Arabidopsis DREB1A/CBF3 bestowed transgenic tall fescue increased tolerance to drought stress.

In order to improve drought tolerance of tall fescue (Festuca arundinacea Schreb.), an important perennial cool-season grass, we introduced Arabidopsis DREB1A/CBF3 driven by the inducible rd29A promoter into tall fescue mediated by Agrobacterium tumefaciens strains AGL1. PCR and Southern blot analysis confirmed that DREB1A/CBF3 gene had been integrated into the genome of tall fescue. AtDREB1A gene was stably inherited and expressed in T(1) plants, as indicated by PCR, RT-PCR and Western blotting analysis. The transgenic plants also showed an increased expression of AtP5CS2, which was confirmed to be a downstream target gene of DREB in Arabidopsis. We found that the transgenic tall fescue showed increased resistance to drought and accumulated high level of proline, indicating ability of the CBF3 gene to induce stress related response in tall fescue. The result here provides evidence for drought improvement of tall fescue via transformation with stress-related transcription factor and stress-induced promoter.