Functional Analysis Of Wheat TaASR2-B Gene In Seed Germination

The normal process of higher plant development includes seed germination,growth and senescence,which require the regulation of many genes.The ASRs(Abscisic acid,stress,ripening-induced)is a small plant specific gene family that was first identified in tomato in 1993.ASRs response to ABA,stress,fruit ripening and other processes.ASRs crosstalk with ABA,sugar signaling pathways and others,thus affecting plant growth and development.In order to further explore the functions of ASRs,a member of ASRs,TaASR2-B,previously cloned in this laboratory,was transformed into Arabidopsis thaliana.During seed germination,it was found that the transgenic lines germinated earlier than the wild type.In this study,the mechanism of TaASR2-B possibly affecting seed germination was investigated.The main results are as follows:(1)The bioinformatics analysis showed that the TaASR2-B was hydrophilic,which had he conserved structural domain ABA_WDS of ASR family,and was most closely elated to BdASR5 from Brachypodium distachyon(L.)Beauv.and OsASR2 from ryza sativa.(2)The result of organ specificity analysis showed that TaASR2-B was expressed at elative higher level in the roots of four-leaf stage seedlings,and subcellular ocalization showed that TaASR2-B was expressed in the whole cell.(3)Transgenic lines of A.thaliana expressing TaASR2-B were successfully obtained using the method of Agrobacterium-mediated genetic transformation method.The seeds of transgenic lines on 1/2 MS medium with 7% glucose germinated earlier and were relatively less sensitive to high concentration of glucose compared to wild type control.(4)Genes expression and the physiological index analyses showed that the expression of sugar-or ABA-related genes and the ABA content in TaASR2-B-expressing A. thaliana were relatively lower.(5)Vectors of pHIS2-AtABI4-CE1,pHIS2-TaABI4-CE1,pGADT7-TaASR2-B and pBI121-AtPBI4-Promoter-GUS were constructed.Yeast one-hybrid assays showed that TaASR2-B could interact with CE1 in the ABI4 promoter and and GUS staining showed that TaASR2-B could inhibit the expression of ABI4 promoter.This research not only found a new function of the wheat ASRs,but also laid a foundation for further investigation of ASRs function.