Dynamics of sugars, endogenous hormones, and oil content during the development of Camellia oleifera fruit

Abstract

Camellia oleifera Abel (‘Huashuo’) is an important woody oil species with high economic value. Low yield is the main factor restricting the rapid development of the tea-oil industry. The dynamics of sugars, oil, endogenous hormones, and the genes involved in these pathways, as well as the correlation with oil synthesis-related factors in Huashuo, were investigated. The results showed that oil content was positively correlated with sucrose and starch content but was negatively correlated with reducing sugar content. Pyruvate kinase (PK) and fructose-1,6-bisphosphate aldolase (FBA) of the glycolysis pathway could be beneficial for oil biosynthesis. Higher levels of acetyl CoA carboxylase (ACC), stearoyl-ACP desaturase (SAD), and WRINKLED1 (WRI1), as well as lower levels of omega-6 fatty acid desaturase 2 (FAD2) and lipoxygenase 5 (LOX5) could be responsible for the oil production. The higher expression of gibberellin 20 oxidase (GA20ox), lower expression of gibberellic acid insensitive (GAI), and the increase in 9-cis-epoxycarotenoid dioxygenase (NCED) at the mRNA level could contribute to oil accumulation. The results of this study could provide a reference for increasing the yield of plants related to Huashuo.