Abstract
Plant cell walls contribute to the development and the functional specialization of cell types. It is highly organized composite of many different polysaccharides, lignins and cell wall proteins. Although the structural framework of the cell wall is mainly polysaccharides, structural proteins may also form networks in the wall. One of the structural proteins: glycine-rich protein (GRP) is difficult to extract and may become cross-linked into the cell wall. Cell walls of many kinds of plant species contain GRP. However, the function of GRP is not well known. When we examined the expression pattern of all rice GRP by database analysis, few genes have been expressed in rice. Then, we focused on a highly expressed gene, OsGRP2, and analyzed the expression pattern and the mutant phenotypes. In the vegetative stage, no obvious morphological difference could be observed between osgrp2 and wild-type. However, during the reproductive stage, the tapetum did not form normally in osgrp2 mutants. These results suggest that OsGRP2 might be important for the formation of tapetum and consequently involved in the pollen development.
