Abstract:Abstract The fatty acyl-acyl carrier protein thioesterase (FATA) is a key enzyme in the accumulation of fatty acids, which directly regulates the content and composition of fatty acids. The function of the acyl-ACP thioesterase A gene (GenBank accession number: EU267122.2) in Jatropha curcas has not been reported before. In this study, the JcFATA gene RNAi expression vector had been constructed and down-regulation of JcFATA gene expression was accomplished, the positive fragment FATA1 (439 bp) of JcFATA gene was cloned from Jatropha curcas leaf cDNA , which was then inserted into pYL RNAi.2-35S contained intron to construct the intermediate vector pYLRNAi.2-35S-FATA1; the reverse fragment FATA2 (439 bp) was amplified by PCR used the intermediate vector as a template, and then inserted into the intermediate vector to construct the JcFATA gene RNAi expression vector pYLRNAi.2-35S-FATA1-FATA2; it was transformed into Agrobacterium tumefaciens EHA105 competent cells by electroporation, and then transformed into Arabidopsis thaliana by inflorescence infection method. Finally, the transformation was confirmed by PCR and Southern blot. In addition, preliminary phenotypic observation, expression analysis and determination of fatty acid content of transgenic Arabidopsis plants was carried out in this study, the results indicated that the growth and development of transgenic plants might be inhibited by RNAi expression of JcFATA gene. The results of this study can provide a theoretical basis for further discussion of the function of JcFATA gene and its application in the genetic improvement of Jatropha curcas.