Transcriptome Sequencing And Identification And Analysis Of Key Regulatory Genes In Response To Heat Stress In Maize

Heat shock factors(HSF),heat shock proteins(HSP),catalase(CAT)and Ascorbate peroxidase(APX)play a critical role inthe molecular mechanismssuch as plant development and defense against abiotic stress(heat stress,etc.).As an important food crop,Zea mays is vulnerable to adverse environment,such as heat stress and waterlogging,which leads to a decline in yield and quality.To date,Only a few studies on HSP,HSF,APX and CAT gene families are under h heat stress in maize.Therefore,by studying their molecular biology,revealing their biological functions in plant stress resistance process will have important theoretical significance and application value for improving corn yield and quality.This study used the newly sequenced maize genome database to perform genome-wide identification and analysis of maize HSP,HSF,APX and CAT gene family members by bioinformatics methods;The gene expression of Maize B73 strain under heat stress was analyzed by transcriptome sequencing;The expression of maize HSP,HSF,APX and CAT gene families under heat stress was studied by real-time fluorescence quantitative technique.All of these can help to clarify the functions of corn HSP,HSF,APX and CAT and lay a foundation for the molecular mechanism in the process of resisting heat stress.The main experimental results obtained in this study are as follows:1.25 HSF,35 HSPs(including 22 HSP70,2 HSP40,2 HSP90 and 9 s HSP),8 APX and 5 CAT were identified from the maize B73 genome,and identify its physical and chemical properties;The evolutionary phylogenetic relationship was determined by phylogenetic analysis of HSP,HSF,APX and CAT genes in maize,Arabidopsis and rice;The exon-intron structure analysis showed that the number of introns and exons contained in each gene family member is very different,and the length of introns is not the same.These reasons may cause Gene functional diversity;The protein motifs analysis of the maize HSF and HSP family genes indicated that the structure of different proteins showed significant differences in conserved motifs,which provided a basis for their functional differentiation.The expression profiles of maize HSF and HSP family genes in different tissues indicate that gene expression is tissue specific.2.The transcriptome sequencing analysis of the control and experimental(high temperature)materials was performed by RNA-Seq technique,the results showed that 1857 differentially expressed genes(DEGs,1029 up-regulated and 828down-regulated)were identified from 35209446 and 35205472 Clean data,respectively.KEGG pathway enrichment analysis for DEGs indicated that protein processing in endoplasmic reticulum pathways play a central role in maize response to heat stress.In addition,in the present study,167 putative TFs were identified,which belong to various TF families(e.g.,HSF,MYB,AP2-EREBP,b-ZIP,b HLH,NAC and WRKY),and may be associated with heat stress response of maize.The results showed that many genes were differentially expressed in response to heat stress in maize.3.The q RT-PCR technique was used to further verify the expression of maize HSP,HSF,APX and CAT gene family members at high temperature.The results showed that heat stress treatment could induce the up-regulation of most members of these gene families,but some genes were down-regulated,indicating that these genes may play different roles in the response of maize seedlings to heat stress.In addition,the expression levels of these genes in different tissues and organs are different,indicating that their regulation may be tissue-specific.