AP2ERF家族苞片发育相关基因的克隆鉴定及功能研究

AbstractDavidia involucrata is a deciduous tree with wild species only growing in southwest andcentral China.The base of the Davidia involucrata inflorescence has opposite bracts andspecial metamorphosis leaves.Bracts may be special organs formed during long evolutionaryprocess to resist environmental changes or protect breeding organs.Because of its uniqueinflorescence and special genetic status,it has high research value and ornamental value.AP2/ERF transcription factors are widely present in plants.Studies have confirmed thatAP2/ERF transcription factors are closely related to flowering regulation and floral organdevelopment in plants.The main purpose of this study was to obtain transcriptome data ofbracts and leaves at different developmental stages of Davidia involucrata and screen out theAP2/ERF family genes that regulate the development of the bracts of Davidia involucrata.Through gene cloning,expression pattern analysis and functional identification,the regulatorymechanism of these genes in the development of the bracts of Davidia involucrata waspreliminarily explored.It provides clues for the regulation of flowering of Davidiainvolucrata.The main results of this study are summarized as follows:1.According to the transcriptome sequencing results,403 transcription factors in theDavidia involucrata AP2/ERF family were identified.Through domain analysis,expressionpattern analysis and differential cluster analysis,these transcription factors were divided intofive subfamilies,and four genes related to the development of bract were identified bybioinformatics analysis.2.Cloning,sequence analysis and subcellular localization of four target genes DiAP2-1,DiDREB-1,DiRAV-/and DiRAV-2 from three different subfamilies showed that DiAP2-I wasmainly located in the cytoplasm.DiDREB-1,DiRAV-/and DiRAV-2 are mainly located in thenucleus.3.The expression pattern of AP2/ERF gene in Davidia involucrata was analyzed.Theexpression patterns of DiAP2-1,DiDREB-1,DiRAV-I and DiRAV-2 genes were significantlydifferent in leaf and bract stages,and the expression levels of DiRAV-2 were much higher inbract stages than in leaf.Found in different tissue expression pattern analysis,four main geneexpression in floral organ,root and stem hardly express,combined with the plant flowersABCDE model analysis,the gene may belong to A class,because the main class A gene sepalpetal of flower organ development and not participate in the stamen development,shows thatgenes play an important role in the development of the dove tree bracts.4.Phenotypic analysis showed that,except for DiAP2-I transgenic Arabidopsis plants,