Marker gene expression driven by the maize ubiquitin promoter in transgenic wheat

Abstract

Selecting a promoter for driving transgene expression is one of the most important factors to consider in a transformation project. Information about the native regulation of the promoter activity is important, but it is also necessary to consider how that activity will be affected when integrated into the genome of the transformed plants. Study of a promoter performance in individually transformed lines provides useful information in this area. The maize ubiquitin 1 (Ubi-1) promoter has been widely used to drive constitutive transgene expression in monocotyledonous plants. However, lack of data on its activity in individual transformed wheat lines constitutes a gap in the understanding and predictability of this promoter's performance. In this paper, we began addressing this problem by examining the expression of the marker gene uidA, coding for P-glucuronidase (GUS), under the control of the maize Ubi-1 promoter in individual transgenic wheat (Eiticum aestivum L.) lines from different wheat varieties. The expression of uidA driven by this promoter depended to a great extent on the specific transformation event. Whilst expression was strong and constitutive in all tissues in some of the lines analysed, there were also transgenic lines in which GUS activity was restricted to only a few tissues. In general the maize Ubi-1 promoter had strong activity in young, metabolically active tissues and in pollen grains.

Ectopic Expression of Constitutively Activated RACB in Barley Enhances Susceptibility to Powdery Mildew and Abiotic Stress

“…The GFP-expressing reporter lines showed GFP expression in all tissues analyzed, including those showing racb-G15V-mediated phenotypes. This is in accordance with observations in wheat (Triticum aestivum), in which the maize ubiquitin promoter drives ubiquitous reporter gene expression, in particular in young metabolically active tissue and pollen grains (Rooke et al, 2000). Hence, RACB-G15V might be directly responsible for shoot and root defects.…”

Stable expression of a defense-related gene in wheat epidermis under transcriptional control of a novel promoter confers pathogen resistance

“…Unlike the current situation in dicotyledonous model systems like tobacco or Arabidopsis, success in promoter development and use in Triticeae cereals remains restricted to ubiquitously active (e.g. Rooke et al, 2000), grain-specific (Altpeter et al, 1996b;Kluth et al, 2002;Furtado et al, 2003), endospermspecific (Cho et al, 1999;Lamacchia et al, 2001) or drought inducible (Xiao and Xue, 2001) promoters. No functional promoter inducible by chemicals or stress has been described in transgenic wheat until present.…”

Engineering deoxynivalenol metabolism in wheat through the expression of a fungal trichothecene acetyltransferase gene

“…Panel B, a separate experiment was done using 35 amplification cycles to detect transcripts from lines 49 and 74 in endosperm RNA. PCR reactions showing comparable actin amplification levels were assembled to compare TRI101 transcript levels focused on endosperm, an organ in which the Ubi-1 promoter was known to be active (Stoger et al 1999;Rooke et al 2000), and from which RNA could readily be extracted. Primers 12 and 8, designed to amplify the 5′ end of the TRI101 cDNA, generated a major PCR product of approximately 500 bp in Lines 49, 156 and 176 (Fig.…”