcription factor, Erwinia carotovora subsp. carotovora, Brassica rapa subsp. pekinensis, methyl jasmonic acid, salicylic acid.