Transgenic rose lines harboring an antimicrobial protein gene, Ace-AMP1, demonstrate enhanced resistance to powdery mildew ( Sphaerotheca pannosa).

An antimicrobial protein gene, Ace-AMP1, was introduced into Rosa hybrida cv. Carefree Beauty via Agrobacterium-mediated transformation. A total of 500 putative transgenic plants were obtained from 100 primary embryogenic calli co-cultivated with A. tumefaciens following selection on a regeneration medium containing 100 mg/l kanamycin. Polymerase chain reaction analysis of these putative transgenic lines, using primers for both Ace-AMP1 and neomycin phosphotransferase ( npt II) genes, showed that 62% of these plants were positive for both transgenes. These lines were further confirmed for stable integration of Ace-AMP1 and npt II genes by Southern blotting. Transcription of the Ace-AMP1 transgene in various transgenic rose lines was determined using Northern blotting. Transgenic rose lines inoculated with conidial spores of Sphaerotheca pannosa (Wallr.: Fr.) Lev. var. rosae showed enhanced resistance to powdery mildew using both a detached-leaf assay and an in vivo greenhouse whole-plant assay.