“Differential cell growth in Arabidopsis fruit and its relation to FUL”

Project Summary:

The fruit is a highly-specialized plant organ and its development is crucial for plant reproduction. Fruits of Arabidopsis thaliana, which are typical of the more than 3000 species of Brassicaceae, including the agronomically important crop canola, is an ideal system to study cell growth and cell patterning. We use the fruit valve as the model system to study cellular development and attempt to investigate the mechanism regulating valve development. We found that the sizes of cells on the surface of fruit valves are uniform before fertilization but then become non-uniform along the apical-basal axis post-fertilization. The cells in the middle region are longer compared to the cells at the top and bottom, and imaging of the valve over the course of maturation shows that the middle part has more cellular growth compared to other regions. Also, the cell size pattern correlates to expression of the FRUITFULL (FUL) gene along the same axis, indicating the linkage between FUL and valve cellular growth. Confocal imaging of FUL-related mutants shows altered cell sizes. We also performed flow cytometry experiments on cell samples from wild-type, FUL overexpression line, and ful mutants and the data indicates that FUL is not affecting cell growth through regulating endorepduplication. In conclusion, we find that the middle parts of the fruit valves have more growth compared to other regions, leading to non-uniform cell size distribution on the valve surface. FUL is involved in regulating cellular growth, even though not through affecting endoreduplication. FUL level is positively correlated with valve cell sizes.

My Experience:

Before interning at BTI, I knew that I wanted to be a biologist, and to have a career in research, but I really had not considered researching plants. During this internship, however, I realized that some of the biggest problems my generation will have to contend with will center around food, namely making our crops more efficient in the face of climate change. My overall appreciation for and understanding of plant science has expanded immensely during this internship.

Furthermore, I feel I have grown as a researcher in several respects. I have gained a deeper understanding of experimental design, and the process of carefully planning each experiment based upon the results of the previous one. I am glad to have broadened my laboratory skill set this summer in learning to use a confocal microscope and various other lab machines and software.