Seed Snot
In the 1980s, America was introduced to the idea that a house plant could be more than a decoration, it could be a pet. The Chia Pet® was a clay figurine with a grooved surface and an infectious jingle that appeared in many a school and home all for the low price of $9.99 (postage and handling not included). Moistened chia seeds (Salvia columbariae) were carefully applied to the grooved areas of the figurine and in no time at all, the clay hedgehog, cat or dog would sprout thick green “fur.” It seemed like magic, but the true magic of the chia pet lay not in the whimsical figurines, sea of tiny sprouts or ear-worm jingle. The true magic of a Chia Pet® was its plentiful mucus.
A Chia Pet® only works if one is able to spread an even lawn of chia seeds over the desired area, and what makes this lawn possible? plant snot, more accurately known as mucilage. Mucilage is a mixture of sugars secreted by the outermost layer of cells in the seed coat. This mucilage is deposited behind the cell wall. When a seed comes in contact with water, the mucilage absorbs moisture, expands and extrudes itself out around the seed creating a protective gel.
This thick, glue-like gel is what binds the chia seeds together and sticks them to the figure’s surface creating an even lawn. If you’re a fan of overnight oats, it’s also the reason this popular breakfast has a creamy, pudding-like texture (mmmmm . . . plant mucus). But Chia Pets® and breakfast aside, plant mucilage can do so much more.
In some plants, seed coat mucilage is involved in dispersal. It can help prevent seeds from being washed away by rainwater by adhering them to soil particles. It can also absorb enough water to help seeds sink rather than float away. And when water is scarce, a well-hydrated coat of mucilage can help seeds germinate or even condition the soil to enhance water retention. A good layer of seed snot can also protect animal-dispersed seeds from the corrosive effects of digestion and safe-guard other seeds from grain-eating pests, like ants.
And when it comes to industry, the potential of seed coat mucilage is vast. It has been used as a gelling agent in food, a stabilizing agent to improve shelf-life and a source of biodegradable packaging. It has been used to encapsulate drugs for delivery, lubricate drills, protect steel from corrosion and clean the environment of pollutants. There is also the potential to genetically engineer plants to secrete valuable polymers and proteins in their mucilage. If only my mucus was so useful!
So remember, While the Chia Pet® was a brilliant, global, marketing phenomenon, making it all possible was a magical and copious amount of mucus.
Brian Rutter, PhD, is the cofounder of Hundredfold Video and plant biologist working for 2Blades at the University of Minnesota. Subscribe to our newsletter to receive our “Sower Stories – Odd Facts About Plants” and video production tips in your inbox every month!
Works Cited:
Tsai, Allen Yi-Lun, Robert McGee, Gillian H. Dean, George W. Haughn, and Shinichiro Sawa. "Seed mucilage: biological functions and potential applications in biotechnology." Plant and Cell Physiology 62, no. 12 (2021): 1847-1857.
