Oded Shoseyov

Arabidopsis thaliana endo-1,4-

Summary Transgenic aspen plants were transformed with a bacterial s-glucuronidase gene ( uidA ) under the control of the Arabidopsis thaliana elongation-specific endo-1,4-s-glucanase ( cel 1 ) promoter. Transformed plants exhibited a high level of s-glucuronidase (GUS) activity in young, fast-growing tissues. Unlike the cauliflower mosaique virus 35S promoter, the expression pattern of uidA in the shoots and leaves was clear-cut and highly controlled by cel 1 promoter. GUS-staining in the leaves mirrored the pattern of expanding cells in the organ. These results further substantiate the link between cel 1 expression and plant cell elongation. Moreover, our results suggest that the cel 1 promoter may be useful in the genetic engineering of forest trees and possibly other plants when gene expression is desired only in fast growing tissues.