Moss Protonema and Lead

This week in Bryology Lab group I presented a scientific journal article about lead and mosses. It was a pretty interesting read. You may know that some heavy metals (ex. lead and mercury) are toxic. Think kids eating contaminated lead paint. It is bad for them and will make them sick. Well plants are the same way. If too many heavy metals get inside their cells they can damage the plant and make it sick.

One way that plants prevent heavy metals from entering their cells are by binding up the heavy metals before they make it inside. How do they do that you might ask? Well it is a pretty ingenious system. It has to do with their cell walls. Okay a little review. All cells are basically a sac (a bi-lipid membrane sac) filled with mainly water and other neat cell innards. Vertebrate animals give their cellular bodies structure with internal bones, insects have an tough exoskeleton that gives them shape, and plants have cell walls that help to keep them upright. Each of their cells is surrounded on all sides by these rigid cell walls that are connected together across the entire plant body. Without the cell walls plants would be a floppy mess.

Back to the connection with lead. The researchers determined that the moss plants, particularly at the protonema (filamentous) stage bound the lead to their cell walls so that it would not enter the cells. When placed in a lead bath they could even change the chemical composition of their cell walls to bind up (sequester) even more of the lead. This method does not keep all of the lead out of their cells but it is a good start. This phenomenon has been observed in the roots and pollen tubes of other plants. Boy plants are awesome!

Click on the citation below for a link to the paper.

Krzesłowska M., M. Lenartowska, E. J. Mellerowicz, S. Samardakiewicz and A. Woźny. 2009. Pectinous cell wall thickenings formation—A response of moss protonemata cells to lead. Environmental and Experimental Botany. 65:119-131.

Mosses in Malaysia

Well I sure had a whirl-wind adventure traveling around southeast asia for 2.5 weeks. The itenary was as follows. I flew from New York to Kuala Lumpur, Kuala Lumpur to northern Borneo (then back), Kuala Lumpur to Java (then back), I stayed put in Kuala Lumpur for a few days, and then home to Connecticut.

My favorite part of the trip was Northern Borneo. We were in Sabah, Malaysia near the town of Sandakan. We roomed at the Sepilok Jungle Resort, and I thought that it was a nice place to stay despite the poor review it was given in the most recent Lonely Planet Malaysia. We visited the Sepilok Orangutan Rehabilitation Center and the Rainforest Discovery Centre, both within walking distance of our lodging. With the rainy season upon us, we didn't get to explore aroung the rainforest nearly as much as I would have liked. Here are some of the mossy photos from the adventures.

All available surfaces were covered in mosses including tree trunks, fallen logs and hanging vines.

 

Here we have some mosses in the Calymperaceae. They are a very common family in the Pacific Tropics. Their identifying feature are the clusters of gemmae at the tips of the leaves.

 Some tiny critters like this ant were hiding among the mossy cover.

A few of the species that I saw had some tiny sporophytes rising above the leafy gametophytes.

The Holiday Rush

Apologies for the lack of posting recently. Unfortunately the blogging silence may continue for a little longer. This break has been full of travels for me.

I went back to Ohio for a week to visit my family. Then a week back in Connecticut. Next I was off to national meeting of the Society for Integrative and Comparative Biology & American Microscopical Society in Seattle, Washington. I presented some of the preliminary results from my dissertation research in an oral presentation. Then a week back in Connecticut. Now I am off on a vacation-adventure to visit a friend in Malaysia who is working on her dissertation research there. I will be visiting both peninsular Malaysia in Kuala Lumpur and the island of Borneo, which includes parts of Malaysia and Indonesia.

I leave this upcoming Monday so my excitement and anxiety for this adventure are mounting! We will be visiting a couple of National Parks and the moss diversity should be spectacular. I won't be doing any collecting but I do hope to capture the beauty in as many photos as I can fit on my camera!

I will have some internet access but it is only a 2.5 week trip, so I am not sure how much blogging I will do on the road. I will most definitely share all the mossy wonder from the trip with you all when I return!  So stay tuned, I will be back in the country on Feb 4th with adventure tales to tell.

The Reski Laboratory on Twitter

I just discovered that the Reski Laboratory is on twitter. They study the moss Physcomitrella patens at the University of Freiburg in Germany.

I am tossing around the idea of using twitter when I don't have time for longer blog postings. I signed up for an account to check it out and you can link to it here (Not that I have twittered anything yet). I am trying to wrap my mind around how I would use it and how it might add to the blogging. We shall see. It is another experiment!

Feel free to leave a comment about this new experiment to use twitter in association with this blog for communicating science and all that is mossy to a broader audience.

What do you think?
Yes, twitter is great and it will add to the blog.
No, twitter is evil and focusing on more blog posts would be time better spent.

Berry Go Round #22

The latest edition of the plant carnival Berry Go Round has been posted at Seeds Aside. One of my posts from this past month has been included in the lineup! Link through to checkout all the interesting botanical topics from November 2009. 


P.S. Be sure to note that the banner heading at Seeds Aside features some great looking plants.

For more about blog carnivals and my posts about the earlier editions of Berry Go Round, click here.

Some Birds Like the Moss

One of the ornithologists in my department forwarded along this article about Australian woodland bird conservation that mentions mosses.

