Water drawn through the hollow stem of a living Equisetum plant, horsetail, has registered the most extreme oxygen isotope signature ever measured in any terrestrial material.
That discovery stretches the known chemical limits of Earth’s water and forces scientists to reconsider how plants, fossils, and even desert climates record the passage of evaporation.
By sampling water from the bottom to the tip, Zachary Sharp, Ph.D., at the University of New Mexico demonstrated that the stem itself steadily concentrates heavy oxygen as moisture escapes into dry air.
Values that began within a typical natural range at the base climbed to levels so enriched at the tip that they exceeded every prior terrestrial measurement.
Because that chemical transformation unfolds inside a single plant rather than in an extreme environment, the finding demands a closer look at how evaporation reshapes water long before it reaches a leaf.
Evaporation up the stem
Evaporation kept pulling water out of the stem as it rose, even before reaching any leafy branches.
As droplets escaped through the stem wall, lighter water molecules left first, so heavier oxygen stayed behind.
Each higher segment started with already-enriched water, then lost more to air, building an extreme gradient toward the tip.
Dry wind and heat can push that process harder, which helps explain odd oxygen data from desert plants.
Oxygen atoms as clues
Oxygen in water carries a chemical signature that scientists use to track where moisture came from and what happened next.
A water sample holds more than one kind of oxygen, and isotopes – atoms of one element with different weights – mark that mix.
When water dries, molecules with lighter oxygen escape first, and the leftover liquid keeps heavier oxygen through evaporation.
Without careful interpretation, that simple sorting can make a lake, a leaf, or a fossil look wetter or drier than it was.
Three oxygen signals
Three separate oxygen versions in the same water drop let scientists tell whether evaporation or source water drove a change.
Sharp’s group tracked three versions of oxygen at once, following how each one changed together in the water moving through the stem.
That extra layer matters because heavy oxygen is rare, and small biases can hide when only one ratio is measured.
With three signals at once, the team could test plant-water models in a way ordinary measurements cannot.
Beyond Earth’s range
Horsetails have a fossil record reaching to the Devonian, a period about 400 million years ago, which defines their long lineage.
In smooth horsetail stem water, the share of heavier oxygen climbed sharply from the base to the tip, reaching levels no one had measured before in a living plant.
“If I found this sample, I would say this is from a meteorite,” said Sharp.
By stretching the known oxygen range across Earth and the solar system fivefold, the results gave modelers a hard boundary
Website: plantscientist.org
Nomination Link
Registration Link
Here with connected:
Follow the Plant Scientist Awards channel on WhatsApp:
Comments
Post a Comment