Agrobacterium tumefaciens-mediated transformation of Dendrobium lasianthera J.J.Sm: An important medicinal orchid

A protocol for genetic transformation mediated by Agrobacterium tumefaciens and production of transgenic Dendrobium lasianthera has been developed for the first time. The 8-week-old protocorm explants were used as target of transformation with Agrobacterium tumefaciens strain LBA4404 carrying plasmid pG35SKNAT1. Several parameters such as infection period, Agrobacterium density, concentration of acetosyringone, and co-cultivation period were evaluated for the transformation efficiency. The data were analyzed using one-way analysis of variance (ANOVA) and Duncan's Multiple Range Test (DMRT) with p < 0.05. Subsequently, KNAT1 gene expression was confirmed by polymerase chain reaction (PCR) analysis. The highest efficiency of transformation (70%) obtained from protocorm explants infected with Agrobacterium culture was at the OD(600) concentration of 0.6 for 30 min, and co-cultivated with acetosyringone 100 µM for 5 days. The results of confirmation by PCR analysis show that the KNAT1 gene has been integrated and expressed in the genome of Dendrobium lasianthera transgenic.