Abstract

Hydrolyzable tannins (HTs), predominant polyphenols in oaks, are widely used in grape wine aging, feed additives, and human healthcare. However, the limited availability of a high-quality reference genome of oaks greatly hampered the recognition of the mechanism of HT biosynthesis. Here, high-quality reference genomes of three Asian oak species (Quercus variabilis, Quercus aliena, and Quercus dentata) that have different HT contents were generated. Multi-omics studies were carried out to identify key genes regulating HT biosynthesis. In vitro enzyme activity assay was also conducted. Dual-luciferase and yeast one-hybrid assays were used to reveal the transcriptional regulation. Our results revealed that beta-glucogallin was a biochemical marker for HT production in the cupules of the three Asian oaks. UGT84A13 was confirmed as the key enzyme for beta-glucogallin biosynthesis. The differential expression of UGT84A13, rather than enzyme activity, was the main reason for different beta-glucogallin and HT accumulation. Notably, sequence variations in UGT84A13 promoters led to different trans-activating activities of WRKY32/59, explaining the different expression patterns of UGT84A13 among the three species. Our findings provide three high-quality new reference genomes for oak trees and give new insights into different transcriptional regulation for understanding beta-glucogallin and HT biosynthesis in closely related oak species.

Keywords

hydrolyzable tannin; oak; whole-genome sequencing; beta-glucogallin

Published in

New Phytologist
2024,
Publisher: WILEY

SLU Authors

• Bhalerao, Rishikesh P.

  • Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Genetics
Botany


Publication identifier

DOI: https://doi.org/10.1111/nph.19711

Permanent link to this page (URI)

https://res.slu.se/id/publ/129272