Function Analysis Of Heat Shock Transcription Factor ZmHsf-17 Of Zea Mays

Maize is one of the three grain crops in the world.Maize accounts for a large proportion of grain yield.Not only important food grain is it,but is a valuable animal feed,can also be used as a variety of industrial raw materials.Maize has many advantages,such as,yield high and extensive use,so the production development of maize is very important for the people's livelihood improve and the development of the rural economy.In the production process of maize,temperature,drought,salinity are important external factors.However,in recent years,increasing of the greenhouse effect has led to extreme high temperature,and gives rise to serious adverse effect on maize growth and yield.Temperature has become an important factor in causing the decline of agricultural production and quality.Resilience-related functional genes have important implications for improving plants stress tolerance and foster resilience of New Varieties of Plants.The study found that stress can induce the transcription factor and started downstream resilience functional gene expression,and then improving plant tolerance to stress.HSF(Heat shock transcription factor,Hsf)as a terminal signal of transduction pathway components is the core regulatory factors for heat shock proteins and other heat shock genes,and plays an important role in improve the heat resistance of plants.Currently,despite the heat shock transcription factors made some important results in the model plant Arabidopsis and tomato,but is poorly understood for maize heat shock transcription factor function.Therefore,this study by means of molecular biology,cloned maize heat shock transcription factor ZmHsf-17 by PCR.And use the transgenic technology method to import this gene to rice and analysis its function.The main results obtained are as follows:1.Based on the results of phylogenetic and expression pattern analysis,We screened and cloned the full-length sequence of ZmHsf-17 from maize inbred B73 genome.Sequence analysis showed that full-length of this c DNA was 1125 bp and encoding 375 amino acids,is consistent with the sequence B73 maize genome databases published.Further analyzed7 found that there is a conservative HSE cis-acting elements upstream 636-648 bp of 5 flanking region of ZmHsf-17 genome.2.Bioinformatics results showed that ZmHsf 17 contains ABRE,DRE and LTRE element,ABRE for ABA-responsive element;DRE involved in drought,salt and cold stress;LTRE is the low temperature response element.3.Induced expression patterns analysis showed that Zmhsf-17 was not only induced by heat shock stress,also respond to ABA,drought,salt and cold stress.The tissue expression pattern analysis of ZmHsf-17 indicated that ZmHsf-17 was expressed in roots,stems,leaves,ear,male inflorescence,bract and filaments,and the highest expression level was detectedin leaves.4.Subcellular localization analysis showed Zmhsf-17 protein is a nuclear protein localization.Yeast hybrid assays showed that Zmhsf-17 can activate the expression of the reporter genes,This result is consistent with the characteristics of heat shock transcription factor A2 subfamily.5.ZmHsf-17 overexpressing transgenic plants have no significantly differences in the morphology compared with control plants.,However,ZmHsf-17 transgenic rice showed a strong tolerance by heat shock stress.Results of ZmHsf-17 ABA sensitivity experiments showed that the sensitivity of transgenic plants to exogenous ABA is significantly intensity compared with the control plants.Maize under hydrogen peroxide oxidative stress will induces ZmHsf 17-expression.In summary,we obtained a candidate gene ZmHsf-17 based on the analysis results of genetic structure,evolution and expression patterns induced by heat shock and other stress resistance,cloned and analyzed the molecular characterization of the gene.Overexpressed the gene in rice significantly increased transgenic plants tolerant to high temperature,it provides excellent genetice resources for the improvement of resistance crops Transgenic plants increased sensitivity to ABA and ZmHsf-17 gene expression upregulation under the ABA stress,indicating that the gene expression is mainly regulated by ABA signaling pathway to regulation the expression of functions genes.