Correlation between squalene synthase promoter and WRKY transcription factor in Camellia oleifera

ABSTRACT

Tea oil obtained fromCamellia oleifera is a high-quality vegetable oil rich in squalene, a triterpenoid bioactive substance with several demonstrated health benefits. WRKY transcription factors in C. oleifera play essential roles in a wide range of physiological processes. To further develop C. oleifera as a functional material with genetic improvement, we constructed a tea oil seed transcriptome database and screened out the C.oleifera WRKY genes (CoWRKY) to determine their relation with squalene anabolism. Forty-one CoWRKY transcription factors were obtained, including five showing a potential association with squalene metabolism and  regulating the expression of the squalene synthase gene (CoSQS). Through bioinformatics analysis of the CoSQS promoter, it was predicted that W-box components that may bind to CoWRKY were present at the – 293 bp position. Real-time polymerase chain reaction showed a significant positive correlation between the expression levels of the CoWRKY1 and CoSQS genes, further indicating their interaction, which was confirmed via a yeast one-hybrid assay. Overall, these results suggest that the CoWRKY1 transcription factor may bind to the W-box cis-acting element of the CoSQS promoter to positively regulate the synthesis of squalene in C. oleifera, offering new strategies for engineering strains with production of oil highly enriched in squalene.

KEYWORDS:

• Camellia oleifera
• WRKY transcription factor
• bioinformatics
• cis-acting element
• squalene
• squalene synthase gene promoter

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This project supported by the Natural Science Foundation of Hunan Province, China (Grant No. 2019JJ50986).