Roses and their thorns: “LONELY GUY” responsible for prickles on plants
Prickles are features on many plants, perhaps most famously, thorns of roses, as featured in many fairytale stories. Why do some plants, even those that seem unrelated share this thorny similarity? In revolutionary research, scientists show Lonely Guy is behind it.
In the fairytale Sleeping Beauty, the thorns are thought to represent both danger and protection. At first the thorn seems harmless in the enchanted forest but then serves as a sign of problems ahead when used as part of the villain’s curse, growing around the tower that keeps the sleeping princes inside.
The spindle thorn pricks the character Aurora before her life takes a new turn, writer Kelly N. Jane described on how on the thorns from the story inspired her. Artistic, poetic imagery involving thorns are often depicted as rose thorns. The contrast of a beautiful rose with elegant petals is sharp against its prickly, stem.
In nature, prickles are a defence strategy employed by some plants. Most natural roses in particular use this strategy. “Plants like roses have evolved large thorns to avoid being eaten, while plants like cacti have evolved thin spines. These adaptations protect plants from damage from pests and from disease from pathogens carried by pests.” an article states on how plants defend themselves.
Breakthrough to a ‘prickly’ evolution
Roses are not the only plants using these defences, they are present even in some eggplant and rice crops. They evolved in many species across the plant kingdom mainly to ward off herbivores from eating them. Biologists have wondered how the prickly trait appears so often in species that are so unrelated, from rice to the rose.
A breakthrough discovery has recently been made by Cold Spring Harbor Laboratory (CSHL) who found the same ancient gene family that cause prickles in certain species of plant, despite them being really distantly related across a gap of millions of years of evolutionary history.
Postdoc James Satterlee got curious about this while touring a field grown by his advisor Prof. Zachary Lippman who grows hundreds of nightshades including potatoes, eggplants and potatoes.
“I noticed many had very prominent prickles. So, I asked, ‘What do we know about that? What’s going on with this adaptation?’ It turns out we knew almost nothing," Satterlee remembered.
Analysing the LONELY GUY gene
Collaborating with researchers in Spain, Satterlee analysed eggplants, to find the LONELY GUY (LOG) gene. LOG genes appeared to correlate with certain prickles in egg plants though they were normally considered responsible for a hormone involved in cell division.
Satterlee and his supervisor questioned: Could LOG-related genes be responsible for prickle gains and losses across multiple plants over millions of years?
They looked at previous research and consulted experts, also working with the New York Botanical Garden to examine specimens that had or did not have prickles. One colleague managed to suppress prickles in roses. Another eliminated it in desert raisins. In the end, the collaboration associated LOG related genes with prickles in about 20 species.
Identifying the LOG gene does not only help genetically engineer plants without prickles, it adds understanding to the evolution of plants, particularly how those that seem unrelated can show these traits.
“You’re really asking about life in general—evolution of traits. How do they emerge? How are they modified? What are the underlying mechanisms? What can we learn about things we take for granted?” Lippman said.
Perhaps this could make lesser known species like the desert raisin more widely grown by horticulturists and more available in the food market.
Source of the news:
Satterlee et al (2024). Convergent evolution of plant prickles by repeated gene co-option over deep time. Science. DOI: 10.1126/science.ado1663