Transgenic expression of flavanone 3-hydroxylase redirects flavonoid biosynthesis and alleviates anthracnose susceptibility in sorghum

Abstract

Flavonoids are ubiquitous in terrestrial plants with important physiological functions. The in planta flavonoid profile depends on the activities of different biosynthesis enzymes (Figure 1a). Flavanone 3‐hydroxylase (F3H) is a key enzyme channeling carbon flow towards the production of 3‐hydroxylated flavonoids, including flavonols and anthocyanidins. In Poaceae, F3H‐encoding genes are generally inactive in vegetative tissues which accumulate flavone derivatives as the predominant flavonoid metabolites. Meanwhile, sorghum produces 3‐deoxyanthocyanidins and flavones as phytoalexins for defense against pathogens such as Colletotrichum sublineola, the causal agent of anthracnose.