Identification of CsRNF144 as a key gene regulating di-hydroxy catechins accumulation in Camellia tachangensis through genome-wide association studies

Abstract

Tea is a widely consumed and nutritious beverage, rich in amino acids, caffeine, and catechins, which contribute to its taste and health-promoting properties. While much research has focused on catechins, which are essential for black tea quality, di-hydroxy catechins have received less attention. The genetic mechanisms that regulate the accumulation of these specific still need to be better understood, creating a gap in breeding strategies aimed at enhancing tea quality. This study conducted a genome-wide association study (GWAS) on 329 tea accessions from three species (Camellia tachangensis F. C. Zhang, Camellia sinensis var. sinensis, and Camellia gymnogyna Chang) to address this gap, identifying significant variation in di-hydroxy catechin content. C. tachangensis displayed notably higher di-hydroxy catechin levels, and 44 significant SNPs and 5 candidate genes were identified. Functional analysis, including overexpression in tobacco and antisense oligodeoxynucleotide (AsODN) experiments, showed that CsRNF144 plays a critical role in this process. Overexpression of CsRNF144 led to increased di-hydroxy catechin content, while AsODN interference in C. tachangensis significantly reduced di-hydroxy catechin levels, confirming the gene’s involvement in efficient accumulation. These findings identified a gene involved in the efficient accumulation of di-hydroxy catechins in C. tachangensis and provide a theoretical foundation for future tea breeding programs aimed at enhancing flavor. Additionally, the results emphasize the importance of protecting and developing wild tea accessions, which could serve as valuable genetic resources for improving cultivated varieties.