Construction and Functional Analysis of a Synthetic Wound-and Hormone-inducible Promoter ocs/mas / 中国生物工程杂志

ABSTRACT

The use of optimal regulatory sequences for simultaneous expression of the transgenes might play a significant role in engineering plants with increased disease and insect resistance.The plant expression vector pOMS-GUS,which contained the GUS gene under the control of a chimeric promoter based upon the mannopine synthase(mas)promoter and the octopine synthase(ocs)enhancer,was constructed.Used as control,another vector pMAS-GUS,carried the GUS gene driven by only the mas promoter.The two vectors were introduced into tobacco plants by Agrobacterium-mediated transformation.Fluorometric assays for GUS activity and reverse transcription-polymerase chain reaction(RT-PCR)analysis revealed that GUS gene expressed weakly with untreated transgenic tobacco while the level of GUS activity increased steadily after 1 h subjected to wounding.The expression of the mas and ocs/mas promoters was induced a further 1.8-fold and 5.7-fold,respectively.SA(1 mmol/L)or MJ(250 ?mol/L)treatment also caused a large induction of the ocs/mas chimeric promoter;And the application of SA in combination with MJ(1 mmol/LSA & 250 ?mol/L MJ)produced an additive effect that exceeded the wounding response.The results showed that the ocs/mas chimeric promoter is a strong inducible promoter that can be activated by various stresses.The chimeric promoter should have utility in development of disease and insect resistant transgenic crops.