Identification,characterization And Function Of TaHsf1 Gene In Wheat

Global warming has become an indisputable fact and the frequent extreme weather will damage crop growth and yield irreversibly.High temperature stress as one of the major abiotic stress factors affects crop growth and limits crop yields,thus cultivating high temperature resistant crop is one of the current important crop breeding work we must face.Heat stress transcription factors(Hsfs)are important groups of plant transcription factors,which regulate responses to heat stress in plant through activation of heat shock gene expression.Current researches about plant Hsfs are mainly concentrated on a few plants such as Arabidopsis(Arabidopsis thaliana),rice(Oryza sativa L)and tomato(Solanum lycopersicum).Cloning and function analysis of wheat(Triticum aestivum L)Hsf genes were rarely reported.Research about wheat Hsfs is still at the initial stage,thus,there is still a lot of work required to do about cloning and function analysis of wheat Hsf genes.In this study,the wheat TaHsf1 gene was cloned,expression pattern analysis were widely carried out under abiotic stresses,subcellular localization of TaHsf1 was detected,and its function was analyzed through the transformation of model plant Arabidopsis thaliana.The main results of this study are as follows:(1)TaHsf1 a wheat Hsf gene was cloned from wheat cDNA.The total length of the TaHsf1 gene was 711 bp and the protein contained 236 amino acids.Phylogenetic analysis showed that TaHsf1 belonged to class C Hsfs.Analysis of TaHsf1 protein structure was carried out using the Pfam,SMART,PredictNLS and NetNES online tools,and it was found that TaHsf1 contained a Hsfs typical structures and a complete coiled-coil structure.Multiple sequence alignment revealed that TaHsf1 contained highly conservative functional areas similar to subclass C Hsfs in some other plants.The homology value of TaHsf1 and rice OsHsfC1b reached 77.78%,while the value of TaHsfl and OsHsfC1a/AtHsfC1 only 35.06%and 29.43%respectively.(2)Expression patterns under different stresses of TaHsf1 gene was investigated using real-time quantitative PCR(qRT-PCR)assay.It was found that TaHsf1 gene was induced by high temperature,low temperature,drought,salt stress and ABA(Abscisicacid).1.TaHsf1 gene was induced by high temperature:TaHsf1 gene was induced 1h after exposed to high temperature,and the expression value reached maximum at 2 h;2.TaHsf1 gene was induced by low temperature:TaHsf1 gene was induced 2h after exposed to low temperature,soon the expression value reached maximum at 4 h;3.TaHsf1 gene was induced by drought:TaHsf1 gene was induced 2 h after exposed to drought stress,and the expression value reached maximum at 6 h;4.TaHsf1 gene was induced by salt:the expression value of TaHsf1 gene did not seem to change obviously at the first 2 hours,and 4 h after treated its expression value was gradually on the rise and peaked after 12 h;5.TaHsf1 gene was induced by ABA:at 1h after ABA treatment,TaHsf1 gene showed maximum expression.Probably,TaHsf1 was involved in a variety of abiotic stress responses.(3)The subcellular localization vector 16318hGFP::TaHsf1 was built,and then transferred into wheat mesophyll protoplast mediated by PEG.Using laser confocal microscope was used to detect subcellular localization of the target protein and 16318hGFP.As control,16318hGFP was fluorescent in cytoplasm,nucleus,cell membranes,while the target protein TaHsf1 was only fluorescent in the nucleus.Consequently,TaHsf1 was located in the nucleus.(4)Transgenic Arabidopsis was obtained using transformation mediated by soil agrobacterium(Agrobacterium)containing plant expression vector pBI121::TaHsf1.T3 generations of transgenic Arabidopsis plants or seeds were treated under heat stress and drought stress.It was preliminary showed that the ability resisting to heat and drought stress was improved in transgenic Arabidopsis due to overexpression of TaHsf1 gene.This work will provide the theoretical basis for transgenic breeding using TaHsf1 gene.