The Functional Analysis Of ANE1,An Enhancer Of ANGUSTIFOLIA In Arabidopsis

Plant organ growth and final shape relies on the cell proliferation and cell expansion.Special cell morphology and organ function are also closely related.ANGUSTIFOLIA(AN)is a plant homolog of CtBP/BARS(C-terminal-binding proteins)in animal.The function deletion of AN leads to narrow cotyledons,rosette leaves and petals,and less-branched trichomes.However,besides the knowledge that AN regulates cell and tissue morphogenesis by modulating CMT(cortical microtubules),precious few researches demonstrated AN function at molecular level.In this study,we screened an enhancer mutation anel-1/an-2 after chemical mutagenesis of an-2(AN deletion mutation)by EMS.Then the single point mutation anel-1 was isolated.After the preliminary phenotype analyse,anel-1 showed narrower cotyledons while anel-1/an-2 significantly enhanced the phenotype of an-2 in cotyledons(much slender).The further analyse on the cell level revealed that the pavement cells of an-2,anel-1 displayed less lobes,the lobes number of anel-1/an-2 almose disappeared.Simultaneously,anel-1 and anel-1/an-2 showed narrower petal shape.Interesting,the transverse microtubules in their abaxial cells increased significantly.Luckly,the definite gene,TPR1(ANE1),was cloned by combing mapping cloning,high-throughput sequencing and allelic hybridization.The transient expression in Arabidopsis seedlings showed that TPR1 obviously co-localized with CMT,indicating that TPR1 may directly participate in the regulation of microtubules.The results suggested that an-2 and anel-1/an-2 showed significantly changes in leaves and petals phenotype,suggesting that both AN and TPR1 are involved in the process of growth and development in Arabidopsis thaliana,TPR1 may control the polar growth of epidermal cell,determine the final shape by modulating the CMT orientation.This investigation provides a theoretical basis for further elucidating the function of ANGUSTIFOLIA in plant cell and organ morphogenesis.