Today in Cool Things I Found to Show My BIO 101 Students

This is the Rhizanthella gardneri! It is an orchid that lives entirely underground. It was first discovered in 1928 and its home is Western Australia.

220px-Rhizanthella_gardneri_—_Fred_Hort

It is one of the only known plants to exist entirely underground and it’s also critically endangered. Only 50 individual plants were left in the wild in 2011. It is a parasitic plant, which means it gets the majority of its nutrients from other plants. In 2010, scientists at the University of West Australia discovered gardneri gets its nutrients from fungi that live on the root of the broom bush, a woody Australian shrub.

light-reaction1

The most interesting aspect of these plants is that they still contain chloroplasts! Chloroplasts carry out photosynthesis. Photosynthesis is the process of generating ATP using the sun’s rays, water and O2. Think of them as the plant cell’s version of mitochondria. In the picture above you can see an overview of the entire photosynthesis process. The gardneri orchid would not need to carry out the light dependent reactions on the left because…

orchid lives UNDER THE GROUND WHERE THERE’S NO SUN??

So of course scientists took a closer look at these unnecessary chloroplasts. Fun thing about chloroplasts,just like mitochondria, they have their own special DNA, unique to the chloroplast and different from the cell’s DNA in the nucleus. And it turns out that gardneri chloroplasts’ DNA are missing 70% of their DNA compared to equivalent chloroplasts in above ground plants. The plant has evolved so that only genes that are useful to being a parasitic plant are left. These genes create 4 different proteins. The nice thing is that scientists have always wanted to know what the other chloroplast genes that are not involved in photosynthesis actually *do* and now they have the perfect opportunity to do so. (It was too hard to accomplish this using every day plants that had the full set of chloroplast DNA.)

The researchers also think this discovery could help them to understand gene loss in other parasites.

I could see this being important because plant life on other planets may take this form.

Sources;

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