Abstract
The plant cell wall is constructed outside the plasma membrane by many kinds of proteins, most of which are encoded by multi-gene families. Although many cell-wall-related gene families have been identified, little is known about their expression profiles. By means of the microarray technology and the quantitative real-time RT-PCR procedures, we have analyzed expression patterns of individual members of the cell-wall-related gene families in Arabidopsis. The results reveal that each member of a gene family exhibits its own expression profile in terms of tissue specificity and responses to hormonal signals, with some members exhibiting similar expression patterns. Phylogenetic studies suggested that most of the gene-pairs, which had been generated by gene duplication, show similar expression patterns and share common sequences in their promoter regions. By focussing on root-specific members of xyloglucan endotransglucosylase / hydrolase (XTH) gene family, we discuss evolutionary implication of diversification and conservation of the expression patterns.
