in the oat background, and the salt tolerance trait com- plexity (Cushman and Bohnert, 2000). Crop improve- A major cause of oat crop yield loss worldwide is osmotic stress ment strategies that are based on the use of new technol- duetodroughtand/orsalinity.Thisstudyinvestigatedthethirdgenera- tionoftransgenicoat(AvenasativaL.)expressingbarleyHVA1stress ogies, such as biotechnology, can be used in conjunction tolerance, -glucuronidase (uidA; gus) and bar herbicide resistance with traditional breeding efforts (Abebe et al., 2003; genes. Transgenic plants showed normal 9:7 third generation inheri- Epstein et al., 1980; Ribaut and Hoisington, 1998), offer- tance for glufosinate ammonium herbicide resistance. Molecular and ing a responsible way to enhance agricultural productiv- histochemical studies confirmed the presence and stable expression ity. Biotechnology could help eliminate many obstacles of all three genes. Compared with the nontransgenic control plants, limiting crop production in developing countries. The transgenicR3plantsexhibitedgreatergrowthandshowedasignificant development of crops with the internal capacity to with- (P 0.05) increase in tolerance to salt stress conditions (200 mM stand abiotic stresses would help to reduce the use of NaCl) for traits including number of days to heading, plant height, water (FAO, 1999), thus promoting sustainable yields flag leaf area, root length, panicle length, number of spikelets/panicle,