Plant – Microbe Interactions: Leaf Endophytes!

A few Saturdays ago at Park Rapids Farmers Market, we plated leaves to look at the microbial endophytes living inside of them. Then we did some more leaves at Cedar Creek Ecosystem Science Reserve. Find yours below!

Park Rapids Farmers Market

Cedar Creek

Your Microbiome

The Blekhman Lab at UMN studies the human microbiome — that amazing, complex microbial community that lives in and on us! If you visited them at Midtown Farmers Market last Saturday, you got the chance to culture your own microbiome. See the photos below and match up your ID number (e.g., A1, A5) with the ID number in the photo to see how (a portion of) your microbiome looks when grown on an agar plate! There are also some additional lab plates that the Blekhman Lab did to give you an idea of what other microbiome members look like.

Virus Biology at Richfield Farmers Market

By: Amy Kendig

While viruses can cause scary diseases in humans, they are not always “bad”. For example, viruses can help plants withstand extreme conditions and humans fight against diseases. Viruses infect organisms from bacteria to elephants, and are important parts of ecosystems around the world. Last week at the Richfield Farmer’s Market, we talked about what viruses are made out of, who they can infect, and how they are transmitted.

Visitors used microscopes to observe aphids feeding on oat leaves. Aphids are one way that viruses can spread through a crop field or wild grassland. They carry the viruses that I study (Barley Yellow Dwarf Viruses) in order to understand how nutrients in the soil affect plant diseases.


Cross-section drawing of an aphid feeding on plant tissue. It is transmitting viruses known as Barley Yellow Dwarf Viruses (BYDV). Figure source:

While we can’t see viruses with our eyes, scientists have used powerful microscopes to figure out what they look like. Based on these pictures, young scientists built their own models of viruses. They used pipe cleaners to make DNA and Play-Doh to make protein coats because these are two main parts of a virus particle. We talked about what DNA is and how viruses can get inside of hosts. Once we figured out the basics, creativity took over and entirely new viruses were created!



Finally, visitors played a matching game to figure out which viruses are transmitted by which vectors to certain hosts. They learned that the names of viruses can be associated with the name of the host and that there are many types of vectors.



One of my favorite parts of Market Science is learning from the people that stop by. For instance, one visitor taught me that mosquito saliva can act as an anesthetic (causing numbness) when biting humans. This can make disease transmission more successful because we are less likely to swat them away. I spoke with another visitor about treatments for rabies virus that are used where he grew up in India. It was interesting to think about how there are multiple perspectives on virus (and other) biology, and the science I used for these Market Science activities comes from just one of these perspectives.


Red Leaf, Green Leaf: Exploring Plant Pigments

By Laura Nelson

Do you know why leaves change colors in the fall? The answer has to do with chemical compounds in leaves known as pigments. You may have heard of the green pigment chlorophyll. At the Nokomis Market on July 27, visitors explored how other pigments are present in leaves all the time but are invisible until autumn. Seasonal changes, including shorter daylight hours, cause plants to break down chlorophyll which is quite “expensive” in the amount of energy needed to produce it. Visitors explored the importance of chlorophyll in photosynthesis by recreating the photosynthetic cycle on a felt board. When photosynthesis slows in the fall and a plant breaks down chlorophyll into its components, it will recycle these component nutrients. Other pigments that were once hidden become visible because of the breakdown of chlorophyll. The pigments xanthophyll (yellows and browns), carotenoids (orange), and anthocyanins (reds and purples) are the vibrant colors we see showing through in autumn.


To explore the idea hidden pigments, market goers performed chromatography, the process of separating a substance into its components. Visitors separated colors by marking a dot on a piece of chromatography paper, dipping it in water, and observing the water soak up the paper through capillary action. The results showed that secondary colors like green separated into primary colors like blue and yellow. You can perform your own chromatography with markers at home using coffee filters.


Separating leaf pigments takes up to an hour, so market goers prepared their own take-home leaf chromatography kits. Market Scientists provided leaf samples from a common houseplant called Zebrina with bright purple and green leaves. Visitors tore the leaves into small sections, put them in a plastic vial, and covered the leaf bits with a small amount of isopropyl alcohol. Equipped with their own leaf samples, chromatography paper, and instructions, market goers left with science kits to explore leaf pigments. Curious about the results? Take a look at the chromatography paper below. Can you pick out the two primary pigments anthocyanin and chlorophyll?



