COMPARATIVE TRANSCRIPTOMIC ANALYSES OF HIGH AND LOW OLEIC ACID CONTENT SUNFLOWER (HELIANTHUS ANNUUS L.) SEED DEVELOPMENT

Helianthus annuus L. seeds possess high nutritional value and more stable oleic acid oil. Initial analysis of sunflower seed for oleic acid content during seed development revealed rapid oleic acid accumulation by 17 days after flowering (DAF), with high oleic acid levels persisting until after 27 DAF. Subsequent transcriptome sequencing analysis of high ('L-1-OL-1') and low ('86-1') oleic acid oil-producing sunflower cultivars enabled gene expression profile comparisons. Further analysis on differentially expressed genes (DEGs) in seed from different group at 17 and 27 days revealed 5971 (2751 up, 3220 down), 4906 (2518 up, 2388 down), 12761 (5807 up, 6954 down), and 9883 (3803 up, 6080 down) DEGs for D8617d vs D8627d, D8617d vs L17d, D8627d vs L27d, and L17d vs L27d, respectively. DEGs annotation detected the key fatty acid biosynthesis genes and transcription factors with potential roles in lipid metabolism. Furthermore, quantitative real time PCR (RT-PCR) results of 12 DEGs involved in fatty acid metabolism were positively correlated with their expression patterns using RNA-Seq implying a good reliability of results produced by this method. The results in this research may pave theoretical basis for researching molecular mechanisms of sunflower lipid metabolism.