Scientists identify the enzymes behind health-promoting pigment modification in blueberries
image: Estimates of broad sense heritability for raw concentrations of ACN and CGA, and percentage of arabinoside ACN (Arab-P), galactoside ACN (Galc_P), glucoside ACN (Gluc_P) and acylated ACN (Acyl_P) relative to the total ACN (TotalACN) content in 153 blueberry accessions over three years.
Credit: Horticulture Research
Anthocyanins, the pigments that give blueberries their vivid coloration, are also recognized for their potential health benefits. However, their biological effectiveness depends largely on chemical modifications such as acylation, which can increase molecular stability and human absorption. This study performed a genome-wide investigation to pinpoint genetic loci that regulate anthocyanin acylation in blueberries and identified two BAHD-family acyltransferase genes, VcBAHD-AT1 and VcBAHD-AT4, as central regulators of the acylation process. Functional validation using virus-induced gene silencing confirmed that suppressing either gene eliminates the production of acylated anthocyanins. These insights provide a valuable foundation for breeding blueberries with improved nutritional properties and enhanced pigment stability.
Blueberries are widely regarded as a functional food due to their high concentrations of anthocyanins and chlorogenic acid. Yet not all anthocyanins behave identically; their bioavailability, color retention, and metabolic fate depend on how the molecules are structurally decorated. In particular, acylated anthocyanins are known to be more stable and may be more efficiently absorbed. However, the genetic mechanisms controlling this acylation remain poorly understood, complicating targeted breeding efforts. Based on these challenges, there is a critical need to identify the genes that regulate anthocyanin acylation and to clarify their biological roles.
Researchers from North Carolina State University and collaborating institutes reported new findings (DOI: 10.1093/hr/uhaf041) on May 1, 2025, in Horticulture Research. Using a genome-wide association study combined with functional gene-silencing experiments in fruit tissues, the team identified two acyltransferase genes, VcBAHD-AT1 and VcBAHD-AT4, that control the acylation of anthocyanins in blueberry. These findings provide a molecular framework for improving the stability and health-related properties of blueberry pigments.
The study analyzed metabolic and genomic variation across 153 blueberry accessions to identify loci linked to anthocyanin composition. A strong and stable quantitative trait locus associated with anthocyanin acylation was located on chromosome 2. Within this region, five BAHD-family acyltransferase candidates were examined through phylogenetic and transcriptomic comparison. Two genes—VcBAHD-AT1 and VcBAHD-AT4—were specifically expressed in fruit containing high levels of acylated anthocyanins. To validate their function, the researchers developed an optimized virus-induced gene silencing (VIGS) system capable of suppressing these genes throughout whole fruit tissues. Silencing either gene did not alter total anthocyanin levels, but completely abolished acylated anthocyanin accumulation, indicating that both enzymes are required for the modification process. This result confirms their core regulatory role in pigment acylation and suggests evolutionary diversification of BAHD acyltransferases into anthocyanin-modifying functions.
“Our findings not only pinpoint the genes responsible for anthocyanin acylation, but also establish a rapid functional validation pipeline in blueberry,” the research team stated. “The ability to precisely link metabolic profiles to genetic determinants opens new doors for breeding strategies aimed at improving fruit quality, nutritional functionality, and stability of natural colorants. This represents a significant advance in understanding how bioactive compounds are shaped at the genetic level.”
The identification of VcBAHD-AT1 and VcBAHD-AT4 enables the development of molecular markers to select for cultivars enriched in acylated anthocyanins, potentially leading to blueberries with improved health-promoting properties. Given the enhanced stability and possible improved bioavailability of acylated anthocyanins, these genetic insights also offer opportunities for natural pigment applications in food manufacturing, where color durability is essential. In addition, the optimized VIGS workflow can accelerate functional genomics studies targeting other fruit quality traits, supporting faster breeding cycles and innovation in berry improvement programs.
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References
DOI
Original Source URL
https://doi.org/10.1093/hr/uhaf041
Funding information
This research was supported by the Foundation for Food and Agriculture Research (FFAR) under award number 534667. MI, MAL, MFM, and MAA were also supported by the United States Department of Agriculture National Institute of Food and Agriculture, Hatch project 1008691, and the National Institute of Food and Agriculture, United States Department of Agriculture, under award number 2019–51181–30015, project ‘VacciniumCAP: Leveraging genetic and genomic resources to enable development of blueberry and cranberry cultivars with improved fruit quality attributes’. Partial funding for this project were also provided by the "NCSU Plant Breeding Consortium Small Grants Program", enabled by resources from licensing of improved varieties.
About Horticulture Research
Horticulture Research is an open access journal of Nanjing Agricultural University and ranked number one in the Horticulture category of the Journal Citation Reports ™ from Clarivate, 2023. The journal is committed to publishing original research articles, reviews, perspectives, comments, correspondence articles and letters to the editor related to all major horticultural plants and disciplines, including biotechnology, breeding, cellular and molecular biology, evolution, genetics, inter-species interactions, physiology, and the origination and domestication of crops.