Identification and expression analysis of some genes involved in flavonoids biosynthesis at different tuber development stages of potato

The high nutritional value has made potato the fourth most important food source after wheat, rice and corn worldwide. In this study, in order to identify and investigate the expression pattern of the most significant genes involved in the synthesis of flavonoids at different potato tuber developmental stages, the RNA sequencing data was obtained from three different potato tuber development stages, namely; initiation of stolon formation, stolon swallowing and initiation of tuber formation. In order to validate the expression of identified genes involved in the biosynthesis of flavonoids in potato tuber (62 genes), the expression of significant genes were evaluated by using qRT-PCR method. The results of this study showed that at the stolon swallowing stage, 10 and 11 genes had a significant increase and decrease in expression, respectively. Comparing the stolon swallowing stage with initiation of stolon formation, 7 and 20 genes showed a significant increase and decrease in expression. At the initiation of tuber formation, it was found that 14 genes had a significant decrease in expression. In total, 4 key genes CYP98A3, ACT, SAT and BEAT were identified with significant changes among developmental stages. The amount of flavonoid in the three developmental stages was also significantly increased with the transition of developmental stages. The average of flavonoid content was 1.9, 7.2 and 24.8 mg/gFW for tree developmental stages, respectively. Since CYP98A3, ACT, SAT and BEAT are key genes involved in the biosynthesis of secondary metabolites in the potato tuber, they can be considered as possible candidate genes for alteration of flavonoids content in potato.