Abstract
We have achieved efficient transformation system for forage-type tall fescue plants by Agrobacterium tumefaciens. Mature seed-derived embryogenic calli were infected and co-cultivated with each of three A. tumefaciens strains, all of which harbored a standard binary vector pIG121Hm encoding the neomycin phosphotransferase II (NPTII), hygromycin phosphotransferase (HPT) and intron-containing β-glucuronidase (intron-GUS) genes in the T-DNA region. Transformation efficiency was influenced by the A. tumefaciens strain, addition of the phenolic compound acetosyringone and duration of vacuum treatment. Of the three A. tumefaciens strains tested, EHA101/pIG121Hm was found to be most effective followed by GV3101/pIG121Hm and LBA4404/pIG121Hm for transient GUS expression after 3 days co-cultivation. Inclusion of 100 µM acetosyringone in both the inoculation and co-cultivation media lead to an improvement in transient GUS expression observed in targeted calli. Vacuum treatment during infection of calli with A. tumefaciens strains increased transformation efficiency. The highest stable transformation efficiency of transgenic plants was obtained when mature seed-derived calli infected with A. tumefaciens EHA101/pIG121Hm in the presence of 100 µM acetosyringone and vacuum treatment for 30 min. Southern blot analysis indicated integration of the transgene into the genome of tall fescue. The transformation system developed in this study would be useful for Agrobacterium-mediated genetic transformation of tall fescue plants with genes of agronomic importance. (Asian-Aust. J. Anim. Sci. 2004. Vol 17, No. 10 : 1390-1394)
Highlights
Tall fescue (Festuca arundinacea Schreb.) is an openpollinated, perennial, cool-season grass species widely used for forage (Buckner et al, 1979)
Transgenic tall fescue plants have been obtained by direct gene transfer methods such as polyethyleneglycol- or electroporation-mediated DNA uptake into protoplasts (Ha et al, 1992; Dalton et al, 1995) and microprojectile bombardment of cell suspension cultures (Spangenberg et al, 1995; Cho et al, 2000)
Recent reports demonstrate that Agrobacterium-mediated transformation offers several advantages in comparison with microprojectile bombardment method such as transfer of relatively large segments of DNA with little rearrangement and integration of low copy numbers of T-DNA to active regions of chromosome (Hiei et al, 1994)
Summary
Tall fescue (Festuca arundinacea Schreb.) is an openpollinated, perennial, cool-season grass species widely used for forage (Buckner et al, 1979). The highest stable transformation efficiency of transgenic plants was obtained when mature seed-derived calli infected with A. tumefaciens EHA101/pIG121Hm in the presence of 100 μM acetosyringone and vacuum treatment for 30 min. Addition of 100 μM acetosyringone to both inoculation and co-cultivation media resulted in the highest frequency of GUS expressing calli, and the differences were significant between this concentration and the other concentrations of acetosyringone (Table 1).
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
