Work

The WRKY transcription factor IbWRKY24 regulates flavonoid biosynthesis in sweetpotato ( Ipomoea batatas [L.] Lam.) blades

Year: 2026

Type: article

Abstract: Sweetpotato (Ipomoea batatas [L.] Lam.) vines exhibit strong regenerative capacity, and their blades are rich in flavonoids, making them a promising target for nutritional biofortification. Here, we quantitatively assessed flavonoid contents and antioxidant capacities in blades from 90 genetically diverse sweetpotato genotypes. Integrated metabolomic and transcriptomic analyses identified IbWRKY24 as a key transcriptional regulator of flavonoid biosynthesis in sweetpotato blades. Overexpression of IbWRKY24 in stable transgenic sweetpotato lines significantly increased blade flavonoid accumulation (1.22–2.34-fold) and antioxidant activity (1.29–2.16-fold), whereas gene silencing caused marked reductions in both traits. Mechanistically, yeast one-hybrid, dual-luciferase, and electrophoretic mobility shift assays demonstrated that IbWRKY24 directly binds specific W-box elements in the promoters of core flavonoid biosynthetic genes, including IbCHS, IbCHI, and IbFLS, thereby activating their transcription. Moreover, developmental profiling revealed a strong concordance between IbWRKY24 transcript abundance and flavonoid accumulation in blades (r = 0.806，P < 0.0001). Together, these results establish IbWRKY24 as a positive regulator of flavonoid biosynthesis and provide insights into transcriptional control of specialized metabolism in sweetpotato. This work offers a molecular target for flavonoid biofortification and high-value utilization of sweetpotato blade resources.

Source: Horticulture Research

DOI: 10.1093/hr/uhag216