Overexpression Of AtHARBI1-1 In Arabidopsis Thaliana Affects Growth And Development Of Cotyledon And Root

The growth and development of plants is regulated by many cues,the morphological formation of organs is very important to the growth and development of plants,leaves are crucial to the production of plant biomass,and the changes of their morphological structure will affect the response of plants to the external stimuli.As an organ for plants to absorb nutrients,the change of root morphological structure directly affects the growth and development of plants as well.The study on the molecular mechanism of regulating the growth and development of plant leaves and roots is of great significance to improve our understanding to the development process and stress resistance mechanism of the whole plant.Harbinger Transposase Derivedl?HARBIl?protein belongs to the DDE_Tnp₄ protein family.At present,except for the study on CiHARBI1 of Caragana intermedia carried out by Liu Jianzheng,the function of HARBI1 in plants has not been reported.In this paper,Arabidopsis thaliana was used as the experimental material to clone and uncover the function of AtHARBI1-1,which shares 70%homology with the multi-stress response gene CiHARBI1.The main results are as follows:1.A DDE_Tnp₄ family gene AtHARBI1-1 was cloned from A.thaliana.The expression of AtHARBI1-1 was rapidly induced by cold stress.2.After homologous overexpression of AtHARBI1-1 in A.thaliana,obvious depression was observed in the apical axis of cotyledons of the transgenic plants,in which the cotyledons curled downward and the hypocotyl dilated;the morphology of rosette leaves was abnormal and the bolting time was later than that of wild type;there was no significant difference between the Atharbi1-1 mutant and wild type,which may be due to the functional redundancy of homologous genes.3.The growth of AtHARBI1-1 or CiHARBI1 overexpression lines was delayed and the root length was significantly shorter than that of wild type plants,and the root hairs of the overexpression lines increased significantly.There was no significant difference between the Atharbil-1 mutant and wild type plants.4.The content of auxins in 7-day seedlings of overexpressed strains was significantly lower than that of wild type,and the content of cytokinins was significantly higher than that of wild type.The above results indicated that,as CiHARBI1,AtHARBI1-1 might affect the content of IAAs and cytokinins of the transgenic Arabidopsis via a currently unknown pathway,and resulted in abnormal cotyledon,leaf and root development in transgenic lines.