Posted by Mallory Gehrer
Picture of the flower of Triantha occidentalis (1).
Not every plant soaks up energy and nutrients from sunlight and soil. Sometimes plants can get a craving for meat, too. In the case of this flower, it’s habits of carnivory went unnoticed until just recently, likely due to the fact that it doesn’t quite look like the stereotypical carnivorous plant. This flower might look familiar to some as it is a species native to the west coast and pacific northwest. It even grows in city centers, being very resilient to urban life.
This species of false asphodel happens to snack on small insects, digesting their bodies for important nutrients instead of drawing it all from the soil. Carnivory in plants evolved as a way to live in nutrient poor soils. But how exactly did researchers from the University of British Columbia figure this out, and how does a plant even digest a bug anyways (2)? They used a little trick called nitrogen-15 tracing to first determine if the flower truly was a carnivore. If the flower got a majority of its nitrogen from bugs instead of the soil, then it technically would be carnivorous.
To measure and predict the amount of nitrogen passing through a plant, a type of Monte Carlo simulation is carried out (3) Using these models, they found that 64% of nitrogen came from bugs, which was consistent with other known carnivorous plants (4). One of the reasons this flower went unnoticed for so long was because the Triantha occidentalis uses a unique method to trap its prey. Small, sticky hairs cover the stems of the plant, and they secrete phosphatase, a common secretion in carnivorous plants that digests prey. Phosphatase removes phosphate groups from proteins, and other enzymatic secretions help the flower extract nitrogen and sulfur as well (5).
Sticky hairs on the stem of the Triantha occidentalis (2).
The Triantha occidentalis is so far the only flower that captures bugs on the stem, rather than in an insect trap. The researchers think that, like an insect trap, having small sticky hairs allows the species to trap small, non-pollinating bugs, while larger bugs and pollinators do not get trapped. Otherwise, the plant would be unlikely to spread without a pollinator. What digests the small bugs is phosphatase, an enzyme that cleaves phosphoric acids on larger substrates into phosphate ions and alcohols. It requires water to react, so it is a type of hydrolase.
By using these methods to track nutrient absorption and by identifying new types of bug-catching methods, researchers can find more types of carnivorous plants, and hopefully better understand the environmental conditions and mutations that lead plants to carnivory!
[1] Sweatt, B. (n.d.). Triantha occidentalis. Calflora Observation. Retrieved October 19, 2021, from https://www.calflora.org/entry/occdetail.html?seq_num=mu5941.
[2] Chambers, J. (2021, August 18). A well-known wildflower turns out to be a secret carnivore. Science News. Retrieved October 19, 2021, from https://www.sciencenews.org/article/wildflower-carnivore-plant-sticky-hair-insect-trap.
[3] Tobias, R., Huygens, D., Staelens, J., Müller, C., & Boeckx, P. (n.d.). Advances in N-15-tracing experiments: New Labelling and Data Analysis Approaches. CORE. Retrieved October 19, 2021, from https://core.ac.uk/display/55890295.
[4] Lin, Q., Ané, C., Givnish, T. J., & Graham, S. W. (2021, August 17). A new carnivorous plant lineage (Triantha) with a unique sticky-inflorescence trap. PNAS. Retrieved October 19, 2021, from https://www.pnas.org/content/118/33/e2022724118.
[5] UCSB Science Line. (n.d.). Retrieved October 19, 2021, from http://scienceline.ucsb.edu/getkey.php?key=4884.
Your title and first graphic are attention grabbing. Your opening paragraph is clear, to the point and tantalizing. Your first sentence should, perhaps, have some sort of qualification like, "Not every plant soaks up all of its energy and nutrients...." The introduction of isotopic labelling is done effectively. That and the equation give a good sense of the science without too much overwhelming detail. I suppose you found this in the Calflora source, an interesting if not perhaps really widely read source. Overall an effective and engaging post.
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