Over-expression Of CiHARBI1 From Caragana Intermedia Affected Cotyledon Morphogenesis Of The Transgenic Arabidopsis

The control of organ shape is an essential developmental process.So far,the regulation mechanism of plant organ morphogenesis has not been elucidated.Leaf is the key vegetative organ of plant.The change of its morphology affects the response of plant to abiotic stress signals largely.It is of significance in deepening the understanding of plant development and stress resistance mechanism with further study on the regulation mechanism of leaf formation and development.HARBI1?Harbinger Transposase Derived 1?belongs to the DDE_Tnp₄ family,and there were few studies on the function of HARBI1 in plants.In this paper,the CiHARBI1,a multi stress response gene,was isolated from the transcriptome of drought-treated Caragana intermedia Kuang et H.C.Fu constructed in our laboratory,and the role of CiHARBI1 in growth and development in plant was studied in Arabidopsis thaliana.The results are as follows:1.A multi-stress related gene,CiHARBI1,which belongs to DDE_Tnp₄ family,was isolated from C.intermedia.CiHARBI1 was induced by drought and NaCl stresses rapidly.2.The axial position of the cotyledons was sunken in high and medium level of the CiHARBI1 over-expression lines.Among the high level over-expression lines,some cotyledons even could not open,and showed typical cytokinin responses.The morphology of rosette leaves had been changed too and the bolting time had been delayed in CiHARBI1 over-expression lines compared with wild type.CiHARBI1 regulates the cell morphology and the crosslinking degree of pavement cells of cotyledon,and the effect of CiHARBI1 seemed to have a dose effect.3.CiHARBI1-GFP localized in the nuclei.Related cis-elements involved in many abiotic stress and plant hormone responses were predicted from the promoter of CiHARBI1.The expression of the CiHARBI1 was spatio-temporal specifically expressed in tissues with active cell division.4.Content of various cytokinins was significantly higher than that in the wild type,while auxin content was significantly lower than that in the wild type in the 7-day-old high level of CiHARBI1 over-expression lines.