Submitted to: American Society of Plant Biologists Annual Meeting
Publication Type: Proceedings
Publication Acceptance Date: 7/25/2003
Publication Date: 7/25/2003
Citation: YU, X., BREGITZER, P.P., CHO, M., CHUNG, M.L., YU, H., LEMAUX, P.G. Generation of barley plants containing Ds-bordered transgenes encoding antifungal proteins: a resource for generating marker-free plants with stable expression of fungal resistance. AMERICAN SOCIETY OF PLANT BIOLOGISTS ANNUAL MEETING. 2003.
Technical Abstract: Scab, caused by Fusarium graminearum is a major fungal disease for barley and wheat throughout the world. Infected barley grain is often contaminated by deoxynivalenol, and therefore unacceptable for malting and brewing. Introduction of antifungal proteins into barley by genetic engineering offers the potential to suppress pathogen infection and growth. We are using the Ac/Ds system to produce selectable marker-free transgenic plants containing independent insertions of genes encoding putative antifungal proteins for scab resistance. The putative antifungal genes, tlp1 and tlp4 from oat and tri101 and tri12 from F. sporotrichioides, were cloned into a Ds-bordered, maize ubiquitin- or rice actin promoter-driven expression cassette. The resultant constructs, together with pAHC20 (ubi promoter-bar-nos) or pAct1IHpt4 (actin promoter-hpt-nos), were introduced via bombardment into scutellar tissues of immature embryos or highly regenerative, green tissues of 2 spring cultivars of barley, Golden Promise (GP, a 2-rowed variety) and Drummond (DM, an elite 6-rowed variety). Plants derived from 3 DsUbiTlp1 and 3 DsUbiTlp4 transgenic GP lines were bar-positive. Two DsActTlp1, 1 DsActTlp4 and 3 DsActTri101 lines were generated from hygromycin-resistant highly regenerative tissues of DM. In addition, the Ac-transposase (AcTPase) gene driven by its own Ac promoter was introduced into highly regenerative, green tissues of DM; five putative Ac lines were produced. The AcTPase gene is also being introduced into DM background via backcrossing from AcTPase transgenic GP lines. To assist in characterizing the level of transgene expression, antibodies to the TLP1, TLP4, Tri101 proteins were developed. Further analysis of the transgene insertions and their expression is ongoing.