Cloning And Expression Analysis Of Photoperiod-related Genes TaPIF4 And TaPP2C27 In Wheat(Triticum Aestivum L.)

Photoperiodic response is one of the important factors affecting the flowering time of wheat.In recent years,with the development of molecular biology and epigenetics,the research on the molecular mechanism of photoperiod response in wheat has also made new progress.Many photoperiod-related genes have yet to be further studied.In this study,the differentially expressed genes Ta PIF4 and Ta PP2C27 were screened form the digital gene expression profile of photoperiod development,and their cloning and expression characteristics were studied.At the same time,a plant overexpression vector of Ta PIF4 gene was constructed.The main findings are as follows:1.The Ta PIF4 gene was cloned from Liaochun 10 wheat by reverse transcription PCR.The full-length c DNA of this gene is 1244 bp,its open reading frame(ORF)is 1053 bp,and 350 amino acids are encoded.The g DNA sequence of the Ta PIF4 gene includes 4 exons and 3 introns.The on-line website predicts that the molecular weight of the protein encoded by this gene is 37.96 k Da and the isoelectric point is 5.87.It contains a b HLH conserved domain at the C-terminus,and it is no transmembrane structure and disulfide bond,and it is a structurally unstable hydrophilic protein,which is located in the nucleus.By homologous comparison analysis,Ta PIF4 protein is closest to the PIF4-like protein of Aegilops tauschii.Real time fluorescence quantitative analysis showed that the expression of this gene has circadian rhythm,which is characterized by low expression under light conditions and high expression under dark conditions.It is speculated that Ta PIF4 may be involved in the plant photoperiod response signaling pathway.The expression of Ta PIF4 gene is inhibited by exogenous ABA.It is speculated that this gene may be involved in the ABA regulatory pathway.Under drought conditions,the expression of Ta PIF4 is higher in early stage and is inhibited in later stage,which might be related to photosynthesis.At low temperature,Ta PIF4 begin to express a lot at 24 h,and it may be that low temperature makes the plants produce stress resistance.It is speculated that Ta PIF4 may be involved in plant ABA,drought and low temperature stress signal pathway.2.The Ta PP2C27 gene was cloned from Liaochun 10 wheat by reverse transcription PCR.The full-length c DNA of this gene is 1411 bp,its open reading frame is 1059 bp,and 352 amino acids are encoded.The on-line website predicts that the molecular weight of the protein encoded by this gene is 39.09 k Da and the isoelectric point is 5.01.The protein contains a PP2 Cc conserved domain,and it is no transmembrane structure and disulfide bond,and it is a structurally unstable hydrophilic protein,which is located in the nucleus.Homology analysis showed that PP2C27 protein is conserved among different species,and Ta PP2C27 protein is closest to PP2C27 protein of Aegilops tauschii.The expression characteristics of Ta PP2C27 were analyzed.The expression of Ta PP2C27 gene was specific to tissues and organs.The expression of Ta PP2C27 gene was related to plant species and sunshine duration in different tissues and organs.It was speculated that the expression of Ta PP2C27 gene was related to the photoperiod,but this correlation needs further test.The results of adversity stress showed that Ta PP2C27 gene was induced to express in drought,low temperature,and ABA stress for a period of time.It was speculated that this gene was involved in the ABA stress-resistance signal pathway.3.The plant overexpression vector of Ta PIF4 was constructed and transformed into light-insensitive wheat variety Liaochun 10 and the light-sensitive wheat variety Ningchun 36 by Agrobacterium-mediated method.Then transgenic seeds T0 generation were havrested when the transgenic wheat was ripe.Further studies on the genetic stability of transformed progeny by Agrobacterium-mediated method are still needed in subsequent experiments.