Abstract: The aim of this study was to investigate the function of Jatropha curcas JcBELL1（BEL1-LIKE HOMEODOMAIN 1） gene in regulating plant leaf senescence.In this study,bioinformatics analysis of JcBELL1 gene was carried out,JcBELL1 gene overexpression vector was constructed,and wild-type Arabidopsis thaliana was transformed by Agrobacterium-mediated flower dipping method;furthermore,wild-type Arabidopsis thaliana Col-0、mutant bell1 and overexpressed JcBELL1 gene plants were used as materials to analyze leaf senescence related physiological indicators and the expression of senescence related genes.The results showed that Jatropha curcas JcBELL1 protein contained 690 amino acids.Amino acid sequences comparison and phylogenetic tree analysis showed that,compared with Arabidopsis thaliana AtBELL1,Jatropha curcas JcBELL1 is more closely related to Ricinus communis RcBELL1.Real time quantitative PCR was used to analyze the expression specificity of JcBELL1 gene in different tissues of Jatropha curcas.The results showed that JcBELL1 gene was highly expressed in old leaves,female flowers and male flowers of Jatropha curcas.Further analysis of the changes of JcBELL1 gene in each developmental stage of leaves showed that JcBELL1 gene expression increased with the increase of leaf age.Promoter analysis revealed that there were 17 elements with different functions on the promoter of JcBELL1,involving light response,hormone regulation and meristem expression.Overexpressed JcBELL1 gene plants can delay rosette leaves senescence.Compared with Col-0 and bell1,JcBELL1 had higher rosette number,fresh weight,dry weight and chlorophyll content.The expressions of aging related genes AtSAG13,AtWRKY75 and AtGLN1 in overexpressed JcBELL1 gene plants were significantly lower than those of Col-0 and bell1.These results suggest that the heterologous Jatropha curcas JcBELL1 gene regulates leaf senescence process,and delays leaf senescence in Arabidopsis thaliana.