Abstract
Xylem vessels and tracheides consist of tracheary elements (TEs). We are analyzing mechanisms of TE differentiation using a culture system in which TE differentiation can be induced from newly isolated Zinnia mesophyll cells. We prepared ca. 9000 ESTs from Zinnia cells cultured for 48 and 60 hours, which include many differentiating TEs, and subjected them to microarray analysis. These experiments identified a clone encoding a homologous sequence of lipase genes. To date, little is known about lipid degradation during TE differentiation. We performed molecular biological analyses to reveal functions of the corresponding gene. In Arabidopsis genome, we identified an orthologous sequence of this gene and isolated its full-length cDNA. The expression of this gene occurred in TEs and other tissues such as root caps. Plants ectopically overexpressing this gene were produced for phenotype analysis. We will discuss the function of this gene based on these results.
