Abstract: In order to explore the effect of plant hormones and environment stress on the expression of Brassica napus ESP (BnESP), a cDNA encoding BnESP was cloned from Zhongshuang No. 9 by homology cloning approach. Sequence analysis showed that BnESP had 343 amino acids, and revealed 99% identity with brassica oleracea ESP and a high homology with nitrile-specific proteins (NSP), MY-binding-like protein (MBP) and JA inducible protein (JIP). Quantitative RT-PCR analysis showed that the expression of BnESP were promptly activated by MeJA and by wound treatment, and suppressed by Benzothiadiazole and by Sclerotinia sclerotiorum. This study suggests that ESP is a JIP and plays an important role in crossing-talk between SA and JA signaling and in the molecular network of oilseed rape response against S. sclerotiorum. Meanwhile, this study can provide a cue for producing health foods through attenuating the expression of ESP in cruciferous plants.

Key words: oilseed rape, epithiospecific protein (ESP), gene cloning, induced expression