Visitors separated colors with a prism, but instead of pigments, they saw different wavelengths in the visible light spectrum. Our youngest visitors also enjoyed observing leaf trichomes, or hairs, under a microscope. Thank you to Nokomis Market for welcoming the Market Scientists and for all the visitors who explored leaf colors with us!



Healthy Prairies


Have you ever seen a Minnesota prairie? If you have, you’re lucky! It is such a unique and fascinating ecosystem, but is disappearing at an alarming rate. Minnesota had over 18 million acres of prairie in the late 1800’s, and now only 1% of that remains.

A few scenes from a Minnesota prairie

The Healthy Prairies Project is a UMN research initiative funded by MN LCCMR to help conserve and restore our native prairies.  On Saturday, visitors at the Midtown Farmers Market got to meet the Healthy Prairies team and learn about this precious MN ecosystem! They even got to make their own “seed balls” filled with native perennial grass seeds, which they can take home to grow their own prairie plants.

Making seed balls filled with native MN perennial grass seeds

Perennial prairie grasses like Big Bluestem (Andropogon gerardii) and Sideoats Grama (Bouteloua curtipendula) have very deep roots that help reduce soil erosion, filter water, and store lots of carbon. Plus, they’re extremely drought tolerant!

You can compare the roots of regular turfgrass (far left) and native plants to see that natives have a lot more going on underground!

There are also a whole host of prairie wildflowers that serve as important food sources for lots of pollinators like bees and moths. You can learn more about planting a prairie garden here.

A small bumblebee seeking out nectar and pollen from Purple Coneflower (Echinacea purpurea), a MN native wildflower

But did you know there’s even cool stuff going on inside the leaves of these plants? Every leaf of every plant you see has fungi and bacteria living inside; we call these microbial dwellers leaf endophytes. At the Healthy Prairies Market Science session visitors got to see the huge diversity of fungi that live inside the leaves of some prairie plants.

These Petri dishes are growing fungi collected from leaves of Purple Prairie Clover (Dalea purpurea)

As UMN graduate student Mara DeMers explains,

If plants are filled with fungi and bacteria, just what are those microorganisms doing in there? In fact, different endophytes do different things, and there are MANY different fungi and bacteria that live as endophytes. So the short answer is: Lots of things!

What’s the long answer? Some endophytes can protect their plant hosts from being eaten, or help them survive in hot or dry places. Others might actually be pathogens, but are living as endophytes because some condition isn’t right for them to cause disease. For many endophytes, we still don’t have an answer. Maybe they help the plant, or maybe they hurt the plant, or maybe they don’t affect the plant at all. We don’t know yet!

Plant endophytes are a rapidly developing field in biology, and the Healthy Prairies team is on the forefront of research investigating the roles these microbes play in the prairie.

We hope you enjoyed visiting the Healthy Prairies team at Midtown, and that you’ve thrown your seed balls far and wide! There are lots of prairies you can visit across the state; here are a few to get you started.

Space travelers and the first plants on land- Weird Plants Day at the Market

By: Dr. Daniel Stanton

When people think of plants, they usually think of bright colorful flowers or fields of crops. But plant life is much more diverse than just that, and some of the most exciting and important plants are the less showy little ones that we often overlook. Last Saturday’s Market Science was all about these “weird” plants that don’t have flowers or seeds: lichens, mosses and ferns. Dr Daniel Stanton of the University of Minnesota, who has worked on mosses and lichens around the world, from the Atacama desert to edge of Antarctica was on hand to show examples and answer questions.

Lichens, not truly plants but instead a close partnership (symbiosis) between fungi (which create a protective casing) and algae (which give food-sugars from photosynthesis to the fungi), are some of the toughest organisms on the planet. One variety, well known to anyone who has visited the North Shore and seen the splashes of orange on the rocks, is able survive more than 18 months in the vacuum of space without harm! Another lichen has been shown to be able to survive on the surface of Mars. This amazing toughness come from a “super-power” shared with mosses: lichens can be dried down and spend very long periods “resting” and then recover almost immediately when rewetted.

Lichens like the one covering this rock
Lichens like the one covering this rock are incredibly tough!

The ability to dry up and recover also characterizes a lot of the mosses that were on display. These ancient plants (two times older than the first dinosaurs) were probably among the first to colonize land, and still today we find them in places where no “normal” plant would ever be able to grow. Their tiny spores are able to go long distances and start growing even if there is no soil, and you’ll find them everywhere from tree bark to bare rock outcrops.

