Effects of three promoters in barley transformation by particle bombardment of mature and immature embryos

Abstract

Three different promoters, cauliflower mosaic virus 35S (CaMV 35S), polyubiquitin of maize (Ubi1) and actin1 of rice (Act-1) were compared in a transient assay using particle bombardment of barley mature and immature embryos. The effectiveness of different promoters was compared using a reporter gene expressing β-glucuronidase (GUS). Different levels of GUS gene activity in barley embryos were detected by histochemical analyses. The CaMV 35S promoter showed the lowest level of transient expression in barley cells. The highest activity was observed for the rice (Act-1) promoter and assumed to be a strong promoter in barley. All studied promoters induced about 1% higher number of blue spots in immature barley embryos vs. mature. This study shows that an efficient transformation system could be developed in barley through particle bombardment using constructs based on rice (Act-1) promoter. © 2005 Taylor and Francis Group, LLC.