Objective  Acid invertase (SAI) plays an important role in litchi sugar metabolism. The litchi LcSAI promoter is cloned and analyzed in order to provide a theoretical basis for the research on the function of LcSAI in regulating litchi sugar metabolism.

Method  With the pulp of Feizixiao litchi as test material, according to the litchi genome sequence information, the 1 500 bp promoter sequence upstream of LcSAI gene was cloned. At the same time, the transcription start sites, cis-acting elements and CpG islands in the promoter sequences were predicted and analyzed by bioinformatics tools.

Result  A 1 514 bp LcSAI promoter sequence was cloned. In addition to a large number of promoter core elements such as TATA-box and enhancer element CAAT-box, promoter cis-acting elements also had light-responsive cis-elements, hormone response elements, anaerobic inducible response elements, and MYB binding sites, MYC binding sites and some cis-acting elements of unknown function. There may be three core promoter regions in the LcSAI promoter sequence. TheLcSAI promoter region did not predict CpG islands that met the defined conditions.

Conclusion  The LcSAI gene promoter is related to adversity stress. It is predicted that LcSAI plays an important role in the physiological process of litchi resisting adversity stress.