Activity of constitutive promoters in various species from the Liliaceae.

In this paper we first review literature on the performance of various promoters in monocotyledonous species. In general, promoters isolated from monocots show a higher activity in monocot species. Moreover, the presence of an intron between the promoter and reporter gene increases transcription levels. We used the same approach to study gene expression in Liliaceae. The activities of the CaMV 35S, maize Adh1-based pEmu, rice Act1 and maize Ubi promoters, coupled to the beta-glucuronidase (gus) reporter gene, were evaluated for transient gene expression upon particle bombardment of tissues of tobacco, rice, tulip, lily and leek. Although monocot promoters performed very well in rice tissues, the results of this study show that this cannot be generalized for other monocot species. The transcription inducing effects of monocot promoters were less pronounced or even absent in tissues of Liliaceae, while the presence of an intron between promoter and gus gene reduced promoter activity.