PLANTING WONDERFUL IDEAS

By Pam Eastlick

Welcome to The Deep science and technology column where we cover topics from the deep sea to deep space and beyond.

Greetings everyone! Well, I thought today we’d visit a file we don’t delve into very often. It’s a shame really because if it wasn’t for these Earth inhabitants, humans and the rest of the animals wouldn’t be here. It is, of course, the plants. If the Sun doesn’t shine and the plants don’t keep cranking out that oxygen, humans and all the rest of the animals are quite literally dead meat. We do tend to forget how much we depend on the plants.

Although our later excursions in this column today will be into the plant kingdom, our first story is about a group of living things that most of us tend to think of as plants. After all, they don’t move and we eat some of them, so that makes them plants right? Well no, our first story is about several species of the fungi and the fungi (we call many of them mushrooms) are actually more closely related to animals than plants.

One of my fondest memories is of the Ecology field trip I took several years ago. I had already graduated so I no longer had to worry about taking notes or doing surveys, I just got to enjoy the terrain.

Most of us don’t go into the jungle at night, but on that trip Mariano and I took flashlights and stepped into a whole new world. One of the things we found was an entire log that was lit up like a Christmas tree. It was full of luminescent mushrooms and I got to answer a question I’d always wondered about. Is it just the fruiting bodies (the mushrooms) that glow or is it the whole organism including the hyphae (the roots)? Read on for the answer!

LIGHTING UP THE NIGHT

Seven new glow-in-the-dark mushroom species have been discovered, increasing the number of known luminescent fungi species from 64 to 71. The paper was published in the journal Mycologia, and the new finds include two new species named after movements in Mozart’s Requiem. The discoveries also shed light on the evolution of luminescence, adding to the number of known lineages in the fungi ‘family tree’ where luminescence has been reported.

Researchers from San Francisco State University discovered the fungi in Belize, Brazil, Dominican Republic, Jamaica, Japan, Malaysia and Puerto Rico. The discoveries include four species new to science and three new reports of luminescence in known species. Three quarters of glowing mushrooms, including the species described in the study, belong to the Mycena genus, a group of mushrooms that feed off and decompose organic matter as a source of nutrients to sustain their growth.

"What interests us is that within Mycena, the luminescent species come from 16 different lineages, which suggests that luminescence evolved at a single point and some species later lost the ability to glow," said Dennis Desjardin, lead author of the study. He believes that some fungi glow in order to attract nocturnal animals that aid in the dispersal of the mushroom’s spores, which are similar to seeds and are capable of growing into new organisms.

The newly discovered fungi glow constantly, emitting a bright, yellowish-green light, and are tiny, with caps smaller than one centimeter across. The new species have been named Mycena luxaeterna (eternal light) and Mycena luxperpetua (perpetual light), names inspired by Mozart’s Requiem and the fact that these mushrooms glow 24 hours a day. To date, Desjardin has discovered more than 200 new fungi species and together with these latest findings, has discovered nearly a quarter of all known luminescent fungi.

A new luminescent fungus, Mycena luxaeterna. The species was collected in Sao Paulo, Brazil and was found on sticks in an Atlantic forest habitat. These mushrooms are tiny with each cap measuring less than 8 millimeters in diameter and their stems have a jelly-like texture (Credit: Cassius V. Stevani, Chemistry Institute, University of Sao Paulo)

And based on my personal experience, yes the hyphae do glow in the luminescent mushrooms on Guam. Are they the same species described in the article? Who knows?

But I’ll tell you something else interesting. If you go out into the jungle at night and turn off your flashlight and wait for about 20 minutes until your eyes completely adjust to the darkness, you’ll discover something REALLY interesting. After a while, the entire forest floor lights up with an eerie, very faint, blue-green glow. As near as we’re able to tell, this is caused by luminescent bacteria that are decomposing the dead plant material that’s present all over the forest floor. It’s an amazing sight!

And now for a little excursion into the world of plants, but plants as you’ve never thought of them before!

KILLER PETUNIAS?

People have always been interested in the so-called carnivorous plants or plants that eat insects and other animals. Although we know there are no man-eating plants, they continue to appear in films (Audrey II in Little Shop of Horrors) and books (Tentacula in the Harry Potter series). The Japanese cartoon Pokémon has several characters based on carnivorous plants (Bellsprout, Weepinbell and Victreebell).

Carnivorous plants fascinated Charles Darwin, and he and his friend Sir Joseph Hooker who was Director of the Royal Botanic Gardens, Kew had an extensive correspondence concerning them. Darwin’s book Insectivorous Plants played a large part in the acceptance of the idea that plants could eat animals. Before it was published, many botanists (including Linnaeus) refused to accept it was possible.