R.M. Montague-Drake, D.B. Lindenmayer and R.B. Cunningham. 2009. Factors affecting site occupancy by woodland bird species of conservation concern. Biological Conservation Volume 142, Issue 12, Pages 2896-2903.

They focused on  patches of woodland and studied which aspects of the woodland affect the presence of 13 different bird species. One of the factors they measured was the % of the ground or rocks that was covered by mosses and lichens.

They found that 5 of the bird species were more likely to be found in woodlands with high percentages of moss and lichen cover. They lichen-ed them! (Teaching Bryology and Lichenology there were so many bad lichen jokes during the laboratory period, but I still found them totally funny.) 

The authors mention that often in other studies they do not distinguish between 'bare ground' and 'moss and lichen covered'. I would have to agree that there is a big difference between the two. Moss layers hold moisture, prevent soil erosion, and serve as housing for invertebrates and other small critters.

It is great to read that some species of birds thoroughly appreciate their moss and lichen neighbors!

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?

Darwin's not that Cool

Charles Darwin's work On the Origin of Species is celebrating its 15oth birthday/publication-day today. A lot of news outlets are talking about the influence of this book on our scientific thinking about evolution. Checkout NPR, BBC and NYTimes for more info. I really don't have much more to add to that information-wise about Darwin. I've read parts of On the Origin and as a thinker he was way ahead of his time with some really great thoughts.

But honestly, just between you, me, and the blogosphere he is not my favorite historic (aka. dead) scientist. Beating him out by a long shot is Wilhelm Hofmeister. Ok, so you have probably never heard of Hofmeister. His position as an unknown underdog is one of the reasons I like him and his scientific discoveries. I study mosses. I tend to like the underdogs and migrate toward championing them.

Hofmeister's major discovery was to observe and outline the alternation of generations in many different kinds of plants from bryophytes to flowering plants. Basically he figured out how different parts of the plant life cycle go from gametophyte to sporophyte and then back again. He was the first scientist to figure out and discribe this important plant phenomenon.

He only had a basic education equivelent to trade school through age 15 and was entirely a self-taught botanist. Also he was very near-sighted. So much so that he sometimes did not recognize people walking down the street. However this sort of turned his eyes into magnifying lenses enabling him to see tiny plant parts and mini mosses.

Check out this scientific journal article to read more about Hofmeister and his scientific contributions.
The Genius of Wilhelm Hofmeister: The Origin of Causal-Analytical Research in Plant Development. Donald R. Kaplan and Todd J. Cooke. American Journal of Botany, Vol. 83, No. 12 (Dec., 1996), pp. 1647-1660.

Hofmeister also has a well-referenced wiki entry that appears to be accurate considering its wiki-ness.

A Mossy Embrace

A fellow graduate student forwarded along this link to a BBC news page reporting on the results of a photo competition. The photo that won the student category is a pair of moss sporophytes sticking out of the snow. (#13 in the series.) The photo is entitled Embrace. It is a great picture with nice imaginative imagery in the quote from the photographer. Some of the terms that she uses in the caption are not entirely bryologically accurate or maybe they are just not the terms that I would use. However I am trying to not be such a scientist, so I am not going to critique them here. I encourage you to suspend reality and any terminology hangups that you might have and to enjoy the beauty of these snowy sporophytes.

An additional news source that reported on the competition is the Guardian News. Click here for the link to another version of the moss image and its associated caption. (Photo #7)

(We are reading the book Don't Be Such a Scientist: Talking Substance in an Age of Style in the Science Communication seminar I am taking. Thus I am trying to relax into my science communication and not be so picky about terms especially when the above photo is art. We shall see how it works.)

Moving and Mossing

A couple of weekends ago I helped one of my grad student pals move into his new house. I arrived a little early and explored the moss diversity on the property. There was an old well behind the house that was covered by mosses. It has a nice bit of species diversity. I have included some of the photos below.

I was on a photo spree and did not do any collecting to identify the specific species. I think that I will have to visit again to do a more through survey.

Blogging Pause

October has been a busy month for me with a trip to Virginia and juggling a number of projects here in the lab. All the balls are still in the air and I am feeling pretty good about that. However as you can see the blogging has suffered, with my last post being over a month ago. I have been amassing ideas for new posts over the month and am planning to write some of those during the upcoming weekend.

For now...

- The latest edition of the plant blog carnival Berry Go Round is up at Beetles In The Bush (#21) for your perusal. My favorite article of the bunch was the post at The Natural Capital about wild grapes. It is a well written post with a good hook at the beginning. Then great facts on identifying wild grapes and tips on avoiding other fruiting plants that you might mistake for grapes.

- The trip to Virginia was to see a friend and former Grad Student from my department who now lives in Virginia. I left the shutter-bugging to the other gals so I don't have any pictures of our outing to the Shenandoah National Park. It was a great autumn day and there were tons of mosses to be seen! If you would like to see some photos and the tale of hiking adventures with four botanists you can check out Em's blog post here.

Berry Go Round #20

The latest edition of the plant carnival Berry Go Round has been posted at Further Thoughts. Stop by to check out this month's plant posts from the blogosphere!

For more about blog carnivals and my posts about the earlier editions of Berry Go Round, click here.