Many genetic programs are aiming at modifying crops for better processing properties of the lignocellulosic biomass in biorefinery. However, any modification of cell wall might trigger plant cell wall integrity signaling, which potentially can interfere with growth or productivity. To be able to modify crops, it is therefore essential to understand their cell wall integrity sensing pathway. We are offering a MSc project at the Umeå Plant Science Centre within the Wood Matrix Polysaccharides group of Prof. Mellerowicz investigating the secondary wall signalling pathway. The project is incorporated into a thesis work directed by the PhD student Félix Barbut.
We use the model plant Arabidopsis thaliana. The project consists of three different parts, which will be run in parallel.
In the first part of the project you will be working with transgenic plants which have defective secondary cell walls. The goal of this part of the project is to define easy-scorable phenotypes and reproducible phenotypes of these plants. These phenotypes may be include defects in seedling growth on the agar plates, altered resistance to abiotic stresses, like salt and osmotic stress, or altered morphology of soil-grown plants.
In the second part of the project, you will study different mutants selected based on previous expression network analyses and literature on cell wall integrity. We will test if any of these mutants lost the ability to react to secondary cell wall defect. The phenotypes of the mutants will be determined similar to the transgenic plants with cell wall defects. To test, our hypothesis, these mutants will be pollinated with the pollen of transgenic plants having defective secondary walls.
In the third part of the project, you will select transgenic plants in the mutant background from the progeny of pollinated plants. Such selected lines will be then compared with the lines in the WT background to confirm that the mutated genes are required for the phenotypic reaction to the altered secondary wall.
The selected student will therefore be responsible of the following studies:
- 1) Preparing agar plates and sowing seeds in vitro. The transgenic lines will then be grown for 10 days on agar plate with or without osmotic stress.
- 2) Measuring the length of the root. This is done on a high resolution photograph via the ImageJ tool which is very easy to use but it requires a certain precision. The results obtained will be tabulated in excel sheets and analysed using a statistical approach.
- 3) Following the growth of plants in a greenhouse accredited to use transgenic material. From seed to harvest, the student will be familiarized with the greenhouse safety regulations when sowing, watering, pruning plants and harvesting seeds.
- 4) Performing crosses between different transgenic plants and the mutants. This mission is essential for the continuity of the study and requires being meticulous and calm for a good success. The training will be provided.
- 5) Genotyping the generated progenies to confirm the success of the crosses using PCR.
We hope to provide a good practical educational for the student we expect the student take care to gather reliable data essential for our work. We would love to have the opportunity to discuss this project further in an interview via Zoom.
Supervisor: Ewa Mellerowitz, Félix Barbut, Dept of Forest Genetics and Plant Physiology, SLU.