Histone Acetylation Of Wheat Albinism Line Under Low Temperature

As a common post-translational modification and epigenetic modification,Histone acetylation can change chromatin configuration,then result in the activation or silencing of transcription.Histone acetylation is reversibly regulated by histone acetyltransferases(HATs)and histone deacetylases(HDACs).Changes of histone acetylation and abnormal expression levels of HDACs are involved in responses to abiotic stresses in plants.In the field,wheat Albinism line have both green plants and white plants in the process of albino,which may affected by epigenetic modification.The previous exprements revealed that there were big differences in expression levels of some HDACs and Sin3 complex genes in wheat Albinism line and Aibian No.1.We assume that histone acetylation of leaves is quite different between wheat Albinism line and Aibian No.1 under low temperature.Histone acetylation of H3K9、H3K14、H4S1/K5/K8/K12 were analyzed in wheat Albinism line and Aibian No.1 under low temperature,and expression levels of six HDACs genes were studied under low temperature.Trichostatin A was uesd to screen transcription factors regulated by HDACs.Then Sin3/HDAC complex was analyzed in wheat.The main conclusions in this paper are as follows:1.The antibody of H3K9 Ac,H3K14Ac and H4S1/K5/K8/K12 Ac were used to analysis histone acetylation in two kinds of wheats in western blot experiments.The results showed that histone acetylation levels of H3K9 Ac and H4S1/K5/K8/K12 Ac were significantly declined in Albinism line compared with Aibian No.1 under low temperature.Both histone acetylation modification including H3K14 Ac in Albinism line were higher than that in Aibian No.1 in early phages of low temperature treatment(2 days).2.Genes expression levels of TaHDA6、TaHDA8、TaHDA9、TaHDA14、TaHDA15、TaHDA19 were analyzed under low temperature in two kinds of wheats.It indicated that expression of TaHDA14 was down-regulated with the treatment time of lower temperature prolonged.But expression level of Albinism line was always higher than Aibian No.1.Expression patterns of TaHDA6,TaHDA8,TaHDA9,TaHDA15,TaHDA19 were different.They increased first in early phages of low temperature treatment,then gradually declined.Expression levels of all six genes in Albinism line were higher than that in Aibian No.1.It can explain why histone acetylation of Albinism line was lower under low temperature.3.The Sin3 gene was successful y amplified in wheat.Amino acid sequence alignment of Sin3 protein in wheat,Arabidopsis thaliana,rice,maize and Brachypodium distachyon have extensive similarity.It suggest that structures and functions of Sin3 in plants are very conservative.The interaction of Sin3 and HDA19 in wheat was verified through the yeast twohybrid test,and the interaction segment in Sin3 is PAH domain.Pull down assay can further verify this conclusion.4.Expression patterns of Sin3 and SAP18,the essential components of Sin3/HDAC complex,were analyzed under low temperature in two kinds of wheats.It reveals that expression levels of Sin3 and SAP18 in Albinism line were higher than that in Aibian No.1 in early phages of low temperature treatment.Expression patterns of Sin3 and HDA19 were very similar in Albinism line.It indicated that Sin3/HDA19 complex may be the major way that HDA19 functions.5.After treated with 400 nmol/L trichostatin A under low temperature,expression of DREB4 and DREB6 were significantly restrained in Albinism line.It showed that the expression of DREB4 and DREB6 were induced by histone deacetylases.The expression patterns of DREB4 and DREB6 were different in two kinds of wheats under low temperature,DREB4 had higher expression level in Albinism line,While DREB6 had higher expression level in Aibian No.1.6.The method system of chromatin immunoprecipitation(Ch IP)used for histone acetylation analysis was preliminarily established.In a word,the expression levels of HDACs in Albinism line were higher than that in Aibian No.1 under low temperature.It led to the decrease of histone acetylation in Albinism line compared with Aibian No.1.The interaction of Sin3 and HDA19 in wheat was verified through the yeast two-hybrid test and pull down assay.Furthermore,the expression of essential components of Sin3/HDAC complex in Albinism line were higher than that in Aibian No.1 in early phages of low temperature treatment.