Poster: Salinity

Abs # 103: Efficient Agrobacterium-mediated transformation of tall fescue for improvement of agronomic traits

Presenter:	Dong, Shujie , sdong@unity.ncsu.edu
Authors	Dong, Shujie  (A)   Qu, Rongda  (A)
Affiliations:	(A): North Carolina State University

An efficient genetic transformation system for tall fescue (Festuca arundinacea Schreb.), using Agrobacterium tumefaciens-mediated T-DNA delivery is established. Seed-derived embryogenic calli were infected with Agrobacterium tumefaciens strains ET1301 and a few other derivatives. The infected calli were selected at 250 mg L^-1 hyg B and the regenerated plantlets, at 50 mg L^-1. Using the protocol developed, 34% of the calli infected were hyg B resistant, and the overall plant transformation frequency (number of independently transformed plants over number of calli infected) was 8%. Stable integration of transgene in plant genome and GUS gene expression was confirmed by Southern blot analysis and GUS histochemical assays, respectively. Low transgene copies (1 or 2 as estimated) were observed in all the transgenic plants analyzed. The whole process from initiation of callus induction to transplantation of green plantlets to the soil takes about six months. Drought tolerance and disease resistant genes were introduced into two elite cultivars (Matador and Coronado) of tall fescue using this efficient transformation system. Among 1846 pieces of calli infected, 31.5% developed into resistant calli under 250 mg L^-1 hyg B selection. PCR assays of the resistant calli confirmed the presence of transgenes in plant. Plantlets are regenerating from the resistant calli under selection. Further analysis of the transgenic plants will be reported.