Dartmouth College researchers have uncovered the genetic mechanisms behind the corpse flower’s distinctive heat production and its infamous foul odor. Their study, published in PNAS Nexus on November 4, 2024, identified a previously unknown chemical, putrescine, that contributes to the plant’s smell, and mapped how different parts of the flower work together to create its powerful scent.
A Rare Opportunity for Study
The titan arum, or corpse flower, is known for its overwhelming stench, which draws crowds to greenhouses around the world. However, studying the plant is a challenge because it only blooms once every 5 to 7 years and for a very short time. “The blooms are rare and short-lived, giving us only a small window to observe and study these events,” said G. Eric Schaller, a professor of biological sciences at Dartmouth.
To make the most of this rare opportunity, researchers collected tissue samples during several blooms of “Morphy,” Dartmouth’s 21-year-old corpse flower. They then conducted genetic and chemical analyses to learn more about this unusual plant.
How the Corpse Flower Generates Heat
The corpse flower is not a single bloom, but a cluster of small flowers nestled within a large central stalk called the spadix, which can grow up to 12 feet tall. When it blooms, the plant generates heat, a behavior not seen in many other plants.
The process begins when a petal-like layer at the base, known as the spathe, opens up, forming a deep red or maroon cup around the spadix. The spadix then heats up to around 20 degrees Fahrenheit above the surrounding air temperature. This heat is followed by the release of the flower’s characteristic foul odor.
Discovering the Molecular Mechanisms
Using RNA analysis on nine tissue samples collected over three nights, the researchers found increased activity in genes related to heat production and sulfur metabolism during the bloom. To track chemical changes, the team also employed mass spectrometry.
The analysis revealed high levels of methionine, a sulfur-containing amino acid responsible for producing pungent smells when heated. But the most surprising discovery was the presence of putrescine, a chemical typically found in decaying animal matter. This new finding adds another layer to our understanding of the corpse flower’s complex, rotten smell.
By studying the genetic and chemical processes involved in heat production and scent release, the Dartmouth researchers have uncovered critical insights into one of nature’s most peculiar plants.
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