Abstract:It has important significance for transgenic resistance research to clone and validate endogenous inducible promoters in response to abiotic stresses,and use to construct inducible expression vectors.In this study,the sequence of the late embryogenesis abundant late gene (MGL3) promoter (pMGL3) was cloned from maize according to bioinformatics analysis.After analysis for abiotic stress-responsive elements and abiotic response by quantitative real-time PCR,we used this sequence to construct expression vector of the reporter gene GUS,and used to transform maize calli by biolistic method.The promotion activity of the pMGL3 promoter under abiotic stress was validated by GUS staining.In addition,the different cis-acting elements was removed according to promoter sequence analysis,used to construct expression vectors of the reporter gene GUS,and transform tobacco discs by Agrobacterium mediation,in order to determine the shortest active sequence of the pMGL3 promoter.The results showed that the pMGL3 promoter is 1 554 bp long,containing multiple regulatory elements in response to abiotic stress.The expression of the MGL3 gene is increased under the stress of drought,high salt and low temperature,and induction of abscisic acid and ethylene.The calli transformed by the GUS gene under control of the pMGL3 promoter showed promotion activity under high osmotic,high salt,low temperature stresses,and abscisic acid induction.However,it kept promotion activity when truncated to as short as 325 bp.These results indicated that the pMGL3 promoter has promotion activity in response to abiotic stresses,and can be applied to maize transgenic studies for abiotic tolerance after further validation for its mechanism.