Comparing genotype and phenotype in wax-less Barley mutant

Abstract

Wax production is essential for the survivability of Barley (Hordeum vulgare) plants. They use it to fend off bacteria, viruses and helps rinse the cuticular surface from dirt. Much research has been done regarding the genetic regulation and the cer-cqu genes are proven to account for the biosynthesis of wax. A point mutation has been induced within the cer-u region which gives rise to waxless plant offspring. By using the point mutation as a landmark for primer recognition when running polymerase chain reactions it is possible to verify that the point mutation disrupts mechanisms of the protein the cer-cqu genes code for. The results can then be visualized by gel electrophoresis. Our results show that the mutation in the cer-u region renders wax production impossible and that the point mutation is present in all waxless population plants. By learning how to control the production of wax one can use that information to optimize the plants growing, one example is constructing more drought-tolerant plants.

Popular Abstract

Comparing the looks and personality of Barley plants

If you ever drove on the country side surrounded by fields of Barley you might enjoy the way it looks, maybe it has a cozy feeling to it or simply you enjoy being someplace else than where you are used to be. But it is not only enjoyable for you, it is actually enjoyable for the Barley plants aswell. One of the reasons that make it so enjoyable is the fact that Barley plants produce wax on their outer surfaces. This is much like our immune system, it protects the plants against virus, bacterial and fungi infections. But there is also second function of the wax, it helps the plant to preserve water inside the cells. One could say that having wax is necessary for the plants to survive in the nature. But, the wax is only found on the outside of the plant, what about the inside?

No, there is no wax on the inside of the plant, however, the production of wax is entirely possible because of what is inside the cell, the DNA. Barley cells have a cluster of genes we call the cer-cqu genes. These genes code for a large enzyme that helps produce a specific type of alcohol (probably not drinkable) and diketones (which is another type of carbon based molecule). These molecules make up for more than fifty percent of the wax, and as you can see, these genes are important to inherit from your parents.

But what if the plants don’t inherit the genes from their parents? This is the subject we have been touching. By treating Barley seeds with X-ray it will induce mutations to form in the genes, and if the mutation is within the cer-cqu region, the plant will not be able to produce wax, and this is inheritable. If this plant is crossed with a functional wax-producing plant the offspring will have a chance (25% actually) to inherit the mutation from it’s parent and thus also become waxless.

So, in a green house somewhere in Lund there are 636 of these plants, that either has a wax-less outside or wax on it. By collecting a leaf filled with cells and thereby DNA, we can amplify or clone the DNA using the machinery that cells use in normal instances. Then we can run these samples through a gel, which resembles a maze, and depending on the sizes of the cloned DNA fragments they will travel different lengths, and this we can read by detecting fluorescence from the samples.

So far, we have found one mutation that is present in all the waxless plants and absent in all the wildtype plants. It is a mutation within the cer-u region which has changed an adenosine base to a cytosine base.

Supervisor: Mats Hansson
Degree Project, 15 credits, 2015
Department of Biology, Lund University

• author: Persson, Max
• supervisor: Mats Hansson
• organization: Degree Projects in Molecular Biology
• course: MOBK01 20152
• year: 2016
• type: M2 - Bachelor Degree
• subject: Biology and Life Sciences
• language: English
• id: 8839797
• date added to LUP: 2016-03-09 16:18:18
• date last changed: 2016-03-09 16:18:18