We hope to understand how this change is brought about by isolating the genes involved and studying their functions. Many of these genes will be similar to genes involved during shape change in other plant cells, but at the moment we know almost nothing about any of these. By using root hairs as a model, I hope to get insights into mechanisms governing cell shape in all plant cells. Shape change is important because many specialised cell types, including root hairs, depend partly upon their shape in order to function. Shape changes in plant cells are very different from those in animal cells.
Animal cells are soft and flexible and can change shape reversibly.
In plant cells, changes in cell shape require permanent changes in the shape of the rigid wall surrounding the cell. Root hairs are tip-growing. In developing root hairs, new cell wall is produced by tip growth, a mechanism that is used in several other important cellular systems including pollen tubes, fungal hyphae and Rhizobium -induced infection threads. It has proved difficult to analyse the genetics and molecular biology of tip growth in these other situations. Root hairs of Arabidopsis thaliana are amenable to powerful and rapid molecular genetics.