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Abstract

A 1369 bp DNA fragment (Sc) was isolated from a full-length clone of sugarcane bacilliform badnavirus (ScBV) and was shown to have promoter activity in transient expression assays using monocot (banana, maize, millet and sorghum) and dicot plant species (tobacco, sunflower, canola and Nicotiana benthamiana). This promoter was also tested for stable expression in transgenic banana and tobacco plants. These experiments showed that this promoter could drive high-level expression of the beta-glucuronidase (GUS) reporter gene in most plant cells. The expression level was comparable to the maize ubiquitin promoter in standardised transient assays in maize. In transgenic banana plants the expression levels were variable for different transgenic lines but was generally comparable with the activities of both the maize ubiquitin promoter and the enhanced cauliflower mosaic virus (CaMV) 35S promoter. The Sc promoter appears to express in a near-constitutive manner in transgenic banana and tobacco plants. The promoter from sugarcane bacilliform virus represents a useful tool for the high-level expression of foreign genes in both monocot and dicot transgenic plants that could be used similarly to the CaMV 35S or maize polyubiquitin promoter.

A novel Sugarcane bacilliform virus promoter confers gene expression preferentially in the vascular bundle and storage parenchyma of the sugarcane culm

“…The activity of SCBV21 in monocots and dicots was evaluated by adopting a transient gene expression assay, previously shown to be rapid, quantifiable, and reproducible for the comparative analysis of the activity of different promoters [34, 41]. Transient and stable expression analyses using SCBV21 fusions to EYFP and GUS genes ( SCBV21:EYFP and SCBV21:GUS ) showed that the promoter is functional in both monocots (sugarcane and sweet sorghum) and dicots ( N. benthamiana and lima bean), consistent with the activity of the SCBV promoters from SCBMOV-MOR [19, 20, 30, 56] and SCBIMV-QLD species [57]. …”

“…The extensive genetic diversity of SCBV has been reported in the promoter [57], RT/RNase H [29], and full genomic [25] sequences. In this study, we cloned, mapped, and functionally characterized a novel SCBV promoter, SCBV21 , in addition to two SCBV promoters previously developed from SCBIMV-QLD [57] and SCBMOV-MOR [19, 20]. SCBV21 shared low nt sequence identity with the published SCBIMV-QLD and SCBMOV-MOR promoters, respectively based on the full promoter sequence, showing that it is a distinct promoter [58].…”

“…For instance, the SCBMOV-MOR promoter was shown to confer high levels of constitutive GUS expression in vegetative and reproductive tissues of both monocots (sugarcane, banana, oat, barley, and wheat) and dicots (Arabidopsis and tobacco) [18–20]. However, differences in SCBMOV-MOR promoter specificity were detected among species and tissues, i.e., stronger GUS activity in most tissues of oat and barley than in wheat [30]; and mainly vascular GUS activity in root of banana but constitutive in tobacco [20]. The SCBIMV-QLD promoter was reported to be the strongest in driving reporter gene expression in the leaves, meristems, and roots of glasshouse-grown sugarcane [57].…”

“…These include the various enhanced 35S promoters from the dicot-infecting DNA Cauliflower mosaic virus (CaMV) [13] or the promoters of monocot-infecting DNA viruses like Rice tungro bacilliform virus (RTBV) [14, 15], Commelina yellow mottle virus [16], Taro bacilliform virus [17], Banana streak virus (BSV) [18], and Sugarcane bacilliform virus (SCBV) [19, 20]. Viral promoters derived from monocot-infecting DNA viruses are of particular interest because they tend to confer a tissue-specific gene expression, specifically in the vascular system [14, 16–20]. …”

Comparison of the impact of viral and plant-derived promoters regulating selectable marker gene on maize transformation and transgene expression

“…Modification by adding introns or enhancers containing fragments from either monocots or dicots improve the utility of CaMV promoter in transformation systems of maize and bluegrass (Vain et al 1996). SCBV promoter from the plant virus, sugarcane bacilliform virus, is active in monocots (Tzafrir et al 1998), and has been shown to drive high levels of gene expression in banana (Schenk et al 1999, 2001), sugarcane (Braithwaite et al 2004) and maize (Davies et al 2014). …”