Unlocking blueberry quality: the role of cuticular waxes

New research uncovers the molecular regulation of cuticular wax biosynthesis in blueberries, highlighting how these natural coatings affect crucial fruit quality traits like water loss and surface color during ripening and storage, providing valuable insights for improving blueberry quality.

Cuticular waxes protect fruit by reducing water loss and influencing color. They are a mix of very-long-chain aliphatic and cyclic compounds, varying among fruit species. In blueberries, triterpenoids and β-diketones are most abundant. However, their biosynthesis and genetic regulation are not well understood. Thus, a comprehensive study was needed to explore the transcriptional regulation of cuticular wax biosynthesis and its impact on fruit quality.

Researchers from the University of British Columbia, Canada’s Michael Smith Genome Sciences Centre, and the British Columbia Blueberry Council have conducted a study on cuticular wax biosynthesis in northern highbush blueberries. The study (DOI: 10.1093/hr/uhae004) was published on January 9, 2024, in the journal Horticulture Research. It investigates how transcriptional regulation of cuticular wax deposition affects fruit water loss and surface color during ripening and postharvest storage. By analyzing transcriptome changes and metabolite profiles, the study aims to identify key genes involved in wax biosynthesis and provide insights into improving blueberry fruit quality through wax management.

The study revealed that cuticular wax content in blueberries changes significantly during ripening and postharvest storage. Initially, total wax content decreases as the fruit ripens, attributed mainly to fruit expansion. However, during storage, there is a notable increase in wax content, indicating de novo biosynthesis. The research identified 54 different wax compounds, with triterpenoids being the most abundant, followed by β-diketones. Transcriptome analysis highlighted a network of genes involved in cuticular wax biosynthesis. Notably, five OSC-Like genes were identified, encoding enzymes responsible for triterpenoid production. The expression of these genes, along with three CYP716A-like genes, correlated with the accumulation of major wax compounds like oleanolic acid and ursolic acid. Exogenous application of abscisic acid (ABA) was found to induce the expression of triterpenoid biosynthetic genes, leading to increased wax content and altered wax composition. This resulted in reduced fruit water loss and enhanced surface color, especially increased lightness. The study provides a comprehensive understanding of the molecular mechanisms underlying cuticular wax biosynthesis in blueberries. It highlights the potential of manipulating wax biosynthesis pathways to improve fruit quality traits, such as reduced water loss and enhanced visual appeal, during postharvest storage.

Dr. Simone Castellarin, the corresponding author, stated, "Our findings shed light on the complex regulatory networks controlling cuticular wax biosynthesis in blueberries. By understanding these molecular mechanisms, we can develop strategies to enhance fruit quality and extend shelf life, benefiting both producers and consumers."

The study's insights are crucial for the blueberry industry. Manipulating wax biosynthesis genes can improve fruit quality traits like reduced water loss and better surface color, extending shelf life and marketability. These findings can also benefit other fruits. Future research can focus on breeding or genetic engineering to optimize wax composition, enhancing fruit resilience and quality during storage.

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References

DOI

10.1093/hr/uhae004

Original Source URL

https://doi.org/10.1093/hr/uhae004

Funding information

Christina Latza, and Spencer Marshall for technical support. Funding for this work was provided with the NIFA Award 2016-70016-24844 and 2016-10974 and USDA-ARS base funds.

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, 2022. 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.