Team:Cambridge-JIC/Marchantia

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<h2>Marchatia</h2>
 
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<p>Ginny suggested that we should have a page exposing Marchantia and extolling its virtues as a new chassis</p>
 
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yes she did!
 
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<h1> Welcome to Mar-Cam-tiamania Land!! </h1>
 
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Let us introduce to you to Marchantia Polymorpha (or Polly for short). <br>
 
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On this page you can find general information about our little plant, the reasons we love her and her path to being the new chassis for plant Synthetic Biology (and some trivia at the end).
 
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<h1>Introduction to <i>Marchantia polymorpha</i></h1>
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<p><i>Marchantia polymorpha</i> is a member of one of the most primitive divisions of land plants, the liverworts. It grows as flat sheets of tissue called thalli (a singular one is called a thallus), and once spotted is a common sight by the sides of ponds and streams, and in shaded gaps in masonry throughout the world. Each plant grows to be between two and ten centimetres across, and is quite unlike more familiar plants in a number of ways.</p>
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<h2> Who is Marchantia? </h2>
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Let's leave the botanical jargon and head to the gardens.<br>
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<p align="center"><img src="https://static.igem.org/mediawiki/2014/f/f8/Thalli%2C_phores_and_a_shoe.jpg" width = 800> </img> </p>
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Primitive plants are everywhere and together are called Byrophytes. <br>
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<p align="center">Some <i>Marchantia plants</i> near a shoe for scale
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<br>
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Byrophytes are divided into three lineages.<br>
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<p>Liverworts are defined by their simplicity. <i>Marchantia</i>, like other liverworts, has no vascular tissue and anchors itself not with true roots but with very long single cells called rhizoids, which become a matted array of filaments extending only ten or fifteen millimetres into the substrate. This simplicity is due to the retention of primitive characteristics evolved in early plants. One of these is the absence of flowers or seeds and the propagation of the plant in two old-fashioned ways.</p>
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In evolutionary order these are:
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<li>Marchantiaphyta or Liverworts (that's Poly!)</li>
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then came <li>Mosses (byrophyta)</li>
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and finally the <li>Hornworts or Anthocerotophyta.</li>
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</ul>
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<p>One of these ways is through the splash cups (or gemma cups) which pockmark the upper surface of the plant. Inside these cups grow tiny sproutlings of <i>Marchantia</i> called gemmae, with undeveloped rhizoids and thalli. They are halted from growing large inside their cups by the presence of a compound called lunularic acid in the space they inhabit, placed there by the tissue of the splash cup. When it rains, drops which fall into these cups rebound out and take these tiny gemmae with them, carrying them to the soil. Once on solid ground, they start to grow into a new individual.</p>
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<h2>Nature's strange ways: Role-Reversal Byrophytes and what makes them special </h2>
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<p align="center"><img src="https://static.igem.org/mediawiki/2014/1/1f/Gemma_Cup.jpg" width = 800> </img> </p>
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<p align="center">A gemma cup with gemmae visible inside
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Byrophytes are often referred to as 'Up-Side-Down' or 'Role-Reversal' plants.<br>
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Indeed, their life cycle is the opposite of most:<br>
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Humans, other organisms and plants spend their life as diploids. (two sets of chromosomes). Each individual however has a set of cells that undergo meiosis and form a haploid egg or sperm.<br>
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When the sperm and the egg come together, they form a haploid organism which grows.<br>
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Byrophytes live most of their life as haploids. They specialize a set of cells to become the ova and the sperm. When the haploid sperm reaches the haploid ove, they fuse, become diploid for a short time, and then undergo meiosis (split genome) to form two haploid plants!<br>
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Intrigued by this stangeness? Go to 'Marchantia's Life Cycle' to find out more.<br>
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They have no 'vasculature' or lignin and have regular morphology. But let's not underestimate them.
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Primitve does not mean fragile; quite the contrary they've had more time to optimize themselves.
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Poly can be found on all continents.
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<p><i>Marchantia</i>can reproduce sexually as well as through this ‘fragmentation’, and is in fact dioecious, meaning that an individual plant is either a male or a female. When induced by a shift in ambient light to far red, which signals that other plants are looming overhead, strange mushroom-like structures begin to sprout from the top of each plant. In males, these eventually take the form of a flat polygonal table, in females, the sprouts become archegonia, which look like miniature palm trees and when mature will bear eggs. </p>
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<p>The antheridia, as the male table-like structures are called, produce two-tailed sperm instead of the pollen you might expect. These are spread by rain to the waiting eggs of the archegonia , which they fertilise and induce to become hardy spores. These spores number in the thousands in each archegonium, which when twinned with the dispersal of gemma makes <i>Marchantia polymorpha</i> very prolific.</p>
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<p align="center"><img src="https://static.igem.org/mediawiki/2014/c/c3/Arch_and_anth.jpg" width = 800> </img> </p>
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<h1> The new Mar-vellous Chassis </h1>
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<p align="center">An archegonium, removed from a female plant (left) and an antheridium from a male plant (right)
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<h3>OpenPlant</h3>
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<br>
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Synthetic Biology conferences used to be like vegetable gardens (or zoos), with every researcher working on different organisms: a longer courgette here, a sweeter tomato there. Great to make some tasty dishes but a real halt for science. The animal field concentrated their forces from dogs and cats to Drosophila fly and the C.elegant worm, and the green handed people went for Arabidopsis or Tabacco.<br>
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Focusing on these few and simple organisms allowed science, techniques to be shared and developed by a community and core concepts, true for any higher organisms, emanated from this thrust.<br>
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Arabidopsis, is a great plant however some of its disadvantages, long life cycle, height, complex development is refraining progress. A wave is now building up as we speak behind Marchantia to develop it as the new tool for Synthetic Biologists and Plant Scientists. _ Watch this space_ (or even better: read on!)
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<p>The plants also have the ability to regenerate a whole new plant from a mere scrap of tissue, without the necessity of adding any hormones or other growth factors. Like in other primitive plants such as ferns, every cell contains a haploid genome except for a small amount of sexual tissue during the plant’s spore production stage.</p>
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<h4>The Beauty of Simplicity: Advantages of Marchy </h4>
 
