An improved chemically inducible gene switch that functions in the monocotyledonous plant sugar cane

Abstract

Chemically inducible gene switches can provide precise control over gene expression, enabling more specific analyses of gene function and expanding the plant biotechnology toolkit beyond traditional constitutive expression systems. The alc gene expression system is one of the most promising chemically inducible gene switches in plants because of its potential in both fundamental research and commercial biotechnology applications. However, there are no published reports demonstrating that this versatile gene switch is functional in transgenic monocotyledonous plants, which include some of the most important agricultural crops. We found that the original alc gene switch was ineffective in the monocotyledonous plant sugar cane, and describe a modified alc system that is functional in this globally significant crop. A promoter consisting of tandem copies of the ethanol receptor inverted repeat binding site, in combination with a minimal promoter sequence, was sufficient to give enhanced sensitivity and significantly higher levels of ethanol inducible gene expression. A longer CaMV 35S minimal promoter than was used in the original alc gene switch also substantially improved ethanol inducibility. Treating the roots with ethanol effectively induced the modified alc system in sugar cane leaves and stem, while an aerial spray was relatively ineffective. The extension of this chemically inducible gene expression system to sugar cane opens the door to new opportunities for basic research and crop biotechnology.

GB3.0: a platform for plant bio-design that connects functional DNA elements with associated biological data

“…A step forward in transcriptional control would involve connecting endogenous pathways (e.g. anthocyanin biosynthesis) with externally operable modules such as optogenetic or chemically inducible switches (44,46,53,54). This would allow to externally operate the biochemical and/or physiological status of the plant, for instance anticipating biotic or abiotic threats or triggering the accumulation of target compounds immediately before harvesting.…”

Sugarcane biotechnology: tapping unlimited potential

“…Historically, the gold standard for constitutive, high-level transgene expression in sugarcane has been the maize ubiquitin 1 promoter (Zm-Ubi1) (Kinkema et al 2014b). Recently, additional promoters that have demonstrated potential, or have demonstrated constitutive, tissue-specific, or inducible transgene expression in sugarcane have been identified (Table 2.1).…”

“…Although there has been a substantial research effort to identify a number of constitutive and tissue-specific promoters in sugarcane, the number of promoters available is still relatively few compared with other plant systems that are regularly transformed (Kinkema et al 2014b). In addition to research on gene promoters in sugarcane, molecular techniques exploiting enhancers of gene expression (Kinkema et al 2014b, Rathus et al 1993, codon optimization of transgenes (Kinkema et al, 2014b), transgene silencing suppression (Gao et al 2013), and RNAi interference (Gan et al 2010, Gao et al 2013, Jung et al 2012 are additional valuable tools that may assist in improving transgene expression in sugarcane.…”

Early Growth, Yield and Quality of Sugarcane as Affected by Number of Buds per Sett at Wonji/Shoa Sugar Estate

“…Sugarcane (Saccharum officinarum L.) is the main industrial crop of the world [1] and it is also the leading crop of the world in terms of production [2]. Owing to its multifarious advantages coupled with the immense potential available for its cultivation, Ethiopia has given due focused for the crop to boost production and export for world market [3].…”