Identification Of Transcription Factors Expression Of CesA1 And CesA7 In Maize Development By GA

Maize grain mainly includes seed skin,endosperm and embryo three major parts,the main components in the grain are protein,fat,water,vitamins,mineral elements and other substances,of which cellulose accounts for about 6%-8%of the total weight of seeds,with the protection of seeds from external forces mechanical damage and prevent pest invasion of the role,It plays an important protective role in the growth and development of maize and the storage process.It is of great significance to study the grain development of maize for the high yield and stable yield of maize and to ensure the food security of the country.At present,there are many studies on the signal transduction pathway mediated by Gibberellin（gibberellin,GA）,which mainly focus on regulating seed germination,flower development and plant tissue growth,but it is rare to report how GAregulates maize grain development.In this group,50mM GA₃ was used to treat maize plants with similar growth in the field,and the content of cellulose in grain was determined after receiving the species,and the results further proved the effect of GA on grain development in practical production in the field.The grain of 10DAP after Mo17 pollination of maize inbred line was treated by GA,and the transcription group was sequenced by RNA-Seq high-throughput sequencing technique.The sequencing data of transcription group were analyzed,21 transcription factor families and 52transcription factors were screened,and 6 transcription factors were selected as candidate genes by bioinformatics to predict the genes with significant differential expression,and some basic experimental screening was used to finalize bZIP53,ZmMADS18 and NAC38 these three transcription factors were used as transcription factors in this experiment.Through the existing homologous pairs of grain development related genes in Arabidopsis and rice,which are analyzed in sequencing data,the related genes in maize grain development regulated by GA are preliminarily screened,and 13 important functional genes are obtained through the comprehensive consideration of expression and so on.In the 13 functional genes selected,it was found that GA had 4 genes related to cellulose synthase,and it was speculated that GA might regulate the development of grain by promoting the expression of cellulose synthase gene in maize grain.Maize contains 9 cellulose synthase,cloning these 9 cellulose synthase,through some experimental screening to finalize the cloning of CesA1 and CesA7 promoter as the study object.In this experiment,the expression of the promoter factor bZIP53,ZmMADS18 and NAC38 to CesA1 and CesA7,which may regulate the process of grain development,was studied emphatically,and the expression pattern,its own characteristics and the influence with the promoter of cellulose synthase were determined.The results of the specific study are as follows:1.After GA treatment,grain bulk weight,grain length and cellulose content increased,the content of cellulose in the outer tissue of grain was significantly higher than that of other tissues,and the endosperm structure changed obviously.2.bZIP53,ZmMADS18 and NAC38 genes were expressed in maize grain.The highest expression of bZIP53 in 7DAP was measured in the grain after GA treatment and pollination,the highest expression of ZmMADS18 in 7DAP and the highest in 10DAP NAC38.At the same time,we positioned bZIP53 in the nucleus of the protoplast cells of maize leaves,and the ZmMADS18 and NAC38 were located in the protoplast nuclei and cell membranes of maize leaves.3.Molecular biology experiments have shown that transcription factor bZIP53 can simultaneously improve the expression of CesA1 and CesA7 promoter,can be directly combined with CesA1 and CesA7 promoter,but it does not have yeast activation,so it is speculated that there may be other trans effects involved in its regulation,and further research is needed.ZmMADS18 transcription factor can obviously improve the expression of CesA1promoter,can directly combine with CesA1 promoter to regulate the expression of modified gene,and has activation effect.NAC38 transcription factors promote the expression of CesA7promoter,but NAC38 may be toxic to yeast and can not verify the activation of transcription factors and the binding effect with promoter.