Transcriptome analysis the effect of shading on the regulation of oil metabolism in the mesocarp of oil palm (Elaeis guineensis)

Oil palm (Elaeis guineensis) is a highly productive tropical crop cultivated primarily for its oil-rich fruit, which is widely used in food, cosmetics, and biofuel industries. In this paper, total oil was extracted from oil palm mesocarp under both shaded and control conditions at five different stages and analyzed using gas chromatography. The results revealed a significant increase in total oil content during the late stages of mesocarp development under light conditions. Specifically, in the fourth stage, the shaded group exhibited approximately 35 % oil content relative to fresh weight, compared to about 56 % in the control group. Similarly, in the fifth stage, the shaded group showed approximately 63 % oil content relative to fresh weight, while the control group had around 76 %. This suggests that shading treatment had a profound impact on oil accumulation in oil palm mesocarp. Furthermore, significant differences were observed in the relative content of unsaturated fatty acids during the early stages of mesocarp development under light regulation. Analysis of gene expression differences in fatty acid metabolism, sucrose metabolism, carotenoid metabolism, and ethylene biosynthesis based on transcriptome data from the third, fourth, and fifth stages of shaded and control groups revealed notable patterns. Overall, light regulation significantly influenced various metabolic pathways, including total oil, sugars, carotenoids, and ethylene metabolism, impacting fruit development and metabolic product accumulation in mesocarp of oil palm fruit.