Tissue-specific silencing of a transgene in rice

摘要

In a transgenic rice line, a β-glucuronidase reporter gene under the control of the rice tungro bacilliform virus promoter became gradually methylated, and gene activity was lost concomitantly. Methylation was observed only in the homozygous offspring and was initially restricted to the promoter region and accompanied by loss of expression in the vascular bundle tissue only. This expres- sion pattern was similar to that of a promoter with a deletion of a vascular bundle expression element. The gene activity could be reestablished by treatment with 5-azacytidine.