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Submitted to: Leafy Spurge News
Publication Type: Other Publication Acceptance Date: 11/1/2000 Publication Date: 2/1/2001 Citation: Horvath, D.P. 2001. Believe it or not. Leafy Spurge News. 23(1):6. Interpretive Summary: Believe it or Not What makes leafy spurge different from most other plants? Apparently not much (so long as you overlook the latex, root buds, and a few other things that annoy cows and people) according to Dr. Dave Horvath with the USDA-ARS Plant Science Research unit in Fargo. Recently his lab undertook an experiment designed to understand how similar leafy spurge is to Arabidopsis thaliana. Leafy spurge is a perennial weed in the "Euphorbia" family, while Arabidopsis is a simple annual weed in the "mustard" family. Because of its simplicity, Arabidopsis is being used as a model to study how plants grow and respond to their environment. Think of it as kind of the fruit fly of the plant kingdom. Because it has been chosen as a model plant, a large amount of money and time has been spent on gathering information on the genetics and physiology of this small weed. In fact, it is very likely that the entire genome of this plant will be sequenced by the end of the summer. Because there are a lot of tools and tricks that have been developed to study growth and development in Arabidopsis, we thought it might be helpful to see if we could use some of them to help us understanding how the growth of leafy spurge root buds is controlled. One of the more useful techniques that has been developed is known as micro-array technology. Micro-arrays are made by spotting a very small amount of a specific gene on a microscope slide. Because the spots are so small, one can easily place over 20,000 different genes on a single slide (note there are probably only 20,000 to 30,000 different genes in most plants). Once such slides (or "chips" as they are commonly called) are made, one can use them to study what is happening in the plant during a specific change in growth or after exposure to stress. For a more detailed explanation of how micro-arrays help us look at what genes are turned on and off, see the article by Dr. Wun Chao in this issue of Leafy Spurge News. We do not yet have enough genes cloned from leafy spurge to make a leafy spurge chip. Consequently, we wanted to see if we could use Arabidopsis chips to study growth and development of leafy spurge. It was hoped that, since leafy spurge and Arabidopsis are both plants, the genes they contain would be similar enough that some of the cDNAs from the leafy spurge genes would find their Arabidopsis counterpart on the chip. Consequently, Dr. Horvath traveled to Michigan State University where they routinely do micro-array experiments with Arabidopsis chips. To test the system, Dr. Horvath compared young growing leaves of leafy spurge plants to mature leaves (both of which are much easier to collect than growing vs. non-growing root buds) and looked to see if we could use the Arabidopsis genes on the chip to see specific differences in these two samples. The experiment was a surprising success. Leafy spurge cDNAs stuck to over 80% of the Arabidopsis genes. It was clear that we could see some genes that were turned on in the young leaves and off in the old ones (and visa-versa) on the Arabidopsis chips. Although there are probably four to eight thousand genes that are too different to detect, it looks like there is enough similarity between Arabidopsis and leafy spurge to use this powerful tool to study gene expression in leafy spurge and possibly other weeds and crops as well. Use of this technique will undoubtedly lead to the identification of genes involved in stress responses and growth and development. Once such genes are identified, we can begin to study how they are turned on and off. If we can learn this, we should be able to find ways to turn these genes on or off and develop new ways to control the growth of leafy spurge. Perhaps we will someday be able to cause the root buds to grow in late fall or prevent their growth in the spring or turn off the genes that help protect spurge f Technical Abstract: What makes leafy spurge different from most other plants? Apparently not much (so long as you overlook the latex, root buds, and a few other things that annoy cows and people) according to Dr. Dave Horvath with the USDA-ARS Plant Science Research unit in Fargo. Recently his lab undertook an experiment designed to understand how similar leafy spurge is to Arabidopsis thaliana. Leafy spurge is a perennial weed in the "Euphorbia" family, while Arabidopsis is a simple annual weed in the "mustard" family. Because of its simplicity, Arabidopsis is being used as a model to study how plants grow and respond to their environment. Think of it as kind of the fruit fly of the plant kingdom. Because it has been chosen as a model plant, a large amount of money and time has been spent on gathering information on the genetics and physiology of this small weed. In fact, it is very likely that the entire genome of this plant will be sequenced by the end of the summer. Because there are a lot of tools and tricks that have been developed to study growth and development in Arabidopsis, we thought it might be helpful to see if we could use some of them to help us understanding how the growth of leafy spurge root buds is controlled. One of the more useful techniques that has been developed is known as micro-array technology. Micro-arrays are made by spotting a very small amount of a specific gene on a microscope slide. Because the spots are so small, one can easily place over 20,000 different genes on a single slide (note there are probably only 20,000 to 30,000 different genes in most plants). |
