Diacylglycerol Acyltransferase1 Promotes Triacylglycerol Biosynthesis in Oil Tea (Camellia oleifera) Seeds through Transcriptional Activation by WRINKLED1

Authors: ZHAO, GUANG - Central South University; LIAO, CHANCAN - Central South University Of Forestry And Technology; LONG, HONGXU - Central South University; Cao, Heping; ZHANG, LIN - Central South University Of Forestry And Technology

Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/4/2025
Publication Date: 6/12/2025
Citation: Zhao, G., Liao, C., Long, H., Cao, H., Zhang, L., 2025. Diacylglycerol Acyltransferase1 Promotes Triacylglycerol Biosynthesis in Oil Tea (Camellia oleifera) Seeds through Transcriptional Activation by WRINKLED1. Journal of Agricultural and Food Chemistry. https://doi.org/10.1021/acs.jafc.5c02120.
DOI: https://doi.org/10.1021/acs.jafc.5c02120

Interpretive Summary: The seed oil from oil tea (Camellia oleifera) is a high quality edible oil. However, the regulatory mechanism of seed oil accumulation remains largely unknown in this plant. We identified three diacylglycerol acyltransferase genes (CoDGAT1, CoDGAT2 and CoDGAT3) and showed that CoDGAT1 was the major one contributing to seed TAG biosynthesis. Our study indicated that CoWRI1enhanced seed oil content by transcriptional activating CoDGAT1; phytohormones and environment signals may regulate TAG accumulation through CoWRI1-CoDGAT1 pathway. This study provided theoretical guidance for breeding of high-yield oil tea varieties via biotechnological manipulation.

Technical Abstract: Camellia oil, a nutritionally rich edible oil derived from Camellia oleifera seeds, is predominantly stored as triacylglycerol (TAG) during fruit maturation. However, a limited understanding of the genetic and regulatory mechanisms governing Camellia oil accumulation has hindered efforts to optimize its yield. In this study, three C. diacylglycerol acyltransferase (CoDGAT) genes were identified and characterized, wherein CoDGAT1 emerged as the primary contributor to seed TAG biosynthesis, functioning within the endoplasmic reticulum and increasing seed oil content by 64.4% in transgenic plant. Through weighted gene coexpression network analysis, we identified WRINKLED1 (CoWRI1) as a candidate transcriptional regulator of CoDGAT1. Both genes exhibited significant upregulation during seed maturation. Mechanistically, CoWRI1 activated CoDGAT1 by directly binding to AW-box motifs in its promoter, thereby promoting TAG accumulation. Additionally, CoWRI1 expression was suppressed by salicylic acid, methyl jasmonate, and darkness, suggesting that phytohormones and environmental signals modulate TAG accumulation through the WRI1-DGAT1 pathway. These findings provide an important basis for improving Camellia oil production through biotechnological manipulation of DGAT1 and WRI1 genes.