The Chromosomal Localization,Gene Expression Profile And Functional Analysis Of Maize Transcription Factor ABP9

Maize transcription factor ABP9 was cloned from maize immature embryos 17 days after pollination which is specially interacting with ABRE2 motif of maize Cat1 gene. Previous research obtain the totally cDNA sequence of ABP9 is 1,510 bp,, and the open reading frame is 1,158 bp. Study comfirmed that ABP9 gene was induced by many abiotic stresses; ABP9 over expression transgenic Arabidopsis can greatly improve plant tolerance to drought, low temperature, high salt and other abiotic stresses. ABP9 can also response to ABA and stomatal closing. In stress, ABP9 transgenic Arabidopsis can improve its photosynthetic capacity, and has a stronger ROS scavenging ability, indicate ABP9 participate in response the plant stress pathway. Nevertheless, the study of ABP9 needs further excavation. The first part was to select single clones from the bacterial artificial chromosome(BAC) library of maize inbred line Qi319 which contain ABP9 gene. Sequencing and alignmen anaylsis was for ABP9 chromosome location; The second part was to construct Pabp9-GUS transgenic maize in order to study the temporal-specific expression of ABP9 in the whole process of growth and development; The third part was to research the phenotype and the ability to resist stress of ABP9 transgenic maize which driven by different promoters. The results are as follows:1、 Application of PCR-based method obtained 19 positive mix pools from BAC library, chosen BAC-103, BAC-159 for further screening. Finally, we found four positive single clone: BAC-103-C3, BAC-103-L5, BAC-159-D1, BAC-159-E1.2 、 Select BAC-103-C3 for full sequencing and alignmen anaylsis, ABP9 gene located on chromosome 3 of maize inbred line Mo17.3、 Gene development expression profiling of ABP9 found it strongly expression in plumule and radicle of 24 hours of germination(G0) and the whole plant of sowing after 6 days(G1),seed pericarp of V18 and R1; seeds of 6, 8 day after pollination, other period or tissues are not expressed or weak expression.4、 Analysis of photosynthetic parameters of Postuba4-ABP9 transgenic maize under drought stress, result showed that photosynthetic capacity and water use efficiency of transgenic lines are better than non transgenic lines. It also showed that the Postuba4-ABP9 transgenic lines could improve the drought tolerance of maize.5、 According to the maize gene chip analysis results, we cloned six moderate expression promoters from the maize inbred line B73, from protoplast transient expression system we sleect two promoters to build a stable expression vector and transform to maize for further analysis.Results of this study laid the foundation to analysis the structure, function, and expression regulation of ABP9, it also helps to the development of molecular marker of the gene, molecular marker assisted and transgenic breeding.