Unlocking the secrets of plant scent: how terpene synthases drive floral diversity
image: Expression of TPSs in different organs of two model angiosperms and one well-known medicinal angiosperm.
Credit: Horticulture Research
A recent study reveals how the expansion and functional divergence of terpene synthase genes (TPSs) in flowering plants (angiosperms) have driven the astonishing diversity of terpenes—critical compounds involved in plant defense, floral scents, and fruit flavors. Researchers analyzed 222 functionally characterized TPSs across 24 species and uncovered key evolutionary patterns, shedding light on the genetic mechanisms behind terpene diversity. This study lays the groundwork for future research into plant metabolism and adaptation.
Terpenes are among the most abundant and diverse natural compounds produced by plants. These compounds serve a range of vital ecological functions, such as attracting pollinators, repelling herbivores, and defending against pathogens. Despite their ecological importance, the evolutionary processes driving the diversity of terpenes remain poorly understood. Terpene synthases (TPSs) are the enzymes responsible for synthesizing these compounds, yet how these genes have evolved to produce such an array of terpenes is still a mystery. This knowledge gap has driven the need for further exploration into the evolutionary dynamics and functional diversity of TPS genes in angiosperms.
Published (DOI: 10.1093/hr/uhae272) on September 25, 2024, in Horticulture Research, this comprehensive study by a team from Zhejiang University and Yazhouwan National Laboratory uncovers significant evolutionary patterns in terpene synthase genes across angiosperms. By analyzing 222 TPS genes from 24 species, the research reveals how gene duplication and functional divergence have enabled plants to produce an impressive range of terpenes—compounds vital for plant survival and ecological interactions.
The study focused on the catalytic products of the 222 TPS genes, revealing that the TPS-a, TPS-b, and TPS-g subfamilies have undergone significant expansion in angiosperms. These subfamilies are responsible for producing a variety of terpenes, including monoterpenes, sesquiterpenes, diterpenes, and sesterterpenes. The TPS-a subfamily, unique to angiosperms, exhibited a notable species-specific clustering, pointing to a phenomenon of species-specific expansions. For instance, in tomatoes, 34 TPS genes were identified, responsible for generating 8 monoterpenes, 19 sesquiterpenes, and 4 diterpenes. The research also demonstrated that many TPS genes are multifunctional, showing bifunctional or even trifunctional activity in vitro, while their functions in vivo are often influenced by factors such as subcellular localization and substrate availability. This functional diversification allows plants to produce terpenes with specific ecological roles—whether in attracting pollinators or defending against pests. The study also highlighted the significance of TPS genes in the production of medicinal compounds like taxol, a diterpene drug, and valencene, a sesquiterpene used in the pharmaceutical and cosmetics industries.
"This study provides a comprehensive understanding of how terpene synthase genes have evolved to produce the vast chemical diversity seen in flowering plants," said Dr. Xiuyun Wang, co-author of the study. "By uncovering the evolutionary patterns and functional divergence of TPS genes, we can better understand how plants adapt to their environments and interact with other organisms."
The findings of this research have profound implications for both fundamental and applied sciences. Understanding the evolutionary mechanisms behind terpene diversity could facilitate the development of plant varieties with enhanced resistance to pests and diseases, as well as improved floral scents and fruit flavors. Moreover, this study opens new pathways for biotechnological applications, particularly in the production of valuable terpenes used in pharmaceuticals, cosmetics, and food industries. By harnessing the insights into TPS gene functions, researchers could engineer plants to yield higher quantities of specific terpenes, leading to more sustainable and efficient production methods for these economically significant compounds.
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References
DOI
Original Source URL
https://doi.org/10.1093/hr/uhae272
Funding information
This work was supported by the National Natural Science Foundation of China (32371937, 32272750) and Zhejiang Provincial Natural Science Foundation of China (LY24C160003).
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.