What Plants Can Tell Us About Gene Suppression
October 15, 2008
In this segment, Lehman Professor Dominick Basile tells us about his research in the plant sciences.
7 Minutes 1 Second
In "World of Plants," Lehman faculty share their research in the plant sciences, discussing some of the health benefits found in plants and, in some cases, what plants tell us about humans.
This is Kelly Worby, a nursing major at Lehman College.
In this segment, Lehman Professor Dominick Basile tells us about his research in the plant sciences. Working with a plant that produces an anti-malarial drug, he learned more about gene suppression. He theorizes that interfering with the normal patterns of plant development might uncover how developmental capabilities in human beings could likewise be changed.
Most of my work is around this basic concept of suppression of place-- things are suppressed at a given time at a given place during the course of development of any individual. And so most of it has been done with more thought, with the form of plants. But some years ago, maybe 15 or 20 years ago, a colleague of mine who was a biochemist wanted to use my tissue cult-- my-- my ability to do work with plant tissues. To see if I could use tissue from this plant that makes an anti-malarial compound to produce this anti-malarial compound.
Artemisia-- this plant that makes this powerful anti-malarial drug-- only grows in temperate climates. But malaria is a drug-- a disease of-- the tropics and subtropics. And so you can't grow the plant there. You have to grow 'em here, extract it, get the drug here, and bring it down to Africa, South America, any tropical area.
According to the literature, these plants' only make this compound in little-- glandular cells on the surface of the plant. So they're special little glandular hairs on the surface plant. If they have a mutant and the plant doesn't have these glandular hairs, it can't make that compound, according to the literature.
But in the course of doing experiments just with the tissue, had no leaves and had no glandular hairs, had nothing. Just masses of cells. But changing the conditions under which the cells were cultured, we got the cells to make this Artemisia, which is still the most important, useful anti-malarial drug available.
I thought maybe if we could get-- develop a technology which could produce large amounts of this anti-malarial drug in tissue culture-- you know, large-scale tissue culture. You could set up these laboratories down in countries where they need it-- and produce it. And I found that not only did the tissue make the drug, but it released the drug into the-- growing it in a liquid medium.
So the cells just dumped the drug out into the culture medium. And so it was much more easily extracted than you would from cutting down the plants and using strong, organic solvents. And so this is really another manifestation of this concept of suppression or I should say de-suppression. All cells should be able-- any cell should be able to make Artemisia. And if some cells of the plant can make it, then any cells can, 'cause they all have exactly the same genetic makeup.
By interfering with certain aspects of chemistry-- metabolic pathways-- I could cause things that were normally suppressed, like where a leaf forms or how large a leaf got or where a branch formed and how large it got. Could be expressed in the normal course of development. If you didn't do these experiments.
So I started doing experiments, trying to modify the culture medium-- the traditional media in which they were growing-- to see if I could change their pattern of development. And in the course of doing those experiments I introduced different compounds into the-- and one thing I entered, introduced to the medium, changed the pattern-- not the pattern of vision of the cells of the leaves, changed the whole plants. And so it had two rows of leaves, and the leaves are one shape. All over the world where this plant is collected it looks exactly the same. Anybody can identify it that knows the plant. In-- under these set of conditions, it changed the leaves-- changed the plant so much that instead of two rows of leaves, it had three rows of leaves. The leaves were a different shape than the plant's supposed to be.
Now this was not a mutation. It was temporary. Only occurred while the compound I added to the culture medium remained in the culture medium at a certain level. It was used up during the course of development. It used up-- as soon as it was used up, the plant went back to looking like it's supposed to look.
Here you had potential in different parts of its body to form a leaf, to initiate a branch. And all those potentials, those populations of cells, were there and didn't get expressed unless I interfered with this particular kind of a protein in the plant.
The central thing that interests me is that all the cells of a plant or all the cells of a person's body have the same genetic information. Yet certain parts of the plants or certain parts of your body make one compound, other parts make another compound. So that must mean that certain genetic or certain capabilities-- developmental capabilities-- are present in all the cells-- of a plant's body or an animal's body. But only some of the capabilities are expressed at a given time in a given place. And the ones that aren't expressed are suppressed.
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