Did Mosses Ruin the Planet?

The mosses crept out of the ocean, covering the bare rocks on our desolate planet over 400 million years ago. They sped up the chemical weathering of the rocks and decreased atmospheric carbon dioxide. These nefarious changes triggered glaciation events and a mass marine extinction! Muahahaha...... (yes mosses have an evil laugh) and that is how mosses conquered the land.

A couple of weeks ago, research was published examining the above scenario. The researchers carried out an experiment where they examined the ability of the moss Physcomitrella patens to weather rocks. One of the thoughts was that since mosses do not have true roots they might not alter substrates, such as rocks, in a similar manner. However, they found that the mosses secreted several different organic acids, just like vascular plants. Thus they have the ability to break down and weather rocks. This secretion of organic acids by mosses was not something I had heard about before. Their experiment only examined weathering with and without mosses. But when colonizing land the mosses were not alone. They would have been accompanied by fungi too. The researchers anticipate that the mosses in conjunction with fungal symbionts may even have greater weathering abilities!

Overall I think that it is a really interesting study connecting the colonization of land by mosses to historic patterns of climate change. It shows just how powerful and important plants are for life on our planet! 

Timothy M. Lenton, Michael Crouch, Martin Johnson, Nuno Pires, and Liam Dolan. 2012. First plants cooled the Ordovician. Nature Geoscience 5:86–89.

This post was inspired by a friend who sent me a link to this sarcastic and funny article about this research. I take mild offense to the author calling the mosses names, but otherwise I enjoyed the piece. Thanks Emily!

Not the Model of Monophyly

Physcomitrella patens is our little model organism moss. It has recently had all of its DNA sequenced. Think the human genome project, but for mosses. The speed at which scientific information is transmitted has been greatly increased by the internet. Some scientific journals even publish papers online before they even come out in print. One of these articles in the journal Evolution focuses on the genus Physcomitrella and some of its closest relatives.

Stuart F. McDaniel, Mark von Stackelberg, Sandra Richardt, Ralph S. Quatrano, Ralf Reski, and Stefan A. Rensing. 2009. The Speciation History of the Physcomitrium-Physcomitrella Species Complex. Evolution. 000:000-000. 

Mosses were collected and identified as a particular species by their morphology (their outward appearance to the eye). Using similarities in appearance as an initial hypothesis for species relationships is often where scientists start. These hypotheses were then tested using DNA data to examine relationships among the moss species.

The Bottom Line - All moss populations that are identified as members of the genus  Physcomitrella were not found to be each others closest relatives using DNA information.

Thus the genus does not descend from a single common ancestor. Species or genera that do descend from a single common ancestor are said to be monophyletic or to demonstrate monophyly. Often this is a rule that is used when determining the names of organisms. Think of a genealogy. If you traced back to your grandmother and then you diagrammed all of her children and their children and their children, everyone who is descendant from her by blood, not marriage, you would have a monophyletic group. It works the same way in plants and in the same genus all the members hopefully form a monophyletic group.    

Since the genus Physcomitrella is not monophyletic, name changes are in order with some of these species needing to me moved into a different genus. Their data also show that some of the species are forming hybrids. Crossing a horse with a donkey to get a mule would be an example of a hybrid you might know. However unlike a mule, which cannot reproduce, some of these hybrid species are able to make offspring and continue their reproductive lines.

Their paper explores a basic question that I am very interested in: Are plants that look the same morphologically actually each other's closest relatives? Or have plants that look the same evolved from different ancestors?

Japan, a Moss Walk, a New Website, and Busyness Galore!

Apologies for my recent lack of posting. I am currently in the throes of preparing for a trip to Japan. I was awarded a summer internship through the National Science Foundation's (NSF) East Asia Pacific Summer Institute (EAPSI). I will be spending 10-weeks in Japan working with Dr. Hasebe's lab group at the National Institute for Basic Biology in Okazaki. I will be working with some mutant strains of Physcomitrella patens and running experiments on them. Yes you heard it right, Mutant Mosses. Now I can truly become a mad scientist with a cackling laugh and messy hair! Not to worry though the mutants will not be leaving the lab and they would not try to take over and conquer the world even if they did manage to escape.

I will have internet access while I am in the lab, so I am hoping to keep up with blog posts from Japan. I am planning to visit the city of Kyoto where there are a number of temples that are surrounded by moss gardens. I am hoping to stretch my camera's legs/lens from its photo taking hiatus and get some pretty pictures to post on the blog. I will also be in a number of major cities and it is always fun to hunt for urban mosses. They can grow in some of the oddest nooks and crannies. Additionally, there will be a workshop all about cool lab techniques for Physcomitrella patens held at the lab I will be visiting while in Japan. It should be a great learning experience and put me in touch will many moss researchers across the country. Hopefully I will have fun stories about the mosses and the moss biologists that I meet over the summer.

Also I have updated my personal University Webpage and it has a whole new look. Check it out and let me know what you think. Any comments or critiques are welcome. I have to say a special thanks to my sister who is a graphic designer and gave me assistance/pointers when making the website.

Finally, before I leave I will be leading a short moss walk this upcoming Saturday (June 14th) 11am-12noon at the Goodwin Conservation Center in Hampton, Connecticut, located in the James L. Goodwin State Forest. This is the 4th year that I will be leading a walk at Goodwin, but the last year that I will be working with Emily Komiskey, one of the outdoor educators who is also a graduate student at UConn. Goodwin just won't be the same without you Em! On Saturday the weather forecast is looking much more comfortable than today, partly cloudy skies and 79F for the high. Hope to see you there!

