Ectopic Expression of an Oat Thionin Gene in Carnation Plants Confers Enhanced Resistance to Bacterial Wilt Disease

Under the control of Arabidopsis triptophan synthase β subunit promoter (PTSB1), the oat thionin gene (Asthi1) was introduced into carnation (Dianthus caryphyllus L.) via Agrobacterium-mediated gene transfer. Leaf bases of three cultivars of carnation (‘Scania’, ‘Percian Pink-Sim’ and ‘U. Conn. White Sim’) were infected with Agrobacterium harboring the binary vector with PTSB1::Asthi1 and hygromycin genes, and cultured on the medium containing hygromycin. Independent 99 lines resistant to hygromycin were regenerated and the introduction of the transgene was confirmed in 11 lines by polymerase chain reaction. Transgenic carnation plants exhibited the resistance against infection with Burkholderia caryophylli which caused bacterial wilt, and the levels of resistance correlated with those of the thionin gene transcript.