Tomato yellow mystery solved: Discovery of YFT3 gene's role in fruit pigmentation

A recent study has uncovered the genetic basis behind the color of tomato fruits, focusing on the role of the YFT3 gene in carotenoid biosynthesis. This research offers vital insights into how mutations in the YFT3 gene can drastically reduce enzymatic activity, leading to lower carotenoid levels and resulting in yellow-colored fruits. These findings not only deepen our understanding of the molecular mechanisms behind pigment production in tomatoes but also offer potential strategies to enhance both the nutritional value and visual appeal of this staple crop.

Carotenoids are essential for the color and nutritional quality of tomatoes, contributing to the vibrant reds, oranges, and yellows that make the fruit visually appealing, while also providing a rich source of vitamins and antioxidants crucial for human health. However, despite their importance, the intricate biological processes that regulate carotenoid accumulation in tomato fruits remain poorly understood. This gap in knowledge has created an urgent need for research to uncover the genetic and molecular pathways that control carotenoid synthesis. Understanding these mechanisms is essential for developing tomato varieties with enhanced nutritional profiles and richer, more vibrant colors.

Researchers from Shanghai Jiao Tong University have made significant strides in this field, with their findings (DOI: 10.1093/hr/uhae202) published on July 24, 2024, issue of Horticulture Research. The study investigates a tomato mutant with a malfunctioning YFT3 gene, revealing how impaired enzyme activity affects carotenoid accumulation and fruit coloration. This research marks a crucial step in identifying the genetic factors that determine the appearance and nutritional quality of tomatoes.

In this study, the team identified a critical mutation in the YFT3 gene of tomatoes, which encodes an enzyme involved in the isoprenoid biosynthetic pathway. This pathway plays a central role in the production of carotenoids—the pigments responsible for the color and health benefits of many fruits, including tomatoes. Specifically, the Ser126Arg substitution in the YFT3 gene leads to a significant reduction in the enzyme's ability to convert isopentenyl pyrophosphate (IPP) to dimethylallyl pyrophosphate (DMAPP)—a crucial step in carotenoid synthesis. The research demonstrated that the mutated YFT3 allele not only showed reduced enzymatic activity in laboratory conditions but also led to a substantial decrease in carotenoid accumulation in tomato fruits, resulting in a yellow fruit phenotype. These findings highlight the critical role of specific amino acid residues in the enzyme's function and open the door for genetic manipulation aimed at enhancing carotenoid content in tomatoes, potentially leading to improved nutritional value and more vibrant fruit coloration.

Dr. Lingxia Zhao, the lead author of the study, explains, “Our research not only uncovers a key genetic factor influencing tomato fruit color but also provides valuable insights into the complex network of carotenoid biosynthesis. This knowledge could play a pivotal role in the development of tomatoes with enhanced nutritional value and improved aesthetic appeal.” Her remarks emphasize the broader implications of the findings, suggesting that these insights could shape the future of tomato breeding and genetic modification to optimize both the health benefits and visual qualities of the fruit.

The implications of this research extend far beyond the laboratory, offering promising applications for tomato breeding programs designed to enhance fruit quality and nutritional content. By understanding the role of the YFT3 gene, breeders could develop tomato varieties with higher carotenoid levels, improving their health benefits as a dietary source of vitamins and antioxidants. This breakthrough could have significant impacts not only on public health by improving the nutritional profile of tomatoes but also on agricultural sustainability by fostering the development of more resilient and nutritious crops.

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References

DOI

10.1093/hr/uhae202

Original Source URL

https://doi.org/10.1093/hr/uhae202

Funding information

This work was supported by the National Natural Science Foundation of China (32072583, 32372694), Shanghai Collaborative Innovation Center of Agri-Seeds Foundation (ZXWH2150201/010), Shanghai and Kunshan Creation Center of Tomato Novel Germplasm Foundation (SJYY2022-T001), and Collection and Conservation of the Characteristic Crop Germplasm Resource in Kunshan City (Kunshan-AGR-001).

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.