NEW YORK, Aug 3: While roses are often associated with love and romance, their sharp spikes, or prickles, are more than just a charming feature. These prickles, which protrude from the plant's stems, serve a defensive role by deterring animals from consuming the buds. However, roses are not unique in having this feature. Prickles are also found on other plants, including spider flowers, brambles (which produce raspberries and blackberries), and even common crops such as tomatoes, eggplants, barley, and rice.

A new study published Thursday in the journal Science has uncovered the genetic origins of these prickles, revealing that a single ancient gene family is responsible for their development across a variety of plant species. This research, conducted by an international team of scientists, offers insight into the evolutionary history of prickles and could pave the way for creating prickle-free plant variants.

Contrary to popular belief, roses do not have thorns but rather prickles that emerge from the plant's skin, similar to how hair grows. Prickles have been present for at least 400 million years, dating back to the era of ferns and their relatives. The trait has appeared and vanished at different points throughout evolutionary history.

One of the most diverse plant genera, Solanum—which includes potatoes, tomatoes, and eggplants—first developed prickles approximately 6 million years ago. Today, this genus boasts over 1,000 species worldwide, with around 400 of them known as "spiny solanum" due to their prickles.

The study highlights a phenomenon known as convergent evolution, where similar traits, such as prickles, evolve independently in different species due to similar environmental pressures. This is analogous to the way wings have evolved in various species, including birds, bats, and certain types of squirrels.

Prickles and thorns are evolutionary adaptations designed to protect plants from herbivores, enhance growth, and aid in water retention. The study reveals that an ancient gene family called Lonely Guy (LOG) plays a crucial role in the development of prickles. This gene family regulates the production of a hormone known as cytokinin, which is essential for plant growth and development.

Study coauthor Zachary Lippman, a plant biologist and professor of genetics at Cold Spring Harbor Laboratory, explains that the LOG gene family is responsible for prickles in about 20 different plant species. LOG-related genes are present in all plants, even in early land plants like mosses. The study found that these genes can be switched on and off across different species, suggesting that prickles have been gained and lost independently over time.

The discovery of the LOG gene family provides researchers with valuable tools to explore the ecological role of prickles and their effectiveness as a defense mechanism. According to Tyler Coverdale, an assistant professor of biological sciences at the University of Notre Dame, understanding the role of prickles can shed light on plant defense mechanisms and potentially reveal why certain plants have evolved to have prickles.

With the identification of the gene responsible for prickles, scientists can now use genome editing techniques, such as CRISPR, to create prickle-free variants of plants more efficiently. This advancement could simplify harvesting and improve the availability of certain produce in grocery stores.

Vivian Irish, a plant biologist and professor at Yale University, notes that the study not only enhances our understanding of the evolution of prickles but also provides insights into how plant developmental pathways can be engineered for agricultural improvements.