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

Lanxiang Wang,Andy C.W Lui,Guoquan Liu,Ian D Godwin,Clive Lo,Pui Ying Lam

doi:10.1111/pbi.13397

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.

Highlights

Acid-hydrolysed extracts of different tissues were prepared for LC-MS/MS analysis
The flavonols kaempferol, quercetin and isorhamnetin were detected in all spikelet extracts analysed, while isorhamnetin accumulated in slightly higher amount in OE3 than Tx430 control (Figure 1d)
Kaempferol, isorhamnetin and syringetin were identified in both transgenic lines, but none of these flavonols were found in Tx430 (Figure 1e)

Summary

Introduction

The flavonols kaempferol, quercetin and isorhamnetin were detected in all spikelet extracts analysed, while isorhamnetin accumulated in slightly higher amount in OE3 than Tx430 control (Figure 1d). Overexpressing SbF3H1 did not have a substantial impact on flavonol production in tissues with endogenous F3H activities. Kaempferol, isorhamnetin and syringetin were identified in both transgenic lines, but none of these flavonols were found in Tx430 (Figure 1e).

Results

Conclusion