Click here for a link to more details and directions to the moss walk at Goodwin.

Moss Bioreactor

So you might have heard of a bioreactor before, but what does a bioreactor actually do? According Merriam-Webster a bioreactor is "a device in which living organisms (typically bacteria) synthesize useful substances or breakdown harmful ones." A number of biopharmaceuticals are made in this way, using either bacteria or mammal cells. Genes to make specific proteins are inserted into the cells and then they produce these proteins in massive quantities.

Recently they have starting using the moss Physcomitrella patens in conjunction with bioreactor technology. Much of this research is happening in Dr. Ralph Reski's lab in Freiburg, Germany. We met some of the researchers working in his lab at the Physcomitrella workshop that I attended this past March. They are working in conjunction with researchers in the pharmaceutical industry to optimize this technique.

It is pretty interesting that they are able to use mosses for this practical application. Who would have guessed?


Below the fold are several scientific papers that review this process and recent innovations in moss bioreactors. The third article has an amazing color photo of a moss bioreactor!



1) Decker, E.L., Reski, R. (2008): Current achievements in the production of complex biopharmaceuticals with moss bioreactor. Bioprocess and Biosystems Engineering 31, 3-9.

2) Decker, E.L., R. Reski (2007): Moss bioreactors producing improved biopharmaceuticals. Current Opinion in Biotechnology 18, 393-398.

3) Decker, E.L., G. Gorr, R. Reski (2003): Moss - An innovative tool for protein production. BioForum Europe 7, 96-97.

Back From Germany

The trip went really well. We learned a lot about the Physcomitrella Genome databases after arriving at the hotel. After the rain we had a tour around the city. The part of Freiburg that we were introduced to was the old historic part of town. We walked through the third city graveyard. It was in use from the mid 1600's to the late 1800's. Now it is a park. There and how to use them, but I won't belabor the technical details. It was cloudy and rainy for the first part of the trip, but we did have this great rainbow were quite a few mosses tucked next to the gravestones and on the rock wall surrounding the graveyard. I didn't get the chance to take any up close shots or to identify any species but I did see some German mosses.

Our tour also included a walk through the center of the old city and the open square that surrounds the cathedral. They have a market in this area of town daily. When we arrived in the square late in the day most of the booths were taken down. A few flower stands and the bratwurst stand were the last ones open. We didn't buy any flowers, because 1) you can't bring them back into the US and 2) I study mosses. It would be a betrayal to purchase gaudy angiosperms in Germany when we didn't really have a chance to fully appreciate the native mosses in the surrounding mountainsides. However we did partake in the bratwurst and the awesome curry ketchup, which I brought back as a souvenir.

Overall it was a whirlwind trip. We were in Germany for only three days. I would definitely like to return for a longer period of time and to focus on collecting mosses in the field.

Off to Germany

I am heading to Freiburg, Germany on Saturday for The Physcomitrella Genome Workshop. (Freiburg is located in the southwestern corner of Germany, close to the borders of France and Switzerland.) The moss Physcomitrella patens is the first bryophyte to have its entire genome sequenced. Basically it is the human genome project for mosses. Here you can check out the official publication of this research that appeared in Science this past December. At the workshop we will be learning how to use the genome databases and how best we can take advantage of this great resource.

It is going to be quite the whirl-wind trip but I am hoping that we will have a chance to see some of the local mosses. I think that it would be great to get outside and visit the Black Forest which surrounds the city. From the pictures that I have seen the mountains look beautiful. Unfortunately the weather prediction has it raining the entire time that we are there. I am crossing my fingers that they are wrong.

I am not taking my computer and with the schedule they have for us on posting on the moss blog will probably not fit in. I will have an update on how it all went when I return.

Auf Wiedersehen!

Moss and Alzeheimers Disease

I read this article entitled Moss Protein Plays Role In Alzheimer's Disease, Researchers Believe Science Daily. The title sounded really interesting but the article itself is not for the faint of mind. They use a lot of jargon and it has quite the round-about connection to . Maybe that is how most Science Daily articles are written? I don't read this publication very often. However if the intention is to communicate science to the public, I think that this article missed the target. Here is my outline/summary of this article.

Two groups of researchers at the University of Washington are working on components of cell communication channels. On group focuses on humans and the other group studies the moss Physcomitrella patens. They are now collaborating on a project to understand the similarities an differences between this pathway in their respective organisms. The main gene of interest in this pathway is presenilin (PS). Two different mutations can occur in this gene which result in early onset of Alzeheimer's disease in mammals. One of these mutations causes buildup of plaque on nerve cells in the brain.

Researchers were interested in what the PS gene is doing in mosses and if its function is similar to that in animals. They examined this by taking the gene from moss and inserting it into the animals that had a malfunctioning PS gene. They discovered that some of the function was returned. Thus these two genes have a similar function which can be found in genes that share an evolutionary history from a common ancestor.

They hope that by learning about the role of the PS gene in other functions throughout the body, of either mosses or animals, that they can better understand the effects of Alzeheimer's disease therapy.

Alzheimer's Disease, Researchers Believe. ScienceDaily. Retrieved March 9, 2008, from http://www.sciencedaily.com­ /releases/2008/02/080208153632.htm