RESUMO
<b>Background and Objective:</b> Sunflower is one of the important commodities in agriculture. The oil content in sunflower seeds has been widely used as cooking oil, but in Indonesia, the utilization of this oil is still relatively low. In addition, sunflowers also contain vitamin E which is useful as an antioxidant, so it can be used to reduce the risk of cardiovascular disease. This study aims to determine gene expression at the RNA level towards vitamin E biosynthesis using different fertilization treatments. <b>Materials and Methods:</b> Sunflowers that had been given different fertilizers were taken in three flowering phases, R3, R5 and R8. Flower samples were isolated until RNA was obtained. The isolation results were tested using real-time PCR to determine the relative gene expression of the <i>VTE1</i> and <i>VTE3</i> genes. After the sunflower seeds were fully ripe, vitamin E content was tested in each treatment and the results were compared with the relative gene expression obtained. <b>Results:</b> The results obtained were fluctuating, but in general, the relative gene expression obtained in the <i>VTE1</i> gene increased in the R3 phase and then decreased in the R5 and R8 phases. Whereas, in the <i>VTE3</i> gene, the relative gene expression obtained experienced an increase in the R3 and R5 phases and then decreased in the R8 phase. The highest vitamin E content was obtained by sample P3 (4218 µg mL<sup>1</sup>) and the lowest was obtained by sample P2 (1798 µg mL<sup>1</sup>). <b>Conclusion:</b> A balanced ratio of 92:46:30 kg ha<sup>1</sup> of major nutrient fertilizer involving N, P and K could increase vitamin E content in sunflowers. Such a combination exhibited stable expression of the <i>VTE1</i> and <i>VTE3</i> genes in all phases of flowering.