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<h4>Collaborators and future for iGEM</h4>
 
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The Welcome Trust has recently given a huge push to the Marchantia Lovers. And these are sprouting from everywhere<br>
 
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For future iGEM groups who'd like to join this Marchantia Community, here are some of the people who are already in the stream (and would love to here from you!)
 
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For advice, plant strains to get started or just some info, contact:
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<p>These characteristics and the simple structure of <i>Marchantia</i>’s genome, which often contains just one gene where in higher plants (like <i>Arabidopsis thaliana</i>) are found complex clusters of genes of similar and overlapping functions, make it a fascinating plant to study. They also make it a chassis perfect for synthetic biology. </p>
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<li>Us!</li>
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<li>The Haseloff group in Cambridge- (home of the OpenPlant)</li>
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<li>Tokyo</li>
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<li>MIT</li>
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<li>JIC</li>
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<li>UEA??</li>
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<li>Online Community!</li>
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</ul>
 
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<h1> Marky Fun Facts & Trivia </h1>
 
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world records
 
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<h3>References</h3>
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Latest revision as of 01:39, 18 October 2014

Cambridge iGEM 2014


Introduction to Marchantia polymorpha

Marchantia polymorpha is a member of one of the most primitive divisions of land plants, the liverworts. It grows as flat sheets of tissue called thalli (a singular one is called a thallus), and once spotted is a common sight by the sides of ponds and streams, and in shaded gaps in masonry throughout the world. Each plant grows to be between two and ten centimetres across, and is quite unlike more familiar plants in a number of ways.

Some Marchantia plants near a shoe for scale

Liverworts are defined by their simplicity. Marchantia, like other liverworts, has no vascular tissue and anchors itself not with true roots but with very long single cells called rhizoids, which become a matted array of filaments extending only ten or fifteen millimetres into the substrate. This simplicity is due to the retention of primitive characteristics evolved in early plants. One of these is the absence of flowers or seeds and the propagation of the plant in two old-fashioned ways.

One of these ways is through the splash cups (or gemma cups) which pockmark the upper surface of the plant. Inside these cups grow tiny sproutlings of Marchantia called gemmae, with undeveloped rhizoids and thalli. They are halted from growing large inside their cups by the presence of a compound called lunularic acid in the space they inhabit, placed there by the tissue of the splash cup. When it rains, drops which fall into these cups rebound out and take these tiny gemmae with them, carrying them to the soil. Once on solid ground, they start to grow into a new individual.

A gemma cup with gemmae visible inside

Marchantiacan reproduce sexually as well as through this ‘fragmentation’, and is in fact dioecious, meaning that an individual plant is either a male or a female. When induced by a shift in ambient light to far red, which signals that other plants are looming overhead, strange mushroom-like structures begin to sprout from the top of each plant. In males, these eventually take the form of a flat polygonal table, in females, the sprouts become archegonia, which look like miniature palm trees and when mature will bear eggs.

The antheridia, as the male table-like structures are called, produce two-tailed sperm instead of the pollen you might expect. These are spread by rain to the waiting eggs of the archegonia , which they fertilise and induce to become hardy spores. These spores number in the thousands in each archegonium, which when twinned with the dispersal of gemma makes Marchantia polymorpha very prolific.

An archegonium, removed from a female plant (left) and an antheridium from a male plant (right)

The plants also have the ability to regenerate a whole new plant from a mere scrap of tissue, without the necessity of adding any hormones or other growth factors. Like in other primitive plants such as ferns, every cell contains a haploid genome except for a small amount of sexual tissue during the plant’s spore production stage.

These characteristics and the simple structure of Marchantia’s genome, which often contains just one gene where in higher plants (like Arabidopsis thaliana) are found complex clusters of genes of similar and overlapping functions, make it a fascinating plant to study. They also make it a chassis perfect for synthetic biology.