Since Darwin’s time, several groups have been recognized as carnivorous plants including sundews, Venus flytraps and pitcher plants. Although Guam has no Venus flytraps or pitcher plants, Palau has several pitcher plant species including some that are found only on Palau. We do however have a lovely little savanna plant here on Guam with the marvelous habit of lassoing worms called nematodes with its roots and then growing into them and sucking them dry.

Various other plants have been suggested as possible carnivores by some scientists, but their ideas have not gained wide acceptance. One problem is that the making a definition of what constitutes carnivory in plants is a challenge, and botanists include or exclude groups of plants on the basis of different sets of criteria.

Now botanists from the Royal Botanic Gardens, Kew and the Natural History Museum in England have published a paper that says carnivorous behavior in plants is far more widespread than previously thought. In the paper they state that many commonly grown plants including flowers like petunias, show some of the characteristics of being "meat eaters."

Many plants, like petunias and potatoes have sticky hairs that trap insects, and some species of campion (a commonly planted ornamental flower in temperate zones) have the common name ‘catchfly’ for the same reason. However, unlike the commonly accepted carnivorous plants, these plants don’t seem to have the ability to digest the insects they trap or to absorb the breakdown products.

Some of them may however, and Professor Mark Chase, Keeper of the Jodrell Laboratory at the Royal Botanic Gardens, Kew says, "Although a man-eating tree is fictional, many commonly grown plants may turn out to be cryptic carnivores, by absorbing through their roots the breakdown products of the animals that they ensnare. We may be surrounded by many more murderous plants than we think."

Fading petunias still hold interest for this fly. (Credit: iStockphoto/Denice Breaux)

Hmmmm. . . . killer petunias, eh? And in case you don’t think that’s weird enough, try this story on for size! Plants are plants and animals are animals, right? They conduct their business in totally different ways using totally different chemicals to do it, right? Well . . . maybe.

WHAT’S THAT DOING THERE??

In a paper published in the journal of the American Chemical Society, researchers have reported the first discovery of the female sex hormone progesterone in a plant. Until now, scientists thought that only animals could make progesterone. Progesterone is a hormone secreted by the ovaries that prepares the uterus for pregnancy and maintains pregnancy. A synthetic version, progestin, is used in birth control pills and other medications.

This discovery has mystified the researchers who discovered it. They speculate that progesterone, like other hormones, might be an ancient bioregulator that evolved billions of years ago, before the appearance of modern plants and animals. The new discovery may change scientific understanding of the evolution and function of progesterone in living things.

Scientists had previously identified progesterone-like substances in plants and speculated that the hormone itself could exist in plants but this is the first recorded instance of the actual hormone in plants. So, in what exotic plant did they make their discovery? They found progesterone in the leaves of the English walnut tree. They also identified five new progesterone-related steroids in a plant belonging to the buttercup family.

Leaves of the walnut tree contain progesterone, the female sex hormone, discovered for the first time in a plant. (Credit: iStockphoto)

So . . . plants that eat animals, plants that have animal hormones. What’s next?

Well, we all know the importance of plants. They make our oxygen and ultimately they make all our food. But they will become even more important in the future and one of the latest findings will dramatically affect us here on Guam. Maybe.

HOW TO SAVE THE WORLD

An article in the current issue of Global Change Biology Bioenergy reveals that a plant called Miscanthus could effectively reduce our dependence on fossil fuels, while lowering atmospheric carbon dioxide.

Using a simulation tool that models the future global climate, researchers predict that the carbon that is released into the atmosphere from the loss of natural vegetation will be paid back by Miscanthus within 30 years. Previous estimates for other liquid biofuels, such as corn ethanol, were estimated to take 167 to 420 years to pay back their carbon debt.

The global concern over climate change has challenged researchers to explore ways to mitigate the damage we are doing to our environment. They are looking more closely at energy crops, like Miscanthus, to replace our need for fossil fuels like natural gas and oil, which raise atmospheric CO₂ concentrations.

According to John Hughes, UK Met Office Research Scientist, "Our study demonstrates the huge potential of energy crops, in particular of Miscanthus. Also, by scaling the results up to the global scale as we do in this study we are developing a new set of tools for evaluating energy crops."

So . . . ladies and gentlemen, just how does this wonderful new miracle plant relate to us here on Guam? Why does it put our island at the forefront of the race to replace our need for fossil fuels? What is this miracle plant?

You’re all familiar with it. Miscanthus is . . . . swordgrass!!!