Equisetum (Horse Tail) is another "weird plant." It's the only living genus of the whole class Equisetopsida, which 300 million years ago dominated the forest understory around the globe.
Equisetum (Horse Tail) is another “weird plant.” It’s the only living genus of the whole class Equisetopsida, which 300 million years ago dominated forest understories around the globe.

So hopefully next time you see some “colorful smear” on a rock, or a bit of moss below a tree, you stop and look more closely at these small, but beautiful and rugged “weird plants”!

Mantids, roaches, and spiders, oh my! — Entomology Day at the Market

There is an epidemic of entomophobia in our society today — why are so many people afraid of insects?? They’re tiny, almost all of them are harmless to humans, and they’re REALLY COOL! I think the reason folks find insects and spiders so distressing is only because they don’t know that much about them — last Saturday Market Science tried to change that 🙂

We brought in the fantastic entomology outreach group Frenatae from the University of MN to teach market goers all about bugs, spiders, bees, and more. As one of the oldest student groups at UMN, Frenatae knew how to bring in the crowds — with live insects and arachnids!

Despite being so fearsome looking, this vinegaroon (an arachnid) is harmless to humans. Though if aggravated, it may spray some acetic acid (i.e., vinegar) in your direction!
Market Scientist Amanda with her best Lepidopteran buddy, Charlie the Caterpillar (Manduca sexta). Charlie is commonly known as a Tobacco Hornworm, and will metamorphosize into a beautiful Carolina Sphinx Moth.

Also making appearances were a praying mantis, a crew of Madagascar cockroaches, two species of tarantulas, the amazing Death Feigning Beetles, and a scorpion. Even with all these critters, this is very small sampling of the world’s insect diversity — entomologists estimate there are between 2 and 30 million insect species out there! And we depend on them for countless ecological services, even if we don’t realize it.

Visitors had the chance to ask Frenatae entomologists all about the common insects and arachnids we see in Minnesota, and could even pick up some wildflower seeds to attract native pollinators to their yards. Lots of folks enjoyed petting the hissing cockroaches, and peering into the microscope to see some lively springtails.

It was a busy day at Market Science!

Spiders share many characteristics with their 6-legged relatives, but are not insects (see why on our Trivia page). We often think of spiders as dangerous, but did you know that less than 1% pose any threat to humans? And what beautiful webs! If you stopped by on Saturday you may have had a chance to make your own spider and web to take home:

Spiders make all sorts of webs and so can you! Lots of Junior Market Scientists got to take home their own spider and customized web from the MS booth.

So before you step on that next centipede or spider, think about the fascinating creature underfoot, and hopefully you’ll decide to scoop them up in a glass and put them outside. They’re really not scary once you get to know them a bit 🙂

See you next Saturday!

Even the vinegaroons dig our new t-shirts!

Diggin’ Deep with Market Science

Market Science on May 9th was all about the world beneath our feet.


Pick one object around you — it can be your shirt, your tv, your phone, your shoe — and try to trace back its manufacturing without referencing soil. You’ll find it impossible for almost everything in your home! Your shirt? Made of cotton? Grown in soil. How about the milk in the fridge? The cows it came from were fed with vegetable products that grew in soil, and the plastic jug you bought it in was likely manufactured using electricity from a power plant burning coal, which comes from ancient plant material that, you guessed it, relied on soil to grow. Our drinking water gets filtered through the soil, and soil microorganisms recycle organic material into nutrients that can then be reused by plants, and later, us!

Soil is truly one of our most valuable natural resources. Visitors to Soils Day at Market Science were able to look at soil under the microscope to see that it’s incredibly diverse, with large sand grains dwarfing the minuscule clay particles. We learned that the four main ingredients of soil — air, water, minerals, and organic matter — combine in unique “recipes” to create over 70,000 different types of soil in the U.S. alone!IMG_20150509_101115

At the booth we had soil from the banks of the Mississippi (very low in organic matter) and soil from a patch of forest in St. Paul (high in organic matter) — when we poured hydrogen peroxide into these soils, we saw it reacting with the organic matter to form bubbles of carbon dioxide, and we could test which soil contained the most organic material by observing the amount of “bubbling” that occurred.

Soil is also home to a startling diversity of life — one teaspoon of soil can hold over a BILLION individual organisms, from bacteria and fungi to small insects and nematodes. Visitors to the Market Science booth got to take a look at microscopic nematodes under the compound microscope and saw earthworms get HUGE under the dissecting microscope (though there was no dissecting involved!).

We hope you enjoyed getting a little dirty with us here at Market Science — remember: you’re never too old to play in the dirt!