| Perennial ryegrass (Lolium perenne L.) is an agronomically important grass grown in the temperate regions of the world. It is widely used as a forage crop and turfgrass for its high quality and yield. However, its growth is limited due to its inability to survive in extreme winter temperatures. The aim of the present study is to obtain cold tolerant perennial ryegrass by transforming it the cold regulated transcriptional activator Lp CBF3 gene using the Agrobacterium-mediated gene transfer method and evaluate overexpression of the LpCBF3 gene under the control of the constitutive promoter, cauliflower mosaic virus 35S (CaMV35S). Embryogenic calli of perennial ryegrass cv. 'Inspire' were transformed by an Agrobacterium strain EHA105 containing a modified pFGC5941 plasmid.;Results of the study showed that transgenic perennial ryegrass overexpressing the LpCBF3 gene was successfully regenerated. Presence and stable integration of the gene in the genome was confirmed by PCR analysis and Southern hybridization. Glufosinate resistance and electrolyte leakage tests indicated the expression of the gene in the transformants. Cold acclimated transgenic plants showed increased tolerance to freezing temperature. In this study, 35S:LpCBF3 transgenic plants did not show growth retardation but had reduced tillering ability. |
