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Red Commissar
24th September 2013, 00:29
Probably not too interesting to some, but personally it's cool to me in biology that after so many decades of a fairly established cell system, we are still finding some new features...

http://blogs.scientificamerican.com/food-matters/2013/09/20/tannosomes-and-the-trickle-around-effect/


Last week, when French researchers unveiled a newly discovered plant organelle related to wine and tea, I waited for frenetic coverage. And waited. Only a few obscure wine websites covered the news.

When I contacted the study co-author, Jean-Marc Brillouet of the French National Institute for Agricultural Research (INRA), he immediately put me in touch with another team member who could speak with me on short notice (Brillouets schedule was booked).

It was the last frontier in plant biology, co-author Charles Romieu, also of INRA, told me excitedly over the phone.

After untold hours in the lab experimenting with different transmission electron microscopy (TEM) imaging methods, the team found a new organelle inside the plant cell: the tannosome. Its responsible for churning out tannins, the naturally occurring molecules belonging to the polyphenols class of organic chemicals. If youve ever sipped wine, tasted tea, or paddled around in the tannic acid waters of the Florida Everglades, then you know what tannins are: bitter compounds. These important molecules are found in tree bark, vascular plant leaves and not-yet-ripe fruit. Tannins are natures way of saying, Hey, back off to would-be predators. They also offer UV protection.

We were very happy because nobody knew exactly where the tannin occurred. It was really a mystery, Romieu said.

Before the discovery of this separate organelle, at least one previous study hinted that tannins were perhaps in the tonoplast.

But it turns out tannins have their own organelle factory. The tannosome helps cells synthesize highly toxic and insoluble compounds.

People have been trying to figure this out since the 1960s, said Ian Burbulis, a researcher in biochemistry and molecular genetics at the University of Virginias School of Medicine. His voice, too, was edged with enthusiasm.

Skyhilist
24th September 2013, 02:04
This is pretty awesome.

Another fun fact about tannin: it's what makes redwood trees so resistant to insects, fungi, and even fires. It also gives the redwood trees their beautiful deep red color.

Anyways, pretty groundbreaking discovery.

Red Commissar
25th September 2013, 20:50
This is pretty awesome.

Another fun fact about tannin: it's what makes redwood trees so resistant to insects, fungi, and even fires. It also gives the redwood trees their beautiful deep red color.

Anyways, pretty groundbreaking discovery.

What's interesting to me is that this is derived from the chloroplast. The chloroplast, like the mitochondria, is believed to have been a prokaryote that entered into a symbiotic relationship (http://en.wikipedia.org/wiki/Endosymbiotic_theory) with the ancestor of eukaryotic organisms to the point that they were eventually integrated into the emerging eukaryotic organism.

So my question would be this- was this a benefit that the ancestral chloroplast imparted to the cell? Or if it was something that arose later when it was integrated?

Skyhilist
25th September 2013, 20:57
That's a good question -- seeing as they've just discovered this I imagine that might take some time to answer.

Or maybe there is an implied answer that the botany world is aware of, which would just go to show that botany is not my best scientific field lol

Red Commissar
25th September 2013, 21:15
I don't have much interest in botany either truth be told, but it is a field where we do get a lot of initial information from. A lot of our tests on diseases, carcinogens, DNA (and other genetic-related stuff), the way cells work and what not started from botany because they are easier to observe and manipulate over multiple generations, and made their way into other fields (though advances in microbiology have also provided a different avenue for this). For example, a lot of what we know about epigenetics- changes that don't originate in a mendelian manner- originated from botany research.

One concrete example I can bring up is that of transposons, which are elements in DNA which move around within the genome in a random form ("jumping genes" as they are referred to sometimes), and can be detrimental. They were originally found in plant cells, and it was originally assumed that they were a weird feature of plant cells until they were found in other eukaryotes and prokaryotes too.