Two cytosolic cyclophilin genes of Arabidopsis thaliana differently regulated in temporal- and organ-specific expression

We have previously isolated two closely related genes (ATCYP1 and ATCYP2) e ach encoding a cytosolic cyclophilin of Arabidopsis thaliana. Here we teste d expression patterns of these two genes by Northern analysis and by histoc hemical analysis with transgenic plants carrying the promoter: beta-glucuro nidase (GUS) fusion. The results showed that ATCYP1 is predominantly transc ribed in vascular tissue and flowers, but ATCYP2 is at higher levels in you nger leaves. The different expression patterns seemed to be conferred by th e quite different promoter structures carrying various cis elements. Our fi nding suggests that the two cyclophilins have different roles in Arabidopsi s thaliana cells.