Cloning And Expression Analysis Of Protein Phosphatase 2A Gene TaPP2AbB"-? Promoter In Wheat

Wheat(Triticum aestivum L.)is one of the most important grain crops for human around the world and our country.So wheat production with a stable and high yield plays significant roles for us.But wheat growth and development are impacted by various abiotic stresses in natural environments.Therefore,discovering the mechanism of against abiotic stresses and improving the resistance in wheat are important issues recently.Protein phosphatase 2A(PP2A)is a heterotrimeric protein,consisting of a scaffolding subunit(A),a catalytic subunit(C),and one member of 4 families of regulatory subunits(B).It plays significant roles in the pathway responding to abiotic stresses in plants.In order to find out the expression characteristics of the promoter PB"? for TaPP2AbB"-?,we isolated a full-length sequence of PB"? from genome DNA of a wheat cultivar"Hanxuan 10".We can truly understand the the expression characteristics of the promoter PB"? via bioinformatics analysis,GUS histochemical staining and quantitative fluorometric GUS assay.Our results are mainly as follows:1.Isolated a full-length sequence of PB"a from genome DNA of wheat.Its full lengh is 1899 bp.2.A list of cis-acting elements were identified from the sequence of promoter PB"?,which respond to salt and osmotic stresses,including TATA-box and CAAT-box,EECCRCAH1(-1058?-1052 bp),GCCCORE(-1073?-1068 bp)and MYCCONSE(-1179?-1174 bp)elements.3.The full-length promoter PB"? and five PB"? promoter truncated from 5'-end in different length fused with the report gene ?-glucuronidas(GUS)were got and transformed into Arabidopsis,respectively.4.The histochemical staining results showed that the full-length promoter PB"?,the deletions of PB"?-1545 and PB"?-1389 could drive GUS gene and expressed in shoots and roots of Arabidopsis seedlings.The active region of PB"? promoter located in the interval of-1389?-946 bp.5.The result of quantitative fluorometric GUS assay showed that only PB"?,PB"?-1545 and PB"?-1389 could be up-regulated expression by salt and osmotic stresses in the transgenic Arabidopsis lines.The present research revealed the active region of PB"? promoter responding to salt and osmotic stresses.The results contribute a basis and technical support to improve abiotic stress resistance in crop plants by selecting a suitable gene promoter of related genes.