Cloning And Functional Analysis Of Promoter Specially Expressed In Trichome In Arabidopsis

Trichomes are specialized epidermal cells, which are normally present on the leaves, stems, and sepals of Arabidopsis. They are thought to provide a first line of defence against pests and pathogens, so the cloning and analysis of trichome-specific-promoter is of significance.Described here is the cloning and characterization of a new trichome-specific-promoter in Arabidopsis.By DDRT(differential display reverse transcription)-PCR and reverse northern, a 280bp sequence is acquired from the epidermal in Viciafaba, which is specially expressed in the epidermal. Then using RACE, we abtain a 3.0 kb gene segment including the 3'end full sequence and the 5'end partial sequence of the 280bp segment. The blast analysis of the 3.0kb segment indicate that it is similar to translational activator and has more than 80% homology to two genes in Arabidopsis and Oryza saliva respectively.We clone a 1.3kb promoter sequence of the homologous gene in Arabidopsis by PCR. This promoter is shown to direct the specific expression of the reporter gene,B-glucuronidase(GUS), in trichomes of Arabidopsis. Promoter deletion analysis reveal that the region from -300 - -1 bp is sufficient to direct trichome-specific expression.This promoter may provide efficient bioengineering to enhance pest and pathogen resistance, and is of theoretical significance on the trichome molecular system.